TreeList.EditFormPrepared Event

Fires when the Edit Form is about to be displayed. Allows you to customize the Edit Form.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v19.2.dll

Declaration

C#

[DXCategory("Editor")]
public event EditFormPreparedEventHandler EditFormPrepared

VB.NET

<DXCategory("Editor")>
Public Event EditFormPrepared As EditFormPreparedEventHandler

Event Data

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

Property	Description
BindableControls	Provides access to the collection of controls used to edit the processed data record. Controls are indexed by field names or tree list nodes.
EditForm	Provides access to the Edit Form.
Node	Gets the processed node.
Panel	Gets the Edit Form’s root panel.

Example

The code below shows how to prevent the Edit Form from being shown in a particular case, focus an editor in the Edit Form, subscribe to the editor’s events, and get the clicked button when the Edit Form is closed.

C#

using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Controls;
using DevExpress.XtraTreeList;

// Prevents the Edit Form from being shown depending on the cell data.
private void treeList1_EditFormShowing(object sender, DevExpress.XtraTreeList.EditFormShowingEventArgs e) {
    if (e.Node.GetValue(colCity).Equals("Berlin"))
        e.Allow = false;
}
// Focuses the editor in the Edit Form that corresponds to the column focused in the Tree List.
// Subscribes to an editor's events.
private void treeList1_EditFormPrepared(object sender, DevExpress.XtraTreeList.EditFormPreparedEventArgs e) {
    TreeList treeList = sender as TreeList;
    Control editor = e.BindableControls[treeList.FocusedColumn];
    if (editor != null) {
        editor.Focus();
        ((IContainerControl)e.Panel).ActivateControl(editor);
    }

    TextEdit textEdit = e.BindableControls[colCity] as TextEdit;
    if (textEdit != null)
        textEdit.EditValueChanging += TextEdit_EditValueChanging;
}
private void TextEdit_EditValueChanging(object sender, ChangingEventArgs e) {
    // ...
}
// Unsubscribes from the editor's events.
// Shows a message depending on the clicked button.
private void treeList1_EditFormHidden(object sender, DevExpress.XtraTreeList.EditFormHiddenEventArgs e) {
   TextEdit textEdit = e.BindableControls[colCity] as TextEdit;
    if (textEdit != null)
        textEdit.EditValueChanging -= TextEdit_EditValueChanging;
    if (e.Result == EditFormResult.Update)
        XtraMessageBox.Show("Changes are successfully saved.");

}

VB.NET

Imports DevExpress.XtraEditors
Imports DevExpress.XtraEditors.Controls
Imports DevExpress.XtraTreeList

Private Sub treeList1_EditFormShowing(ByVal sender As Object, ByVal e As DevExpress.XtraTreeList.EditFormShowingEventArgs) _
    Handles treeList1.EditFormShowing
    If e.Node.GetValue(colCity).Equals("Berlin") Then
        e.Allow = False
    End If
End Sub
Private Sub treeList1_EditFormPrepared(ByVal sender As Object, ByVal e As DevExpress.XtraTreeList.EditFormPreparedEventArgs) _
    Handles treeList1.EditFormPrepared
    Dim treeList As TreeList = TryCast(sender, TreeList)
    Dim editor As Control = e.BindableControls(treeList.FocusedColumn)
    If editor IsNot Nothing Then
        editor.Focus()
        DirectCast(e.Panel, IContainerControl).ActivateControl(editor)
    End If

    Dim textEdit As TextEdit = TryCast(e.BindableControls(colCity), TextEdit)
    If textEdit IsNot Nothing Then
        AddHandler textEdit.EditValueChanging, AddressOf TextEdit_EditValueChanging
    End If
End Sub
Private Sub TextEdit_EditValueChanging(ByVal sender As Object, ByVal e As ChangingEventArgs)
    ' ...
End Sub
Private Sub treeList1_EditFormHidden(ByVal sender As Object, ByVal e As DevExpress.XtraTreeList.EditFormHiddenEventArgs) _
    Handles treeList1.EditFormHidden
    Dim textEdit As TextEdit = TryCast(e.BindableControls(colCity), TextEdit)
    If textEdit IsNot Nothing Then
        RemoveHandler textEdit.EditValueChanging, AddressOf TextEdit_EditValueChanging
    End If
    If e.Result = EditFormResult.Update Then
        XtraMessageBox.Show("Changes are successfully saved.")
    End If
End Sub