WebClient.OnDownloadDataCompleted(DownloadDataCompletedEventArgs) 方法

定義

命名空間:

System.Net

組件:

System.Net.WebClient.dll

來源:

WebClient.cs

引發 DownloadDataCompleted 事件。

protected:
 virtual void OnDownloadDataCompleted(System::Net::DownloadDataCompletedEventArgs ^ e);

protected virtual void OnDownloadDataCompleted (System.Net.DownloadDataCompletedEventArgs e);

abstract member OnDownloadDataCompleted : System.Net.DownloadDataCompletedEventArgs -> unit
override this.OnDownloadDataCompleted : System.Net.DownloadDataCompletedEventArgs -> unit

Protected Overridable Sub OnDownloadDataCompleted (e As DownloadDataCompletedEventArgs)

參數

e

DownloadDataCompletedEventArgs

包含事件數據的 DownloadDataCompletedEventArgs 物件。

範例

下列程式代碼範例示範這個方法的實作，這個方法可由衍生自 WebClient的類別自定義。

virtual void OnDownloadDataCompleted( DownloadDataCompletedEventArgs ^ e ) override
{
   // Here you can perform any custom actions before the event is raised
   // and event handlers are called...
   WebClient::OnDownloadDataCompleted( e );

   // Here you can perform any post event actions...
}

protected override void OnDownloadDataCompleted (DownloadDataCompletedEventArgs e)
{
    // Here you can perform any custom actions before the event is raised
    // and event handlers are called...

    base.OnDownloadDataCompleted(e);

    // Here you can perform any post event actions...
}

備註

謹慎

WebRequest、HttpWebRequest、ServicePoint和 WebClient 已經過時，您不應該將它們用於新的開發。 請改用 HttpClient。

繼承自這個類別的類別可以覆寫此方法，以在發生 DownloadDataCompleted 事件時執行其他工作。

引發事件會透過委派叫用事件處理程式。 如需詳細資訊，請參閱 處理和引發事件。

OnDownloadDataCompleted 方法也允許衍生類別處理事件，而不附加委派。 這是在衍生類別中處理事件的慣用技術。

給繼承者的注意事項

在衍生類別中覆寫 OnDownloadDataCompleted(DownloadDataCompletedEventArgs) 時，請務必呼叫基類的 OnDownloadDataCompleted(DownloadDataCompletedEventArgs) 方法，讓已註冊的委派接收事件。