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ITreeListSelectionColumn Interface

An interface that defines a TreeList selection column‘s API members (properties and methods).

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

#Declaration

C#
public interface ITreeListSelectionColumn :
    ITreeListColumn

#Remarks

Use the ITreeListSelectionColumn interface when you access a TreeList selection column’s API members as follows:

  • You use the @ref attribute to reference a TreeList selection column.
  • You access a SelectionColumn object from templates or event handlers.
  • You access elements of the TreeList column collection (for instance, the collection that the GetColumns() method returns).

In other cases, bind your data to column parameters.

Note

To change values of a TreeList selection column’s parameters outside the component’s markup, enclose your code between BeginUpdate() and EndUpdate() method calls. Otherwise, an exception occurs.

The following code snippet displays a button that changes the selection column’s visibility:

@inject EmployeeTaskService EmployeeTaskService

<style>
    .my-button {
        width: 300px;
    }
</style>

<DxTreeList @ref="MyTreeList"
            Data="TreeListData"
            KeyFieldName="Id"
            ParentKeyFieldName="ParentId">
    <Columns>
        <DxTreeListSelectionColumn @ref="SelectionColumn" />
        <DxTreeListDataColumn FieldName="Name" Caption="Task" />
        <DxTreeListDataColumn FieldName="EmployeeName" />
        <DxTreeListDataColumn FieldName="StartDate" />
        <DxTreeListDataColumn FieldName="DueDate" />
    </Columns>
</DxTreeList>

<DxButton Text="Show/Hide the Selection Column" Click="OnButtonClick" CssClass="my-button" />

@code {
    ITreeList MyTreeList { get; set; }
    ITreeListSelectionColumn SelectionColumn { get; set; }
    List<EmployeeTask> TreeListData { get; set; }

    protected override void OnInitialized() {
        TreeListData = EmployeeTaskService.GenerateData();
    }
    void OnButtonClick() {
        MyTreeList.BeginUpdate();
        SelectionColumn.Visible = !SelectionColumn.Visible;
        MyTreeList.EndUpdate();
    }
}

See Also