WebClient.DownloadFileCompleted イベント

定義

非同期のファイル ダウンロード操作の完了時に発生します。Occurs when an asynchronous file download operation completes.

public:
 event System::ComponentModel::AsyncCompletedEventHandler ^ DownloadFileCompleted;
public event System.ComponentModel.AsyncCompletedEventHandler? DownloadFileCompleted;
public event System.ComponentModel.AsyncCompletedEventHandler DownloadFileCompleted;
member this.DownloadFileCompleted : System.ComponentModel.AsyncCompletedEventHandler 
Public Custom Event DownloadFileCompleted As AsyncCompletedEventHandler 
Public Event DownloadFileCompleted As AsyncCompletedEventHandler 

イベントの種類

AsyncCompletedEventHandler

次のコード例は、イベントのイベントハンドラーを設定する方法を示して DownloadFileCompleted います。The following code example demonstrates setting an event handler for the DownloadFileCompleted event.

// Sample call : DownLoadFileInBackground2 ("http://www.contoso.com/logs/January.txt");
void DownLoadFileInBackground2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);

   // Call DownloadFileCallback2 when the download completes.
   client->DownloadFileCompleted += gcnew AsyncCompletedEventHandler( DownloadFileCallback2 );

   // Specify a progress notification handler here...

   client->DownloadFileAsync( uri, "serverdata.txt" );
}

void DownloadFileCallback2( Object^ /*sender*/, System::ComponentModel::AsyncCompletedEventArgs^ e )
{
   if ( e->Cancelled )
   {
      Console::WriteLine( "File download cancelled." );
   }

   if ( e->Error != nullptr )
   {
      Console::WriteLine( e->Error->ToString() );
   }
}
// Sample call : DownLoadFileInBackground2 ("http://www.contoso.com/logs/January.txt");
public static void DownLoadFileInBackground2(string address)
{
    WebClient client = new WebClient();
    Uri uri = new Uri(address);

    // Call DownloadFileCallback2 when the download completes.
    client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadFileCallback2);

    // Specify a progress notification handler here ...

    client.DownloadFileAsync(uri, "serverdata.txt");
}

private static void DownloadFileCallback2(object sender, AsyncCompletedEventArgs e)
{
    if (e.Cancelled)
    {
        Console.WriteLine("File download cancelled.");
    }

    if (e.Error != null)
    {
        Console.WriteLine(e.Error.ToString());
    }
}
' Sample call : DownLoadFileInBackground2 ("http:' www.contoso.com/logs/January.txt")
Public Shared Sub DownLoadFileInBackground2(address As String)

    Dim client As WebClient = New WebClient()

    ' Call DownloadFileCallback2 when the download completes.
    AddHandler client.DownloadFileCompleted, AddressOf DownloadFileCallback2

    ' Specify a progress notification handler here...

    Dim uri as Uri = New Uri(address)
    client.DownloadFileAsync(uri, "serverdata.txt")
End Sub

Private Shared Sub DownloadFileCallback2(sender As Object, e As AsyncCompletedEventArgs)
    If e.Cancelled = True Then
        Console.WriteLine("File download cancelled.")
    End If

    If Not e.Error Is Nothing Then
        Console.WriteLine(e.Error.ToString())
    End If
End Sub

注釈

このイベントは、ファイルの非同期ダウンロード操作が完了するたびに発生します。This event is raised each time an asynchronous file download operation completes. 非同期ファイルダウンロードは、メソッドを呼び出すことによって開始され DownloadFileAsync ます。Asynchronous file downloads are started by calling the DownloadFileAsync methods.

は、 AsyncCompletedEventHandler このイベントのデリゲートです。The AsyncCompletedEventHandler is the delegate for this event. クラスは、イベント AsyncCompletedEventArgs データを含むイベントハンドラーを提供します。The AsyncCompletedEventArgs class provides the event handler with event data.

イベントを処理する方法の詳細については、次を参照してください。処理とイベントの発生します。For more information about how to handle events, see Handling and Raising Events.

適用対象