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V24.2

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DxTreeListCommandColumn.NewButtonVisible Property

Specifies whether the command column displays New buttons.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

#Declaration

C#
[DefaultValue(true)]
[Parameter]
public bool NewButtonVisible { get; set; }

#Property Value

Type Default Description
Boolean true

true to display New buttons; otherwise, false.

#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.

Blazor TreeList Command Column

The New button in the command column header creates a new root node. New buttons in data row cells allow users to add children to the corresponding rows. Disable the NewButtonVisible property to hide all these buttons:

@inject EmployeeTaskService EmployeeTaskService

<DxTreeList Data="TreeListData"
            KeyFieldName="Id"
            ParentKeyFieldName="ParentId"
            EditModelSaving="TreeList_EditModelSaving"
            DataItemDeleting="TreeList_DataItemDeleting"
            CustomizeEditModel="TreeList_CustomizeEditModel">
    <Columns>
        <DxTreeListCommandColumn NewButtonVisible="false" DeleteButtonVisible="false" />
        <DxTreeListDataColumn FieldName="Name" Caption="Task" />
        <DxTreeListDataColumn FieldName="EmployeeName" />
        <DxTreeListDataColumn FieldName="StartDate" />
        <DxTreeListDataColumn FieldName="DueDate" />
    </Columns>
</DxTreeList>

@code {
    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);
    }
}

For information on how to enable data editing, refer to the following topic: Editing and Validation in Blazor TreeList.

See Also