FtpWebResponse.ContentLength Properti

Definisi

Ruang nama:

System.Net

Rakitan:

System.Net.Requests.dll

Sumber:

FtpWebResponse.cs

Mendapatkan panjang data yang diterima dari server FTP.

public:
 virtual property long ContentLength { long get(); };

public override long ContentLength { get; }

member this.ContentLength : int64

Public Overrides ReadOnly Property ContentLength As Long

Nilai Properti

Int64

Nilai Int64 yang berisi jumlah byte data yang diterima dari server FTP.

Contoh

Contoh kode berikut mengunduh file dari pada server FTP yang ditentukan. Properti ini berisi jumlah byte dalam file yang diunduh.

static bool DownloadFileFromServer( Uri^ serverUri, String^ localFileName )
{
   // The serverUri parameter should start with the ftp:// scheme.
   if ( serverUri->Scheme != Uri::UriSchemeFtp )
   {
      return false;
   }

   // Get the object used to communicate with the server.
   // Note that the cast to FtpWebRequest is done only
   // for the purposes of illustration. If your application
   // does not set any properties other than those defined in the
   // System.Net.WebRequest class, you can use the following line instead:
   // WebRequest request = WebRequest.Create(serverUri);
   //
   FtpWebRequest^ request = dynamic_cast<FtpWebRequest^>(WebRequest::Create( serverUri ));
   request->Method = WebRequestMethods::Ftp::DownloadFile;
   FtpWebResponse^ response = dynamic_cast<FtpWebResponse^>(request->GetResponse());
   Stream^ responseStream = nullptr;
   StreamReader^ readStream = nullptr;
   StreamWriter^ writeStream = nullptr;
   try
   {
      responseStream = response->GetResponseStream();
      readStream = gcnew StreamReader( responseStream,System::Text::Encoding::UTF8 );
      
      // Display information about the data received from the server.
      Console::WriteLine( "Bytes received: {0}", response->ContentLength );
      Console::WriteLine( "Message from server: {0}", response->StatusDescription );
      Console::WriteLine( "Resource: {0}", response->ResponseUri );

      // Write the bytes received from the server to the local file.
      if ( readStream != nullptr )
      {
         writeStream = gcnew StreamWriter( localFileName,false );
         writeStream->Write( readStream->ReadToEnd() );
      }
   }
   finally
   {
      if ( readStream != nullptr )
      {
         readStream->Close();
      }

      if ( response != nullptr )
      {
         response->Close();
      }

      if ( writeStream != nullptr )
      {
         writeStream->Close();
      }
   }

   return true;
}

public static bool DownloadFileFromServer(Uri serverUri, string localFileName)
{
    // The serverUri parameter should start with the ftp:// scheme.
    if (serverUri.Scheme != Uri.UriSchemeFtp)
    {
        return false;
    }
    // Get the object used to communicate with the server.
    // Note that the cast to FtpWebRequest is done only
    // for the purposes of illustration. If your application
    // does not set any properties other than those defined in the
    // System.Net.WebRequest class, you can use the following line instead:
    // WebRequest request = WebRequest.Create(serverUri);
    //
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverUri);
    request.Method = WebRequestMethods.Ftp.DownloadFile;

    FtpWebResponse response = (FtpWebResponse) request.GetResponse();

    Stream responseStream = null;
    StreamReader readStream = null;
    StreamWriter writeStream = null;
    try
    {
        responseStream = response.GetResponseStream();
        readStream = new StreamReader(responseStream, System.Text.Encoding.UTF8);
        // Display information about the data received from the server.
        Console.WriteLine("Bytes received: {0}",response.ContentLength);

        Console.WriteLine("Message from server: {0}", response.StatusDescription);
        Console.WriteLine("Resource: {0}", response.ResponseUri);

        // Write the bytes received from the server to the local file.
        if (readStream != null)
        {
            writeStream = new StreamWriter(localFileName, false);
            writeStream.Write(readStream.ReadToEnd());
        }
    }
    finally
    {
        if (readStream != null)
        {
            readStream.Close();
        }
        if (response != null)
        {
            response.Close();
        }
        if (writeStream != null)
        {
            writeStream.Close();
        }
    }
    return true;
}

Keterangan

Ketika aliran respons dikembalikan oleh server FTP, ContentLength properti berisi jumlah byte dalam aliran. ContentLength mengembalikan −1 jika tidak ada data yang dikembalikan dalam respons atau jika server tidak mengirim informasi panjang konten. Nilai yang dikembalikan lebih besar dari atau sama dengan nol jika data adalah atau seharusnya dikembalikan. Misalnya, untuk permintaan yang menggunakan ListDirectory bidang , ContentLength properti selalu mengembalikan −1. Untuk permintaan yang menggunakan UploadFile metode , ContentLength properti selalu nol. Untuk permintaan yang menggunakan DownloadFile metode , properti lebih besar dari nol jika file yang diunduh berisi data dan nol jika kosong.

Untuk permintaan yang menggunakan GetFileSize metode , ContentLength mengembalikan ukuran file yang ditentukan di server.

Lihat juga

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