DxTreeList.AllowDragRows Property

Specifies whether users can start the row drag operation.

Assembly : DevExpress.Blazor.v25.2.dll

Declaration

csharp

[DefaultValue(false)]
[Parameter]
public bool AllowDragRows { get; set; }

Property Value

Type	Default	Description
Boolean	false

true to allow users to start dragging rows; otherwise, false.

Remarks

When you activate the AllowDragRows option, the TreeList component renders a drag handle for each data row:

The AllowedDropTarget property value specifies whether users can reorder rows or move them to other components. To update the data source, handle the target component’s ItemsDropped event.

The following example implements row reordering within a TreeList:

Run Demo: Drag and Drop Rows - Reorder

razor

<DxTreeList @ref="TreeList"
            Data="DataSource"
            KeyFieldName="Id"
            ParentKeyFieldName="ParentId"
            AllowDragRows="true"
            CssClass="max-h-480"
            ItemsDropped="TreeList_ItemsDropped">
    <Columns>
        <DxTreeListDataColumn FieldName="Name" Caption="Task" SortOrder="TreeListColumnSortOrder.Ascending" />
        <DxTreeListDataColumn FieldName="EmployeeName" Caption="Assigned To" TextAlignment="TreeListTextAlignment.Left" Width="200px" />
        <DxTreeListDataColumn FieldName="StartDate" Width="100px" />
        <DxTreeListDataColumn FieldName="DueDate" Width="100px" />
    </Columns>
</DxTreeList>

@code {
    ITreeList TreeList { get; set; }
    ObservableCollection<EmployeeTask> DataSource { get; set; }
    protected override void OnInitialized() {
        DataSource = new ObservableCollection<EmployeeTask>(EmployeeTaskDataProvider.GenerateData());
    }
    void TreeList_ItemsDropped(TreeListItemsDroppedEventArgs evt) {
        if(evt.TargetItem == null)
            return;
        var droppedTask = (EmployeeTask)evt.DroppedItems[0];
        DataSource.Remove(droppedTask);
        var targetTask = (EmployeeTask)evt.TargetItem;
        droppedTask.ParentId = evt.DropPosition == TreeListItemDropPosition.Inside
            ? targetTask.Id
            : targetTask.ParentId;
        var index = DataSource.IndexOf(targetTask) + (evt.DropPosition == TreeListItemDropPosition.After ? 1 : 0);
        DataSource.Insert(index, droppedTask);
    }
}

Implements

AllowDragRows