WebClient.DownloadStringCompleted Událost

Definice

Obor názvů:

System.Net

Sestavení:

System.Net.WebClient.dll

Zdroj:

WebClient.cs

Nastane, když se dokončí asynchronní operace stahování prostředků.

public:
 event System::Net::DownloadStringCompletedEventHandler ^ DownloadStringCompleted;

public event System.Net.DownloadStringCompletedEventHandler? DownloadStringCompleted;

member this.DownloadStringCompleted : System.Net.DownloadStringCompletedEventHandler 

Public Custom Event DownloadStringCompleted As DownloadStringCompletedEventHandler 

Event Type

DownloadStringCompletedEventHandler

Příklady

Následující příklad kódu ukazuje nastavení obslužné rutiny události pro tuto událost.

// Sample call : DownloadStringInBackground2 ("http://www.contoso.com/GameScores.html");
void DownloadStringInBackground2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);

   // Specify that the DownloadStringCallback2 method gets called
   // when the download completes.
   client->DownloadStringCompleted += gcnew DownloadStringCompletedEventHandler( DownloadStringCallback2 );
   client->DownloadStringAsync( uri );
}

// Sample call : DownloadStringInBackground2 ("http://www.contoso.com/GameScores.html");
public static void DownloadStringInBackground2(string address)
{
    WebClient client = new WebClient();
    Uri uri = new Uri(address);

    // Specify that the DownloadStringCallback2 method gets called
    // when the download completes.
    client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(DownloadStringCallback2);
    client.DownloadStringAsync(uri);
}

'  Sample call : DownloadStringInBackground2 ("http:' www.contoso.com/GameScores.html")
Public Shared Sub DownloadStringInBackground2(ByVal address As String)

    Dim client As WebClient = New WebClient()

    '  Specify that the DownloadStringCallback2 method gets called
    '  when the download completes.
    AddHandler client.DownloadStringCompleted, AddressOf DownloadStringCallback2
                Dim uri as Uri = New Uri(address)
    client.DownloadStringAsync(uri)
End Sub

Následující příklad kódu ukazuje implementaci obslužné rutiny pro tuto událost.

void DownloadStringCallback2( Object^ /*sender*/, DownloadStringCompletedEventArgs^ e )
{

   // If the request was not canceled and did not throw
   // an exception, display the resource.
   if (  !e->Cancelled && e->Error == nullptr )
   {
      String^ textString = dynamic_cast<String^>(e->Result);
      Console::WriteLine( textString );
   }
}

private static void DownloadStringCallback2(Object sender, DownloadStringCompletedEventArgs e)
{
    // If the request was not canceled and did not throw
    // an exception, display the resource.
    if (!e.Cancelled && e.Error == null)
    {
        string textString = (string)e.Result;

        Console.WriteLine(textString);
    }
}

Private Shared Sub DownloadStringCallback2(ByVal sender As Object, ByVal e As DownloadStringCompletedEventArgs)

    '  If the request was not canceled and did not throw
    '  an exception, display the resource.
    If e.Cancelled = False AndAlso e.Error Is Nothing Then

        Dim textString As String = CStr(e.Result)
        Console.WriteLine(textString)
    End If
End Sub

Poznámky

Opatrnost

WebRequest, HttpWebRequest, ServicePointa WebClient jsou zastaralé a neměli byste je používat pro nový vývoj. Místo toho použijte HttpClient.

Tato událost se vyvolá pokaždé, když asynchronní operace stáhne prostředek jako řetězec. Tyto operace se spouští voláním metod DownloadStringAsync.

DownloadStringCompletedEventHandler je delegátem této události. Třída DownloadStringCompletedEventArgs poskytuje obslužnou rutinu události s daty události.

Další informace o zpracování událostí naleznete v tématu zpracování a vyvolávání událostí.