DownloadDataCompletedEventArgs.Result 属性

定义

获取由 DownloadDataAsync 方法下载的数据。Gets the data that is downloaded by a DownloadDataAsync method.

public:
 property cli::array <System::Byte> ^ Result { cli::array <System::Byte> ^ get(); };
public byte[] Result { get; }
member this.Result : byte[]
Public ReadOnly Property Result As Byte()

属性值

Byte[]

包含已下载数据的 Byte 数组。A Byte array that contains the downloaded data.

示例

下面的代码示例显示此属性的值。The following code example displays the value of this property.

void DownloadDataCallback( Object^ /*sender*/, DownloadDataCompletedEventArgs^ e )
{
   System::Threading::AutoResetEvent^ waiter = dynamic_cast<System::Threading::AutoResetEvent^>(e->UserState);
   try
   {
      
      // If the request was not canceled and did not throw
      // an exception, display the resource.
      if (  !e->Cancelled && e->Error == nullptr )
      {
         array<Byte>^data = dynamic_cast<array<Byte>^>(e->Result);
         String^ textData = System::Text::Encoding::UTF8->GetString( data );
         Console::WriteLine( textData );
      }
   }
   finally
   {
      
      // Let the main application thread resume.
      waiter->Set();
   }

}


private static void DownloadDataCallback (Object sender, DownloadDataCompletedEventArgs e)
{
    System.Threading.AutoResetEvent waiter = (System.Threading.AutoResetEvent)e.UserState;

    try
    {
        // If the request was not canceled and did not throw
        // an exception, display the resource.
        if (!e.Cancelled && e.Error == null)
        {
            byte[] data = (byte[])e.Result;
            string textData = System.Text.Encoding.UTF8.GetString (data);

            Console.WriteLine (textData);
        }
    }
    finally
    {
        // Let the main application thread resume.
        waiter.Set ();
    }
}

Private Shared Sub DownloadDataCallback(ByVal sender As Object, ByVal e As DownloadDataCompletedEventArgs)

    Dim waiter As System.Threading.AutoResetEvent = CType(e.UserState, System.Threading.AutoResetEvent)

    Try

        '  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 data() As Byte = CType(e.Result, Byte())
            Dim textData As String = System.Text.Encoding.UTF8.GetString(data)

            Console.WriteLine(textData)
        End If
    Finally

        '  Let the main application thread resume.
        waiter.Set()
    End Try
End Sub

注解

使用此属性返回的数据之前,应检查 ErrorCancelled 属性。You should check the Error and Cancelled properties before using the data that is returned by this property. 如果 Error 属性的值是一个 Exception 对象或 Cancelled 属性的值为 true,则异步操作未正确完成并且 Result 属性的值将无效。If the Error property's value is an Exception object or the Cancelled property's value is true, the asynchronous operation did not complete correctly and the Result property's value will not be valid.

适用于