Control.Invalidated Control.Invalidated Control.Invalidated Control.Invalidated Event

定義

發生於控制項的顯示需要重新繪製時。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;
member this.Invalidated : System.Windows.Forms.InvalidateEventHandler 
Public Custom Event Invalidated As InvalidateEventHandler 
屬性

範例

下列程式碼範例示範如何使用這個成員。The following code example demonstrates the use of this member. 在此範例中, 事件處理常式會報告Invalidated事件的發生次數。In the example, an event handler reports on the occurrence of the Invalidated event. 此報表可協助您瞭解事件發生的時間, 並可協助您進行調試。This report helps you to learn when the event occurs and can assist you in debugging. 若要報告多個事件或經常發生的事件, 請考慮MessageBox.ShowConsole.WriteLine取代為, 或將訊息附加TextBox至多行。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.

若要執行範例程式碼,請將它貼到包含繼承自Control之類型實例的專案中,例如ButtonComboBoxTo 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. 然後為實例Control1命名,並確定事件處理常式Invalidated與事件相關聯。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

備註

如需處理事件的詳細資訊, 請參閱處理和引發事件For more information about handling events, see Handling and Raising Events.

適用於

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