Control.Invalidated Event
Definition
Important
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Occurs when a control's display requires redrawing.
public:
event System::Windows::Forms::InvalidateEventHandler ^ Invalidated;[System.ComponentModel.Browsable(false)]
public event System.Windows.Forms.InvalidateEventHandler Invalidated;[System.ComponentModel.Browsable(false)]
public event System.Windows.Forms.InvalidateEventHandler? Invalidated;[<System.ComponentModel.Browsable(false)>]
member this.Invalidated : System.Windows.Forms.InvalidateEventHandler Public Custom Event Invalidated As InvalidateEventHandler Event Type
- Attributes
Examples
The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the Invalidated event. This report helps you to learn when the event occurs and can assist you in debugging. To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.
To run the example code, paste it into a project that contains an instance of a type that inherits from Control, such as a Button or ComboBox. Then name the instance Control1 and ensure that the event handler is associated with the Invalidated event.
private void Control1_Invalidated(Object sender, InvalidateEventArgs e) {
System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "InvalidRect", e.InvalidRect );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "Invalidated Event" );
}
Private Sub Control1_Invalidated(sender as Object, e as InvalidateEventArgs) _
Handles Control1.Invalidated
Dim messageBoxVB as New System.Text.StringBuilder()
messageBoxVB.AppendFormat("{0} = {1}", "InvalidRect", e.InvalidRect)
messageBoxVB.AppendLine()
MessageBox.Show(messageBoxVB.ToString(),"Invalidated Event")
End Sub
Remarks
For more information about handling events, see Handling and Raising Events.
