FtpWebRequest.GetRequestStream 方法

定义

命名空间:

System.Net

程序集:

System.Net.Requests.dll

Source:

FtpWebRequest.cs

检索用于向 FTP 服务器上载数据的流。

public:
 override System::IO::Stream ^ GetRequestStream();

public override System.IO.Stream GetRequestStream ();

override this.GetRequestStream : unit -> System.IO.Stream

Public Overrides Function GetRequestStream () As Stream

返回

Stream

可写 Stream 实例，用于存储要由当前请求发送到服务器的数据。

例外

InvalidOperationException

BeginGetRequestStream(AsyncCallback, Object) 已被调用并且尚未完成。

- 或 -

HTTP 代理被启用，而您尝试使用 FTP 命令而非 DownloadFile、ListDirectory 或 ListDirectoryDetails。

WebException

未能建立到 FTP 服务器的连接。

ProtocolViolationException

Method 属性未设置为 UploadFile 或 AppendFile。

示例

下面的代码示例演示如何将文件复制到请求的数据流，并将请求发送到服务器以上传数据并将其追加到文件。

static bool AppendFileOnServer( String^ fileName, Uri^ serverUri )
{
   // The URI described by serverUri should use the ftp:// scheme.
   // It contains the name of the file on the server.
   // Example: ftp://contoso.com/someFile.txt. 
   // The fileName parameter identifies the file containing 
   // the data to be appended to the file on the server.
   if ( serverUri->Scheme != Uri::UriSchemeFtp )
   {
      return false;
   }

   // Get the object used to communicate with the server.
   FtpWebRequest^ request = dynamic_cast<FtpWebRequest^>(WebRequest::Create( serverUri ));
   request->Method = WebRequestMethods::Ftp::AppendFile;
   StreamReader^ sourceStream = gcnew StreamReader( fileName );
   array<Byte>^fileContents = Encoding::UTF8->GetBytes( sourceStream->ReadToEnd() );
   sourceStream->Close();
   request->ContentLength = fileContents->Length;

   // This example assumes the FTP site uses anonymous logon.
   request->Credentials = gcnew NetworkCredential( "anonymous","janeDoe@contoso.com" );
   Stream^ requestStream = request->GetRequestStream();
   requestStream->Write( fileContents, 0, fileContents->Length );
   requestStream->Close();
   FtpWebResponse^ response = dynamic_cast<FtpWebResponse^>(request->GetResponse());
   Console::WriteLine( "Append status: {0}", response->StatusDescription );
   response->Close();
   return true;
}

public static bool AppendFileOnServer(string fileName, Uri serverUri)
{
    // The URI described by serverUri should use the ftp:// scheme.
    // It contains the name of the file on the server.
    // Example: ftp://contoso.com/someFile.txt.
    // The fileName parameter identifies the file containing
    // the data to be appended to the file on the server.

    if (serverUri.Scheme != Uri.UriSchemeFtp)
    {
        return false;
    }
    // Get the object used to communicate with the server.
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverUri);
    request.Method = WebRequestMethods.Ftp.AppendFile;

    StreamReader sourceStream = new StreamReader(fileName);
    byte [] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());
    sourceStream.Close();
    request.ContentLength = fileContents.Length;

    // This example assumes the FTP site uses anonymous logon.
    request.Credentials = new NetworkCredential ("anonymous","janeDoe@contoso.com");
    Stream requestStream = request.GetRequestStream();
    requestStream.Write(fileContents, 0, fileContents.Length);
    requestStream.Close();
    FtpWebResponse response = (FtpWebResponse) request.GetResponse();

    Console.WriteLine("Append status: {0}",response.StatusDescription);

    response.Close();
    return true;
}

注解

在调用 GetRequestStream 方法之前设置请求属性。 将数据写入流后，必须在发送请求之前关闭流。

如果尚未将 Method 属性设置为 UploadFile 或 AppendFile，则无法获取流。

GetRequestStream 在等待流时阻止。 若要防止出现这种情况，请 BeginGetRequestStream 调用 方法代替 GetRequestStream。

备注

当你在应用程序中启用网络跟踪后，此成员将输出跟踪信息。 有关详细信息，请参阅.NET Framework中的网络跟踪。

调用方说明

此方法生成网络流量。

另请参阅

• FtpWebResponse
• FtpStatusCode
• WebRequestMethods.Ftp
• WebRequest
• WebResponse
• WebClient