ASPxTreeList.CommandColumnButtonInitialize Event

Enables individual command buttons to be initialized.

Namespace: DevExpress.Web.ASPxTreeList

Assembly: DevExpress.Web.ASPxTreeList.v24.1.dll

NuGet Package: DevExpress.Web

Declaration

C#

public event TreeListCommandColumnButtonEventHandler CommandColumnButtonInitialize

VB.NET

Public Event CommandColumnButtonInitialize As TreeListCommandColumnButtonEventHandler

Event Data

The CommandColumnButtonInitialize event's data class is TreeListCommandColumnButtonEventArgs. The following properties provide information specific to this event:

Property	Description
ButtonType	Gets the type of the command button currently being initialized.
CommandColumn	Gets a command column which owns the processed command button.
CustomButtonIndex	Gets the processed command button’s index.
Enabled	Gets or sets whether the processed command button is enabled.
NodeKey	Gets the key of a node which contains the processed command button.
Visible	Gets or sets whether the command button is visible.

The event data class exposes the following methods:

Method	Description
GetValue(String)	Returns the value of the specified cell within the processed node.

Remarks

The CommandColumnButtonInitialize event is raised for each command button (edit, new, delete, etc.), and allows their settings to be initialized. For instance, you can hide or disable individual command buttons.

Example

This example illustrates how to hide the delete button for those nodes that have child nodes in the CommandColumnButtonInitialize event handler.

Default.aspx

<dx:ASPxTreeList ID="ASPxTreeList1" runat="server" AutoGenerateColumns="False" 
                 DataSourceID="AccessDataSource1" KeyFieldName="EmployeeID" 
                 ParentFieldName="ReportsTo" EnableCallbacks="true" 
                 OnCommandColumnButtonInitialize="ASPxTreeList1_CommandColumnButtonInitialize" 
                 OnNodeDeleting="ASPxTreeList1_NodeDeleting">
    <Columns>
        <dx:TreeListTextColumn FieldName="LastName" />
        <dx:TreeListTextColumn FieldName="FirstName" />
        <dx:TreeListTextColumn FieldName="Title" />
        <dx:TreeListCommandColumn >
            <DeleteButton Visible="True" />
        </dx:TreeListCommandColumn>
    </Columns>
</dx:ASPxTreeList>

Default.aspx.cs

protected void ASPxTreeList1_NodeDeleting (object sender, DevExpress.Web.Data.ASPxDataDeletingEventArgs e) {
    throw new Exception("Data modifications are not allowed in the online example.");
}
protected void ASPxTreeList1_CommandColumnButtonInitialize (object sender, TreeListCommandColumnButtonEventArgs e) {
    if (e.ButtonType != TreeListCommandColumnButtonType.Delete)
        return;
    if (ASPxTreeList1.FindNodeByKeyValue(e.NodeKey).ChildNodes.Count != 0)
        e.Visible = DevExpress.Utils.DefaultBoolean.False;
}

Default.aspx.vb

Protected Sub ASPxTreeList1_NodeDeleting(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataDeletingEventArgs)
    Throw New Exception("Data modifications are not allowed in the online example.")
End Sub
Protected Sub ASPxTreeList1_CommandColumnButtonInitialize(ByVal sender As Object, ByVal e As TreeListCommandColumnButtonEventArgs)
    If e.ButtonType <> TreeListCommandColumnButtonType.Delete Then
        Return
    End If

    If ASPxTreeList1.FindNodeByKeyValue(e.NodeKey).ChildNodes.Count <> 0 Then
        e.Visible = DevExpress.Utils.DefaultBoolean.False
    End If
End Sub