ChangingEventHandler Delegate

Represents a method that will handle the RepositoryItem.EditValueChanging event.

Namespace: DevExpress.XtraEditors.Controls

Assembly: DevExpress.XtraEditors.v24.2.dll

Declaration

C#

public delegate void ChangingEventHandler(
    object sender,
    ChangingEventArgs e
);

VB.NET

Public Delegate Sub ChangingEventHandler(
    sender As Object,
    e As ChangingEventArgs
)

Parameters

Name	Type	Description
sender	Object	The event sender (typically the BaseEdit descendant).
e	ChangingEventArgs	A ChangingEventArgs object containing data related to the event.

Remarks

When creating a ChangingEventHandler delegate, you identify the method that will handle the corresponding event. To associate an event with your event handler, add a delegate instance to this event. The event handler is called whenever the event occurs unless you remove the delegate.

The code sample below handles the TextEdit’s EditValueChanged event to accept only numeric values:

C#

textEdit1.EditValueChanging += TextEdit1_EditValueChanging;

void TextEdit1_EditValueChanging(object sender, DevExpress.XtraEditors.Controls.ChangingEventArgs e) {
    int i = 0;
    if (!int.TryParse(e.NewValue.ToString(), out i))
        e.Cancel = true;
}

VB.NET

Private textEdit1.EditValueChanging += AddressOf TextEdit1_EditValueChanging

Private Sub TextEdit1_EditValueChanging(ByVal sender As Object, ByVal e As DevExpress.XtraEditors.Controls.ChangingEventArgs)
    Dim value = e.NewValue.ToString()
    Dim i As Integer = 0
    If Not Integer.TryParse(value, i) Then
        e.Cancel = True
    End If
End Sub