DxTreeListCommandColumn.HeaderTemplate Property
Specifies a template used to display the command column header.
Namespace: DevExpress.Blazor
Assembly: DevExpress.Blazor.v24.2.dll
NuGet Package: DevExpress.Blazor
Declaration
[Parameter]
public RenderFragment<TreeListCommandColumnHeaderTemplateContext> HeaderTemplate { get; set; }
Property Value
Type | Description |
---|---|
RenderFragment<TreeListCommandColumnHeaderTemplateContext> | A template for the command column header. |
Remarks
The command column displays predefined New, Edit, and Delete buttons for data rows in display mode. In EditRow
and EditCell
edit modes, this column displays Save and Cancel buttons for the edited row. In the filter row, the column displays the Clear button.
Define the HeaderTemplate
to display custom content in the command column header. Use the template’s context
parameter to access the CommandColumn object. The TreeList object allows you to access the component and call edit-related methods. For instance, call the StartEditNewRowAsync method to start editing a new data row.
Specify the CellDisplayTemplate to display custom command elements for cells in display mode. The CellEditTemplate allows you to display custom command elements for cells in edit mode. To display custom content in the filter row, define the FilterRowCellTemplate.
Note
Add, Edit, and Delete operations can be temporarily unavailable if you bind the TreeList to the GridDevExtremeDataSource or load data on demand. Use the following template parameters to specify the enabled or disabled state for custom command elements:
The following code snippet displays icons instead of default command buttons:
@inject EmployeeTaskService EmployeeTaskService
<DxTreeList @ref="MyTreeList"
Data="TreeListData"
KeyFieldName="Id"
ParentKeyFieldName="ParentId"
EditMode="TreeListEditMode.EditForm"
EditModelSaving="TreeList_EditModelSaving"
DataItemDeleting="TreeList_DataItemDeleting"
CustomizeEditModel="TreeList_CustomizeEditModel">
<Columns>
<DxTreeListCommandColumn Width="90px">
<HeaderTemplate>
<a class="oi oi-plus" @onclick="@(() => MyTreeList.StartEditNewRowAsync())" style="text-decoration: none;" href="javascript:void(0);"></a>
</HeaderTemplate>
<CellDisplayTemplate>
<a class="oi oi-pencil" @onclick="@(() => MyTreeList.StartEditRowAsync(context.VisibleIndex))" style="text-decoration: none;" href="javascript:void(0);"></a>
<a class="oi oi-plus" @onclick="@(() => MyTreeList.StartEditNewRowAsync(context.VisibleIndex))" style="text-decoration: none;" href="javascript:void(0);"></a>
<a class="oi oi-x" @onclick="@(() => MyTreeList.ShowRowDeleteConfirmation(context.VisibleIndex))" style="text-decoration: none;" href="javascript:void(0);"></a>
</CellDisplayTemplate>
</DxTreeListCommandColumn>
<DxTreeListDataColumn FieldName="Name" Caption="Task" />
<DxTreeListDataColumn FieldName="EmployeeName" />
<DxTreeListDataColumn FieldName="StartDate" />
<DxTreeListDataColumn FieldName="DueDate" />
</Columns>
<EditFormTemplate Context="EditFormContext">
<DxFormLayout CssClass="w-100">
<DxFormLayoutItem Caption="Task:" ColSpanMd="6">
@EditFormContext.GetEditor("Name")
</DxFormLayoutItem>
<DxFormLayoutItem Caption="Employee Name:" ColSpanMd="6">
@EditFormContext.GetEditor("EmployeeName")
</DxFormLayoutItem>
<DxFormLayoutItem Caption="Start Date:" ColSpanMd="6">
@EditFormContext.GetEditor("StartDate")
</DxFormLayoutItem>
<DxFormLayoutItem Caption="Due Date:" ColSpanMd="6">
@EditFormContext.GetEditor("DueDate")
</DxFormLayoutItem>
</DxFormLayout>
</EditFormTemplate>
</DxTreeList>
@code {
ITreeList MyTreeList { get; set; }
List<EmployeeTask> TreeListData { get; set; }
protected override void OnInitialized() {
TreeListData = EmployeeTaskService.GenerateData();
}
void TreeList_CustomizeEditModel(TreeListCustomizeEditModelEventArgs e) {
if (e.IsNew) {
var newTask = (EmployeeTask)e.EditModel;
newTask.Id = TreeListData.Max(x => x.Id) + 1;
if (e.ParentDataItem != null) {
newTask.ParentId = ((EmployeeTask)e.ParentDataItem).Id;
}
}
}
async Task TreeList_EditModelSaving(TreeListEditModelSavingEventArgs e) {
if (e.IsNew)
TreeListData.Add((EmployeeTask)e.EditModel);
else
e.CopyChangesToDataItem();
}
async Task TreeList_DataItemDeleting(TreeListDataItemDeletingEventArgs e) {
TreeListData.Remove((EmployeeTask)e.DataItem);
}
}