Excel Export in Blazor TreeGrid Component

10 Oct 202524 minutes to read

The Excel export feature allows exporting TreeGrid data to an Excel document using the ExportToExcelAsync method. To enable Excel export, set the AllowExcelExport property to true.

RAZOR

@using TreeGridComponent.Data;
@using Syncfusion.Blazor.TreeGrid;

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" AllowExcelExport="true" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1"
             Toolbar="@(new List<string>() { "ExcelExport" })">
    <TreeGridEvents OnToolbarClick="ToolbarClickHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" Format="C2" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="StartDate" HeaderText=" Start Date" Format="yMd" Type="Syncfusion.Blazor.Grids.ColumnType.Date" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right" Width="100"></TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

    public List<TreeData> TreeGridData { get; set; }

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }

    private void ToolbarClickHandler(Syncfusion.Blazor.Navigations.ClickEventArgs Args)
    {
        if(Args.Item.Text == "Excel Export")
        {
            this.TreeGrid.ExportToExcelAsync();
        }
    }
}

C#

namespace TreeGridComponent.Data {

public class TreeData
    {
       
            public int TaskId { get; set;}
            public string TaskName { get; set;}
            public int? Duration { get; set;}
            public int? Progress { get; set;}
            public string Priority { get; set;}
            public int? ParentId { get; set;}
      
        public static List<TreeData> GetSelfDataSource()
        {
            List<TreeData> BusinessObjectCollection = new List<TreeData>();
            BusinessObjectCollection.Add(new TreeData() { TaskId = 1,TaskName = "Parent Task 1",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 2,TaskName = "Child task 1",Progress = 80,Priority = "Low",ParentId = 1 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 3,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Critical",ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 4,TaskName = "Child task 3",Duration = 6,Priority = "High",Progress = 77,ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 5,TaskName = "Parent Task 2",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 6,TaskName = "Child task 1",Duration = 4,Progress = 80,Priority = "Critical",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 7,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Low",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 8,TaskName = "Child task 3",Duration = 6,Progress = 77,Priority = "High",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 9,TaskName = "Child task 4",Duration = 6,Progress = 77,Priority = "Low",ParentId = 5});
            return BusinessObjectCollection;
        }
    }
}

To customize excel export

The excel export provides an option to customize mapping of the TreeGrid to excel document.

Export current page

The excel export provides an option to export the current page into excel. To export current page, define exportType to CurrentPage.

RAZOR

@using TreeGridComponent.Data;
@using Syncfusion.Blazor.TreeGrid;

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" AllowExcelExport="true" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1"
             Toolbar="@(new List<string>() { "ExcelExport" })">
    <TreeGridEvents OnToolbarClick="ToolbarClickHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" Format="C2" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="StartDate" HeaderText=" Start Date" Format="yMd" Type="Syncfusion.Blazor.Grids.ColumnType.Date" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right" Width="100"></TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

    public List<TreeData> TreeGridData { get; set; }

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }

    private void ToolbarClickHandler(Syncfusion.Blazor.Navigations.ClickEventArgs Args)
    {
        if(Args.Item.Text == "Excel Export")
        {
            Syncfusion.Blazor.Grids.ExcelExportProperties ExportProperties = new Syncfusion.Blazor.Grids.ExcelExportProperties();
            ExportProperties.ExportType = Syncfusion.Blazor.Grids.ExportType.CurrentPage;
            this.TreeGrid.ExportToExcelAsync(ExportProperties);
        }
    }
}

C#

namespace TreeGridComponent.Data {

public class TreeData
    {
       
            public int TaskId { get; set;}
            public string TaskName { get; set;}
            public int? Duration { get; set;}
            public int? Progress { get; set;}
            public string Priority { get; set;}
            public int? ParentId { get; set;}
      
        public static List<TreeData> GetSelfDataSource()
        {
            List<TreeData> BusinessObjectCollection = new List<TreeData>();
            BusinessObjectCollection.Add(new TreeData() { TaskId = 1,TaskName = "Parent Task 1",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 2,TaskName = "Child task 1",Progress = 80,Priority = "Low",ParentId = 1 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 3,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Critical",ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 4,TaskName = "Child task 3",Duration = 6,Priority = "High",Progress = 77,ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 5,TaskName = "Parent Task 2",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 6,TaskName = "Child task 1",Duration = 4,Progress = 80,Priority = "Critical",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 7,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Low",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 8,TaskName = "Child task 3",Duration = 6,Progress = 77,Priority = "High",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 9,TaskName = "Child task 4",Duration = 6,Progress = 77,Priority = "Low",ParentId = 5});
            return BusinessObjectCollection;
        }
    }
}

Export hidden columns

The excel export provides an option to export hidden columns of TreeGrid by defining includeHiddenColumn as true.

RAZOR

@using TreeGridComponent.Data;
@using Syncfusion.Blazor.TreeGrid;

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" AllowExcelExport="true" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1"
            Toolbar="@(new List<string>() { "ExcelExport" })">
    <TreeGridEvents OnToolbarClick="ToolbarClickHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" Format="C2" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="StartDate" Visible="false" HeaderText=" Start Date" Format="yMd" Type="Syncfusion.Blazor.Grids.ColumnType.Date" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right" Width="100"></TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

    public List<TreeData> TreeGridData { get; set; }

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }

    private void ToolbarClickHandler(Syncfusion.Blazor.Navigations.ClickEventArgs Args)
    {
        if(Args.Item.Text == "Excel Export")
        {
            Syncfusion.Blazor.Grids.ExcelExportProperties ExportProperties = new Syncfusion.Blazor.Grids.ExcelExportProperties();
            ExportProperties.IncludeHiddenColumn = true;
            this.TreeGrid.ExportToExcelAsync(ExportProperties);
        }
    }
        }

C#

namespace TreeGridComponent.Data {

public class TreeData
    {
       
            public int TaskId { get; set;}
            public string TaskName { get; set;}
            public int? Duration { get; set;}
            public int? Progress { get; set;}
            public string Priority { get; set;}
            public int? ParentId { get; set;}
      
        public static List<TreeData> GetSelfDataSource()
        {
            List<TreeData> BusinessObjectCollection = new List<TreeData>();
            BusinessObjectCollection.Add(new TreeData() { TaskId = 1,TaskName = "Parent Task 1",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 2,TaskName = "Child task 1",Progress = 80,Priority = "Low",ParentId = 1 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 3,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Critical",ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 4,TaskName = "Child task 3",Duration = 6,Priority = "High",Progress = 77,ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 5,TaskName = "Parent Task 2",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 6,TaskName = "Child task 1",Duration = 4,Progress = 80,Priority = "Critical",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 7,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Low",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 8,TaskName = "Child task 3",Duration = 6,Progress = 77,Priority = "High",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 9,TaskName = "Child task 4",Duration = 6,Progress = 77,Priority = "Low",ParentId = 5});
            return BusinessObjectCollection;
        }
    }
}

Theme

The excel export provides an option to include theme for exported excel document.

To apply theme in exported Excel, define the theme in export properties.

RAZOR

@using TreeGridComponent.Data;
@using Syncfusion.Blazor.TreeGrid;

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" AllowExcelExport="true" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1"
             Toolbar="@(new List<string>() { "ExcelExport" })">
    <TreeGridEvents OnToolbarClick="ToolbarClickHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" Format="C2" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="StartDate" HeaderText=" Start Date" Format="yMd" Type="Syncfusion.Blazor.Grids.ColumnType.Date" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right" Width="100"></TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

    public List<TreeData> TreeGridData { get; set; }

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }

    private void ToolbarClickHandler(Syncfusion.Blazor.Navigations.ClickEventArgs Args)
    {
        if(Args.Item.Text == "Excel Export")
        {
            Syncfusion.Blazor.Grids.ExcelExportProperties ExportProperties = new Syncfusion.Blazor.Grids.ExcelExportProperties();
            Syncfusion.Blazor.Grids.ExcelTheme Theme = new Syncfusion.Blazor.Grids.ExcelTheme();

            Syncfusion.Blazor.Grids.ExcelStyle ThemeStyle = new Syncfusion.Blazor.Grids.ExcelStyle()
            {
                FontName = "Segoe UI",
                FontColor = "#666666"
            };

            Theme.Header = ThemeStyle;
            Theme.Record = ThemeStyle;
            Theme.Caption = ThemeStyle;

            this.TreeGrid.ExportToExcelAsync(ExportProperties);
        }
    }
}

C#

namespace TreeGridComponent.Data {

public class TreeData
    {
       
            public int TaskId { get; set;}
            public string TaskName { get; set;}
            public int? Duration { get; set;}
            public int? Progress { get; set;}
            public string Priority { get; set;}
            public int? ParentId { get; set;}
      
        public static List<TreeData> GetSelfDataSource()
        {
            List<TreeData> BusinessObjectCollection = new List<TreeData>();
            BusinessObjectCollection.Add(new TreeData() { TaskId = 1,TaskName = "Parent Task 1",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 2,TaskName = "Child task 1",Progress = 80,Priority = "Low",ParentId = 1 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 3,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Critical",ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 4,TaskName = "Child task 3",Duration = 6,Priority = "High",Progress = 77,ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 5,TaskName = "Parent Task 2",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 6,TaskName = "Child task 1",Duration = 4,Progress = 80,Priority = "Critical",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 7,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Low",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 8,TaskName = "Child task 3",Duration = 6,Progress = 77,Priority = "High",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 9,TaskName = "Child task 4",Duration = 6,Progress = 77,Priority = "Low",ParentId = 5});
            return BusinessObjectCollection;
        }
    }
}

NOTE

By default, material theme is applied to exported excel document.

File name for exported document

The file name can be assigned for the exported document by defining fileName property in excel export properties.

RAZOR

@using TreeGridComponent.Data;
@using Syncfusion.Blazor.TreeGrid;

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" AllowExcelExport="true" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1"
             Toolbar="@(new List<string>() { "ExcelExport" })">
    <TreeGridEvents OnToolbarClick="ToolbarClickHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" Format="C2" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="StartDate" HeaderText=" Start Date" Format="yMd" Type="Syncfusion.Blazor.Grids.ColumnType.Date" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right" Width="100"></TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

    public List<TreeData> TreeGridData { get; set; }

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }

    private void ToolbarClickHandler(Syncfusion.Blazor.Navigations.ClickEventArgs Args)
    {
        if(Args.Item.Text == "Excel Export")
        {
            Syncfusion.Blazor.Grids.ExcelExportProperties ExportProperties = new Syncfusion.Blazor.Grids.ExcelExportProperties();
            ExportProperties.FileName = "New.xlsx";
            this.TreeGrid.ExportToExcelAsync(ExportProperties);
        }
    }
}

C#

namespace TreeGridComponent.Data {

public class TreeData
    {
       
            public int TaskId { get; set;}
            public string TaskName { get; set;}
            public int? Duration { get; set;}
            public int? Progress { get; set;}
            public string Priority { get; set;}
            public int? ParentId { get; set;}
      
        public static List<TreeData> GetSelfDataSource()
        {
            List<TreeData> BusinessObjectCollection = new List<TreeData>();
            BusinessObjectCollection.Add(new TreeData() { TaskId = 1,TaskName = "Parent Task 1",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 2,TaskName = "Child task 1",Progress = 80,Priority = "Low",ParentId = 1 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 3,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Critical",ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 4,TaskName = "Child task 3",Duration = 6,Priority = "High",Progress = 77,ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 5,TaskName = "Parent Task 2",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 6,TaskName = "Child task 1",Duration = 4,Progress = 80,Priority = "Critical",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 7,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Low",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 8,TaskName = "Child task 3",Duration = 6,Progress = 77,Priority = "High",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 9,TaskName = "Child task 4",Duration = 6,Progress = 77,Priority = "Low",ParentId = 5});
            return BusinessObjectCollection;
        }
    }
}

To persist collapsed state

The collapsed state can be persisted in the exported document by defining IsCollapsedStatePersist property as true in the TreeGridExcelExportProperties parameter of the ExportToExcelAsync method.

RAZOR

@using TreeGridComponent.Data;
@using Syncfusion.Blazor.TreeGrid;

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" AllowExcelExport="true" IdMapping="TaskId" ParentIdMapping="ParentId" TreeColumnIndex="1"
             Toolbar="@(new List<string>() { "ExcelExport" })">
    <TreeGridEvents OnToolbarClick="ToolbarClickHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160"></TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" Format="C2" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="StartDate" HeaderText=" Start Date" Format="yMd" Type="Syncfusion.Blazor.Grids.ColumnType.Date" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right" Width="100"></TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

    public List<TreeData> TreeGridData { get; set; }

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }

    private void ToolbarClickHandler(Syncfusion.Blazor.Navigations.ClickEventArgs Args)
    {
        if(Args.Item.Text == "Excel Export")
        {
            Syncfusion.Blazor.TreeGrid.TreeGridExcelExportProperties ExportProperties = new Syncfusion.Blazor.TreeGrid.TreeGridExcelExportProperties();
            ExportProperties.IsCollapsedStatePersist = true;
            this.TreeGrid.ExportToExcelAsync(ExportProperties);
        }
    }
}

C#

namespace TreeGridComponent.Data {

public class TreeData
    {
       
            public int TaskId { get; set;}
            public string TaskName { get; set;}
            public int? Duration { get; set;}
            public int? Progress { get; set;}
            public string Priority { get; set;}
            public int? ParentId { get; set;}
      
        public static List<TreeData> GetSelfDataSource()
        {
            List<TreeData> BusinessObjectCollection = new List<TreeData>();
            BusinessObjectCollection.Add(new TreeData() { TaskId = 1,TaskName = "Parent Task 1",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 2,TaskName = "Child task 1",Progress = 80,Priority = "Low",ParentId = 1 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 3,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Critical",ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 4,TaskName = "Child task 3",Duration = 6,Priority = "High",Progress = 77,ParentId = 2 });
            BusinessObjectCollection.Add(new TreeData() { TaskId = 5,TaskName = "Parent Task 2",Duration = 10,Progress = 70,Priority = "Critical",ParentId = null});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 6,TaskName = "Child task 1",Duration = 4,Progress = 80,Priority = "Critical",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 7,TaskName = "Child Task 2",Duration = 5,Progress = 65,Priority = "Low",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 8,TaskName = "Child task 3",Duration = 6,Progress = 77,Priority = "High",ParentId = 5});
            BusinessObjectCollection.Add(new TreeData() { TaskId = 9,TaskName = "Child task 4",Duration = 6,Progress = 77,Priority = "Low",ParentId = 5});
            return BusinessObjectCollection;
        }
    }
}

Limitations

Limitations

Microsoft Excel supports up to seven nested levels in outlines. If the TreeGrid exceeds this depth, the document will be exported without outline formatting.

Refer to the official documentation:
Microsoft Limitation.