Selection in Blazor Gantt Chart Component

14 Sep 202124 minutes to read

Selection provides an option to highlight a row or a cell. It can be done using arrow keys or by scrolling down the mouse. To disable selection in the Gantt Chart component, set the AllowSelection to false.

The Gantt Chart component supports two types of selection that can be set by using the SelectionSettings.Type property. They are:

  • Single: Sets a single value by default and allows only selection of a single row or a cell.
  • Multiple: Allows you to select multiple rows or cells. To perform the multi-selection, press and hold the CTRL key and click the desired rows or cells.

Selection Mode

The Blazor Gantt Chart component supports three types of selection modes that can be set by using the SelectionSettings.Mode. They are:

  • Row: Allows you to select only rows, and the row value is set by default.
  • Cell: Allows you to select only cells.
  • Both: Allows you to select rows and cells at the same time.
@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<SfGantt DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Both"></GanttSelectionSettings>

</SfGantt>

@code{
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Row

The row selection in the Gantt Chart component can be enabled or disabled using the AllowSelection property. You can get the selected row object using the GetSelectedRecordsAsync method. The following code example shows how to disable the row selection in Gantt Chart.

@using Syncfusion.Blazor.Gantt
    <SfGantt DataSource="@TaskCollection" Height="450px" Width="700px" AllowSelection="false">
        <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
        </GanttTaskFields>
    </SfGantt>

@code{
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Row selection is the default type of Gantt Chart selection mode.

Selecting a Row on Initial Load

You can select a row at the time of loading by setting the index of the row to the SelectedRowIndex property. Find the following code example for details.

@using Syncfusion.Blazor.Gantt
    <SfGantt DataSource="@TaskCollection" Height="450px" Width="700px" AllowSelection="true" SelectedRowIndex="3">
        <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
        </GanttTaskFields>
    </SfGantt>

@code{
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Initial Selection in Blazor Gantt Chart

Selecting a Row dynamically

You can also select a row dynamically using the SelectRowAsync method. The following code demonstrates how to select a row dynamically by clicking the custom button.

@using Syncfusion.Blazor.Gantt
<button @onclick="SelectRow">Select Row</button>
<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
</SfGantt>

@code{
    public SfGantt<TaskData> Gantt;
    public void SelectRow()
    {
        this.Gantt.SelectRowAsync(2);
    }
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Row Selection in Blazor Gantt Chart

Multiple Row Selection

You can select multiple rows by setting the SelectionSettings.Type property to Multiple. You can select more than one row by holding down the CTRL key while selecting multiple rows. The following code example explains how to enable multiple selection in Gantt Chart.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<SfGantt DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Row" Type="Syncfusion.Blazor.Grids.SelectionType.Multiple"></GanttSelectionSettings>
</SfGantt>

@code{
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Multiple Row Selection in Blazor Gantt Chart

Selecting Multiple Rows dynamically

You can also select rows dynamically using the SelectRowsAsync method. The following code demonstrates how to select rows dynamically by clicking the custom button.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<button @onclick="SelectRows">Select Rows</button>
<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Row" Type="Syncfusion.Blazor.Grids.SelectionType.Multiple"></GanttSelectionSettings>
</SfGantt>

@code{
    public SfGantt<TaskData> Gantt;
    public void SelectRows()
    {
        this.Gantt.SelectRowsAsync(new double[] {1,2,3});
    }
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Selecting Multiple Rows Dynamically in Blazor Gantt Chart

Cell

You can select a cell in the Gantt Chart component by setting the SelectionSettings.Mode property to cell. You can get the selected cell information using the GetSelectedRowCellIndexes method. This method returns the result as an object collection, which has CellIndexes and RowIndex information of the selected cells.

Find the code example below to enable the cell selection in Gantt Chart.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<SfGantt DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Cell"></GanttSelectionSettings>
</SfGantt>

@code{
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Cell Selection in Blazor Gantt Chart

Selecting Multiple Cells

You can select multiple cells by setting the SelectionSettings.Type property to multiple and the SelectionSettings.Mode property to Cell. Multiple cells can be selected by holding the CTRL key and selecting the cells. The following code example demonstrates how to select multiple cells.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<SfGantt DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Cell" Type="Syncfusion.Blazor.Grids.SelectionType.Multiple"></GanttSelectionSettings>
</SfGantt>

@code{
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Multiple Cell Selection in Blazor Gantt Chart

Selecting a Cell dynamically

You can select a cell dynamically using the SelectCellAsync method. Refer to the following code example for details.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<button @onclick="SelectCell">Select Cell</button>
<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Cell"></GanttSelectionSettings>
</SfGantt>

@code{
    public SfGantt<TaskData> Gantt;
    public void SelectCell()
    {
        this.Gantt.SelectCellAsync( new ValueTuple<int, int> (1, 2) );
    }
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Selecting Cells Dynamically in Blazor Gantt Chart

Customize Cell Selection action

While selecting a cell in Gantt Chart, the CellSelecting and CellSelected event will be triggered. The CellSelecting event will be triggered on initialization of cell selection action, and you can get the current selecting cell information to prevent the selection of a particular cell in a particular row. The CellSelected event will be triggered on completion of cell selection action, and you can get the current selected cell’s information. The following code example demonstrates how to prevent the selection of the cell using the CellSelecting event.

@using Syncfusion.Blazor.Gantt
<SfGantt DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="Syncfusion.Blazor.Grids.SelectionMode.Cell"></GanttSelectionSettings>
    <GanttEvents CellSelecting="CellSelecting" TValue="TaskData"></GanttEvents>
</SfGantt>

@code{
    public void CellSelecting(Syncfusion.Blazor.Grids.CellSelectingEventArgs<TaskData> args)
    {
        if (args.Data.TaskId == 2)
        {
            args.Cancel = true;
        }
    }
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Toggle Selection

The toggle selection allows you to select and deselect a specific row or cell. To enable toggle selection, set the EnableToggle property of the SelectionSettings to true. If you click the selected row or cell, then it will be deselected and vice versa.
By default, the EnableToggle property is set to false.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<button @onclick="DisableToggle">Disable Toggle</button>
<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Row" Type="Syncfusion.Blazor.Grids.SelectionType.Multiple" EnableToggle="@toggle"></GanttSelectionSettings>
</SfGantt>

@code{
    public SfGantt<TaskData> Gantt;
    public bool toggle = true;
    public void DisableToggle()
    {
        this.toggle = false;
    }
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Clear Selection

You can clear the selected cells and selected rows by using a method called ClearSelectionAsync. The following code example demonstrates how to clear the selected rows in Gantt Chart.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<button @onclick="select">Select Rows</button>
<button @onclick="clear">Clear Selection</button>
<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Row" Type="Syncfusion.Blazor.Grids.SelectionType.Multiple"></GanttSelectionSettings>
</SfGantt>

@code{
    public SfGantt<TaskData> Gantt;
    public void select()
    {
        this.Gantt.SelectRowsAsync(new double[] {1,2,3});
    }
    public void clear() {
        this.Gantt.ClearSelectionAsync();
    }
    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }
    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };

    return Tasks;
}
}

Get Selected Row Indexes and Records

You can get the selected row indexes by using the GetSelectedRowIndexesAsync method. And by using GetSelectedRecordsAsync method, you can get the selected record details.

@using Syncfusion.Blazor.Gantt
@using Syncfusion.Blazor.Grids
<SfGantt @ref="Gantt" DataSource="@TaskCollection" Height="450px" Width="700px">
    <GanttTaskFields Id="TaskId" Name="TaskName" StartDate="StartDate" EndDate="EndDate" Duration="Duration" Progress="Progress" Child="SubTasks">
    </GanttTaskFields>
    <GanttSelectionSettings Mode="SelectionMode.Row" Type="Syncfusion.Blazor.Grids.SelectionType.Multiple"></GanttSelectionSettings>
    <GanttEvents TValue="TaskData" RowSelected="rowSelect"></GanttEvents>
</SfGantt>

@code{
    public SfGantt<TaskData> Gantt;
    public void rowSelect(RowSelectEventArgs<TaskData> args)
    {
        Console.WriteLine(this.Gantt.GetSelectedRowIndexesAsync());
        Console.WriteLine(this.Gantt.GetSelectedRecordsAsync());
    }

    public List<TaskData> TaskCollection { get; set; }
    protected override void OnInitialized()
    {
        this.TaskCollection = GetTaskCollection();
    }

    public class TaskData
    {
        public int TaskId { get; set; }
        public string TaskName { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }
        public string Duration { get; set; }
        public int Progress { get; set; }
        public List<TaskData> SubTasks { get; set; }
    }

    public static List <TaskData> GetTaskCollection() {
    List <TaskData> Tasks = new List <TaskData> () {
        new TaskData() {
            TaskId = 1,
            TaskName = "Project initiation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 2,
                    TaskName = "Identify Site location",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 3,
                    TaskName = "Perform soil test",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "4",
                    Progress = 40,
                },
                new TaskData() {
                    TaskId = 4,
                    TaskName = "Soil test approval",
                    StartDate = new DateTime(2019, 04, 02),
                    Duration = "0",
                    Progress = 30
                },
            })
        },
        new TaskData() {
            TaskId = 5,
            TaskName = "Project estimation",
            StartDate = new DateTime(2019, 04, 02),
            EndDate = new DateTime(2019, 04, 21),
            SubTasks = (new List <TaskData> () {
                new TaskData() {
                    TaskId = 6,
                    TaskName = "Develop floor plan for estimation",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 30,
                },
                new TaskData() {
                    TaskId = 7,
                    TaskName = "List materials",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "3",
                    Progress = 40
                },
                new TaskData() {
                    TaskId = 8,
                    TaskName = "Estimation approval",
                    StartDate = new DateTime(2019, 04, 04),
                    Duration = "0",
                    Progress = 30,
                }
            })
        }
    };
    return Tasks;
    }
}