Prevent default Tree Grid action in Blazor TreeGrid Component

17 Dec 20236 minutes to read

The default Tree Grid actions can be prevented by canceling them in the RowCreating event.

This is demonstrated in the below sample code where the Add operation is prevented by setting Cancel argument value of the RowCreating event to false.

RAZOR

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

<SfTreeGrid @ref="TreeGrid" DataSource="@TreeGridData" IdMapping="TaskId" ParentIdMapping="ParentId"
            TreeColumnIndex="1" AllowPaging="true" Toolbar="@(new List<string>() { "Add", "Delete", "Edit","Update", "Cancel" })">
    <TreeGridEvents RowCreating="RowCreatingHandler" TValue="TreeData"></TreeGridEvents>
    <TreeGridEditSettings AllowAdding="true" AllowEditing="true" AllowDeleting="true"></TreeGridEditSettings>
    <TreeGridPageSettings PageSize="8"></TreeGridPageSettings>
    <TreeGridColumns>
        <TreeGridColumn Field="TaskId" HeaderText="Task ID" IsPrimaryKey="true" Width="80" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
        <TreeGridColumn Field="TaskName" HeaderText="Task Name" Width="160">
        </TreeGridColumn>
        <TreeGridColumn Field="Priority" HeaderText="Priority" Width="80">
        </TreeGridColumn>
        <TreeGridColumn Field="Duration" HeaderText="Duration" Width="100" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right">
        </TreeGridColumn>
        <TreeGridColumn Field="Progress" HeaderText="Progress" Width="100" TextAlign="Syncfusion.Blazor.Grids.TextAlign.Right"></TreeGridColumn>
    </TreeGridColumns>
</SfTreeGrid>

@code{
    SfTreeGrid<TreeData> TreeGrid;

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

    protected override void OnInitialized()
    {
        this.TreeGridData = TreeData.GetSelfDataSource().ToList();
    }
    public void RowCreatingHandler(RowCreatingEventArgs<TreeData.BusinessObject> args)
    {
        args.Cancel = true;
    }
}

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> TreeDataCollection = new List<TreeData>();
            TreeDataCollection.Add(new TreeData() { TaskId = 1, TaskName = "Parent Task 1", Duration = 10, Progress = 70, Priority = "Critical", ParentId = null });
            TreeDataCollection.Add(new TreeData() { TaskId = 2, TaskName = "Child task 1", Progress = 80, Priority = "Low", Duration = 50, ParentId = 1 });
            TreeDataCollection.Add(new TreeData() { TaskId = 3, TaskName = "Child Task 2", Duration = 5, Progress = 65, Priority = "Critical", ParentId = 2 });
            TreeDataCollection.Add(new TreeData() { TaskId = 4, TaskName = "Child task 3", Duration = 6, Priority = "High", Progress = 77, ParentId = 3 });
            TreeDataCollection.Add(new TreeData() { TaskId = 5, TaskName = "Parent Task 2", Duration = 10, Progress = 70, Priority = "Critical", ParentId = null });
            TreeDataCollection.Add(new TreeData() { TaskId = 6, TaskName = "Child task 1", Duration = 4, Progress = 80, Priority = "Critical", ParentId = 5 });
            TreeDataCollection.Add(new TreeData() { TaskId = 7, TaskName = "Child Task 2", Duration = 5, Progress = 65, Priority = "Low", ParentId = 5 });
            TreeDataCollection.Add(new TreeData() { TaskId = 8, TaskName = "Child task 3", Duration = 6, Progress = 77, Priority = "High", ParentId = 5 });
            TreeDataCollection.Add(new TreeData() { TaskId = 9, TaskName = "Child task 4", Duration = 6, Progress = 77, Priority = "Low", ParentId = 5 });
            return TreeDataCollection;
        }
    }
}