DownloadStringCompletedEventArgs 类

定义

DownloadStringCompleted 事件提供数据。Provides data for the DownloadStringCompleted event.

public ref class DownloadStringCompletedEventArgs : System::ComponentModel::AsyncCompletedEventArgs
public class DownloadStringCompletedEventArgs : System.ComponentModel.AsyncCompletedEventArgs
type DownloadStringCompletedEventArgs = class
    inherit AsyncCompletedEventArgs
Public Class DownloadStringCompletedEventArgs
Inherits AsyncCompletedEventArgs
继承
DownloadStringCompletedEventArgs

示例

下面的代码示例演示如何以异步方式下载字符串。The following code example demonstrates downloading a string asynchronously.

// 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

下载完成时,将调用以下方法。The following method is called when the download completes.

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

注解

此类的实例将传递到 DownloadStringCompletedEventHandlerInstances of this class are passed to the DownloadStringCompletedEventHandler.

属性

Cancelled

获取一个值,该值指示异步操作是否已被取消。Gets a value indicating whether an asynchronous operation has been canceled.

(继承自 AsyncCompletedEventArgs)
Error

获取一个值,该值指示异步操作期间发生的错误。Gets a value indicating which error occurred during an asynchronous operation.

(继承自 AsyncCompletedEventArgs)
Result

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

UserState

获取异步任务的唯一标识符。Gets the unique identifier for the asynchronous task.

(继承自 AsyncCompletedEventArgs)

方法

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
RaiseExceptionIfNecessary()

如果异步操作失败,则引发用户提供的异常。Raises a user-supplied exception if an asynchronous operation failed.

(继承自 AsyncCompletedEventArgs)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(继承自 Object)

适用于