UploadDataCompletedEventHandler 委托

定义

命名空间:

System.Net

程序集:

System.Net.WebClient.dll

表示将用来处理 UploadDataCompleted 的 WebClient 事件的方法。

public delegate void UploadDataCompletedEventHandler(System::Object ^ sender, UploadDataCompletedEventArgs ^ e);

public delegate void UploadDataCompletedEventHandler(object sender, UploadDataCompletedEventArgs e);

type UploadDataCompletedEventHandler = delegate of obj * UploadDataCompletedEventArgs -> unit

Public Delegate Sub UploadDataCompletedEventHandler(sender As Object, e As UploadDataCompletedEventArgs)

参数

sender

Object

事件源。

e

UploadDataCompletedEventArgs

一个包含事件数据的 UploadDataCompletedEventArgs。

示例

下面的代码示例演示如何异步上传数据。

void UploadDataInBackground2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);
   String^ text = "Time = 12:00am temperature = 50";
   array<Byte>^data = System::Text::Encoding::UTF8->GetBytes( text );
   String^ method = "POST";

   client->UploadDataCompleted += gcnew UploadDataCompletedEventHandler( UploadDataCallback2 );
   client->UploadDataAsync( uri, method, data );
}

public static void UploadDataInBackground2(string address)
{
    WebClient client = new WebClient();
    Uri uri = new Uri(address);
    string text = "Time = 12:00am temperature = 50";
    byte[] data = System.Text.Encoding.UTF8.GetBytes(text);
    string method = "POST";

    client.UploadDataCompleted += new UploadDataCompletedEventHandler(UploadDataCallback2);
    client.UploadDataAsync(uri, method, data);
}

Public Shared Sub UploadDataInBackground2(ByVal address As String)

    Dim client As WebClient = New WebClient()
    Dim text As String = "Time = 12:00am temperature = 50"
    Dim data() As Byte = System.Text.Encoding.UTF8.GetBytes(text)
    Dim method As String = "POST"

    AddHandler client.UploadDataCompleted, AddressOf UploadDataCallback2
    Dim uri as Uri = New Uri(address)
                client.UploadDataAsync(uri, method, data)
End Sub

上传完成后，将调用以下方法。

void UploadDataCallback2( Object^ /*sender*/, UploadDataCompletedEventArgs^ e )
{
   array<Byte>^data = dynamic_cast<array<Byte>^>(e->Result);
   String^ reply = System::Text::Encoding::UTF8->GetString( data );
   Console::WriteLine( reply );
}

private static void UploadDataCallback2(Object sender, UploadDataCompletedEventArgs e)
{
    byte[] data = (byte[])e.Result;
    string reply = System.Text.Encoding.UTF8.GetString(data);

    Console.WriteLine(reply);
}

Private Shared Sub UploadDataCallback2(ByVal sender As Object, ByVal e As UploadDataCompletedEventArgs)

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

    Console.WriteLine(reply)
End Sub

注解

创建 UploadDataCompletedEventHandler 委托时，需要标识将处理该事件的方法。 若要将事件与事件处理程序关联，请将该委托的一个实例添加到事件中。 除非移除了该委托，否则每当发生该事件时就会调用事件处理程序。 有关事件处理程序委托的详细信息，请参阅 处理和引发事件。

扩展方法

GetMethodInfo(Delegate)

获取指示指定委托表示的方法的对象。