HttpWebRequest.EndGetRequestStream 方法
结束对用于写入数据的 Stream 对象的异步请求。
**命名空间:**System.Net
**程序集:**System（在 system.dll 中）
语法
声明
Public Overrides Function EndGetRequestStream ( _
asyncResult As IAsyncResult _
) As Stream
用法
Dim instance As HttpWebRequest
Dim asyncResult As IAsyncResult
Dim returnValue As Stream
returnValue = instance.EndGetRequestStream(asyncResult)
public override Stream EndGetRequestStream (
IAsyncResult asyncResult
)
public:
virtual Stream^ EndGetRequestStream (
IAsyncResult^ asyncResult
) override
public Stream EndGetRequestStream (
IAsyncResult asyncResult
)
public override function EndGetRequestStream (
asyncResult : IAsyncResult
) : Stream
参数
- asyncResult
流的待定的请求。
返回值
用来写入请求数据的 Stream。
异常
| 异常类型 | 条件 |
|---|---|
asyncResult 为 空引用（在 Visual Basic 中为 Nothing）。 |
|
请求未完成，没有可用的流。 |
|
当前实例没有从 BeginGetRequestStream 调用返回 asyncResult。 |
|
以前使用 asyncResult 调用过此方法。 |
|
Abort 以前被调用过。 - 或 - 处理请求时发生错误。 |
备注
EndGetRequestStream 方法完成对由 BeginGetRequestStream 方法开始的流的异步请求。返回 Stream 对象后，可以通过使用 Stream.Write 方法发送带有 HttpWebRequest 的数据。
提示
必须先设置 ContentLength 属性的值，然后才能将数据写入到该流。
警告
必须调用 Stream.Close 方法关闭该流并释放连接以便重新使用。关闭该流失败将导致应用程序用尽连接。
提示
当在应用程序中启用网络跟踪功能后，此成员将输出跟踪信息。有关更多信息，请参见 网络跟踪。
示例
下面的代码示例使用 EndGetRequestStream 方法来结束对流实例的异步请求。
Imports System
Imports System.Net
Imports System.IO
Imports System.Text
Imports System.Threading
Imports Microsoft.VisualBasic
Class HttpWebRequestBeginGetRequest
Public Shared allDone As New ManualResetEvent(False)
Shared Sub Main()
' Create a new HttpWebRequest object.
' Dim request As HttpWebRequest = CType(WebRequest.Create("https://www.contoso.com/example.aspx"), _
' HttpWebRequest)
Dim request As HttpWebRequest = CType(WebRequest.Create("https://localhost/test/PostAccepter.aspx"), _
HttpWebRequest)
' Set the ContentType property.
request.ContentType = "application/x-www-form-urlencoded"
' Set the Method property to 'POST' to post data to the URI.
request.Method = "POST"
' Start the asynchronous operation.
Dim result As IAsyncResult = _
CType(request.BeginGetRequestStream(AddressOf ReadCallback, request), IAsyncResult)
' Keep the main thread from continuing while the asynchronous
' operation completes. A real world application
' could do something useful such as updating its user interface.
allDone.WaitOne()
' Get the response.
Dim response As HttpWebResponse = CType(request.GetResponse(), HttpWebResponse)
Dim streamResponse As Stream = response.GetResponseStream()
Dim streamRead As New StreamReader(streamResponse)
Dim responseString As String = streamRead.ReadToEnd()
Console.WriteLine(responseString)
' Close Stream object.
streamResponse.Close()
streamRead.Close()
' Release the HttpWebResponse.
response.Close()
End Sub ' Main
Private Shared Sub ReadCallback(ByVal asynchronousResult As IAsyncResult)
Dim request As HttpWebRequest = CType(asynchronousResult.AsyncState, HttpWebRequest)
' End the operation.
Dim postStream As Stream = request.EndGetRequestStream(asynchronousResult)
Console.WriteLine("Please enter the input data to be posted:")
Dim postData As [String] = Console.ReadLine()
' Convert the string into byte array.
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
' Write to the stream.
postStream.Write(byteArray, 0, postData.Length)
postStream.Close()
allDone.Set()
End Sub ' ReadCallback
End Class ' HttpWebRequest_BeginGetRequest
using System;
using System.Net;
using System.IO;
using System.Text;
using System.Threading;
class HttpWebRequestBeginGetRequest
{
public static ManualResetEvent allDone = new ManualResetEvent(false);
public static void Main()
{
// Create a new HttpWebRequest object.
HttpWebRequest request=(HttpWebRequest) WebRequest.Create("https://www.contoso.com/example.aspx");
// Set the ContentType property.
request.ContentType="application/x-www-form-urlencoded";
// Set the Method property to 'POST' to post data to the URI.
request.Method = "POST";
// Start the asynchronous operation.
request.BeginGetRequestStream(new AsyncCallback(ReadCallback), request);
// Keep the main thread from continuing while the asynchronous
// operation completes. A real world application
// could do something useful such as updating its user interface.
allDone.WaitOne();
// Get the response.
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream streamResponse = response.GetResponseStream();
StreamReader streamRead = new StreamReader(streamResponse);
string responseString = streamRead.ReadToEnd();
Console.WriteLine(responseString);
// Close the stream object.
streamResponse.Close();
streamRead.Close();
// Release the HttpWebResponse.
response.Close();
}
private static void ReadCallback(IAsyncResult asynchronousResult)
{
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
// End the operation.
Stream postStream = request.EndGetRequestStream(asynchronousResult);
Console.WriteLine("Please enter the input data to be posted:");
string postData = Console.ReadLine ();
// Convert the string into a byte array.
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Write to the request stream.
postStream.Write(byteArray, 0, postData.Length);
postStream.Close ();
allDone.Set();
}
}
#using <System.dll>
using namespace System;
using namespace System::Net;
using namespace System::IO;
using namespace System::Text;
using namespace System::Threading;
ref class HttpWebRequestBeginGetRequest
{
public:
static ManualResetEvent^ allDone = gcnew ManualResetEvent( false );
static void Main()
{
// Create a new HttpWebRequest object.
HttpWebRequest^ request = dynamic_cast<HttpWebRequest^>(WebRequest::Create( "https://www.contoso.com/example.aspx" ));
// Set the ContentType property.
request->ContentType = "application/x-www-form-urlencoded";
// Set the Method property to 'POST' to post data to the Uri.
request->Method = "POST";
// Start the asynchronous operation.
AsyncCallback^ del = gcnew AsyncCallback( ReadCallback );
request->BeginGetRequestStream( del, request );
// Keep the main thread from continuing while the asynchronous
// operation completes. A real world application
// could do something useful such as updating its user interface.
allDone->WaitOne();
HttpWebResponse^ response = dynamic_cast<HttpWebResponse^>(request->GetResponse());
Stream^ streamResponse = response->GetResponseStream();
StreamReader^ streamRead = gcnew StreamReader( streamResponse );
String^ responseString = streamRead->ReadToEnd();
Console::WriteLine( responseString );
// Close Stream object.
streamResponse->Close();
streamRead->Close();
// Release the HttpWebResponse.
response->Close();
}
private:
static void ReadCallback( IAsyncResult^ asynchronousResult )
{
HttpWebRequest^ request = dynamic_cast<HttpWebRequest^>(asynchronousResult->AsyncState);
// End the operation.
Stream^ postStream = request->EndGetRequestStream( asynchronousResult );
Console::WriteLine( "Please enter the input data to be posted:" );
String^ postData = Console::ReadLine();
// Convert the string into Byte array.
array<Byte>^ByteArray = Encoding::UTF8->GetBytes( postData );
// Write to the request stream.
postStream->Write( ByteArray, 0, postData->Length );
postStream->Close();
allDone->Set();
}
};
void main()
{
HttpWebRequestBeginGetRequest::Main();
}
import System.*;
import System.Net.*;
import System.IO.*;
import System.Text.*;
import System.Threading.*;
class HttpWebRequestBeginGetRequest
{
public static ManualResetEvent allDone = new ManualResetEvent(false);
public static void main(String[] args)
{
// Create a new HttpWebRequest object.
HttpWebRequest request = (HttpWebRequest)(WebRequest.Create(
"https://www.contoso.com/example.aspx"));
// Set the ContentType property.
request.set_ContentType("application/x-www-form-urlencoded");
// Set the Method property to 'POST' to post data to the URI.
request.set_Method("POST");
// Start the asynchronous operation.
request.BeginGetRequestStream(new AsyncCallback(ReadCallback), request);
// Keep the main thread from continuing while the asynchronous
// operation completes. A real world application
// could do something useful such as updating its user interface.
allDone.WaitOne();
// Get the response.
HttpWebResponse response = (HttpWebResponse)(request.GetResponse());
Stream streamResponse = response.GetResponseStream();
StreamReader streamRead = new StreamReader(streamResponse);
String responseString = streamRead.ReadToEnd();
Console.WriteLine(responseString);
// Close the stream object.
streamResponse.Close();
streamRead.Close();
// Release the HttpWebResponse.
response.Close();
} //main
private static void ReadCallback(IAsyncResult asynchronousResult)
{
HttpWebRequest request = (HttpWebRequest)
(asynchronousResult.get_AsyncState());
// End the operation.
Stream postStream = request.EndGetRequestStream(asynchronousResult);
Console.WriteLine("Please enter the input data to be posted:");
String postData = Console.ReadLine();
// Convert the string into a byte array.
ubyte byteArray[] = Encoding.get_UTF8().GetBytes(postData);
// Write to the request stream.
postStream.Write(byteArray, 0, postData.get_Length());
postStream.Close();
allDone.Set();
} //ReadCallback
} //HttpWebRequestBeginGetRequest
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
.NET Compact Framework
受以下版本支持：2.0、1.0