ASPxTreeList.CommandColumnButtonInitialize Event

Enables individual command buttons to be initialized.

Namespace: DevExpress.Web.ASPxTreeList

Assembly: DevExpress.Web.ASPxTreeList.v19.1.dll

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.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/aspxtreelist-how-to-hide-the-delete-button-for-nodes-that-have-child-nodes-e3567

Default.aspx (C#)

<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" VisibleIndex="0">
        </dx:TreeListTextColumn>
        <dx:TreeListTextColumn FieldName="FirstName" VisibleIndex="1">
        </dx:TreeListTextColumn>
        <dx:TreeListTextColumn FieldName="Title" VisibleIndex="2">
        </dx:TreeListTextColumn>
        <dx:TreeListCommandColumn VisibleIndex="3">
            <DeleteButton Visible="True">
            </DeleteButton>
        </dx:TreeListCommandColumn>
    </Columns>
    </dx:ASPxTreeList>
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/App_Data/nwind.mdb"
    DeleteCommand="DELETE FROM [Employees] WHERE [EmployeeID] = ?" InsertCommand="INSERT INTO [Employees] ([EmployeeID], [LastName], [FirstName], [Title], [ReportsTo]) VALUES (?, ?, ?, ?, ?)"
    SelectCommand="SELECT [EmployeeID], [LastName], [FirstName], [Title], [ReportsTo] FROM [Employees]"
    UpdateCommand="UPDATE [Employees] SET [LastName] = ?, [FirstName] = ?, [Title] = ?, [ReportsTo] = ? WHERE [EmployeeID] = ?">
    <DeleteParameters>
        <asp:Parameter Name="EmployeeID" Type="Int32" />
    </DeleteParameters>
    <UpdateParameters>
        <asp:Parameter Name="LastName" Type="String" />
        <asp:Parameter Name="FirstName" Type="String" />
        <asp:Parameter Name="Title" Type="String" />
        <asp:Parameter Name="ReportsTo" Type="Int32" />
        <asp:Parameter Name="EmployeeID" Type="Int32" />
    </UpdateParameters>
    <InsertParameters>
        <asp:Parameter Name="EmployeeID" Type="Int32" />
        <asp:Parameter Name="LastName" Type="String" />
        <asp:Parameter Name="FirstName" Type="String" />
        <asp:Parameter Name="Title" Type="String" />
        <asp:Parameter Name="ReportsTo" Type="Int32" />
    </InsertParameters>
</asp:AccessDataSource>

Default.aspx.cs

using DevExpress.Web.ASPxTreeList;

public partial class _Default : System.Web.UI.Page {
    protected void Page_Load (object sender, EventArgs e) {

    }
    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

Imports DevExpress.Web.ASPxTreeList

Partial Public Class _Default
    Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    End Sub
    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
End Class

Default.aspx (VB.NET)

<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" VisibleIndex="0">
        </dx:TreeListTextColumn>
        <dx:TreeListTextColumn FieldName="FirstName" VisibleIndex="1">
        </dx:TreeListTextColumn>
        <dx:TreeListTextColumn FieldName="Title" VisibleIndex="2">
        </dx:TreeListTextColumn>
        <dx:TreeListCommandColumn VisibleIndex="3">
            <DeleteButton Visible="True">
            </DeleteButton>
        </dx:TreeListCommandColumn>
    </Columns>
    </dx:ASPxTreeList>
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/App_Data/nwind.mdb"
    DeleteCommand="DELETE FROM [Employees] WHERE [EmployeeID] = ?" InsertCommand="INSERT INTO [Employees] ([EmployeeID], [LastName], [FirstName], [Title], [ReportsTo]) VALUES (?, ?, ?, ?, ?)"
    SelectCommand="SELECT [EmployeeID], [LastName], [FirstName], [Title], [ReportsTo] FROM [Employees]"
    UpdateCommand="UPDATE [Employees] SET [LastName] = ?, [FirstName] = ?, [Title] = ?, [ReportsTo] = ? WHERE [EmployeeID] = ?">
    <DeleteParameters>
        <asp:Parameter Name="EmployeeID" Type="Int32" />
    </DeleteParameters>
    <UpdateParameters>
        <asp:Parameter Name="LastName" Type="String" />
        <asp:Parameter Name="FirstName" Type="String" />
        <asp:Parameter Name="Title" Type="String" />
        <asp:Parameter Name="ReportsTo" Type="Int32" />
        <asp:Parameter Name="EmployeeID" Type="Int32" />
    </UpdateParameters>
    <InsertParameters>
        <asp:Parameter Name="EmployeeID" Type="Int32" />
        <asp:Parameter Name="LastName" Type="String" />
        <asp:Parameter Name="FirstName" Type="String" />
        <asp:Parameter Name="Title" Type="String" />
        <asp:Parameter Name="ReportsTo" Type="Int32" />
    </InsertParameters>
</asp:AccessDataSource>

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the CommandColumnButtonInitialize event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

XAF_how-to-enable-in-place-editing-in-the-aspnet-tree-list-view-aspxtreelisteditor-e3570/CS/WebExample.Module.Web/TreeListInlineEditController.cs#L22

editor.TreeList.NodeUpdating += new DevExpress.Web.Data.ASPxDataUpdatingEventHandler(TreeList_NodeUpdating);
editor.TreeList.CommandColumnButtonInitialize += new TreeListCommandColumnButtonEventHandler(TreeList_CommandColumnButtonInitialize);
foreach (TreeListColumn column in editor.TreeList.Columns) {

VB.NET

XAF_how-to-enable-in-place-editing-in-the-aspnet-tree-list-view-aspxtreelisteditor-e3570/VB/WebExample.Module.Web/TreeListInlineEditController.vb#L24

AddHandler editor.TreeList.NodeUpdating, AddressOf TreeList_NodeUpdating
AddHandler editor.TreeList.CommandColumnButtonInitialize, AddressOf TreeList_CommandColumnButtonInitialize
For Each column As TreeListColumn In editor.TreeList.Columns