只顯示圖片的一小部分

Question

我寫了一個由服務器和客戶端組成的程序。服務器製作屏幕截圖桌面，客戶端收到屏幕截圖並在表單上顯示。數據傳輸有問題，我只看到一條小條。我檢查之前發送服務器上的圖像是好的。但是，客戶收到錯誤的圖像。哪裏不對？ XAML：

<Window x:Class="TestTCP.MainWindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="TestTCP" Height="350" Width="525"> 
<Grid> 
    <Image x:Name="img1" Margin="0"/> 

</Grid> 
</Window> 

代碼C＃：

public partial class MainWindow : Window 
    { 
    public MainWindow() 
    { 
     InitializeComponent(); 

     Task rec = new Task(WaitClientQuery); 
     rec.Start(); 

     Task tk = new Task(Send); 
     tk.Start(); 
    } 

    private void Send()//server part. take screen and send image 
    { 
     Bitmap temp = CaptureScreen(true); 
     MemoryStream ms3 = new MemoryStream(); 
     BitmapImage image = new BitmapImage(); 
     byte[] img_byte; 
     try 
     { 
      ((System.Drawing.Bitmap)temp).Save(ms3, System.Drawing.Imaging.ImageFormat.Bmp); 
      image.BeginInit(); 
      ms3.Seek(0, SeekOrigin.Begin); 
      image.StreamSource = ms3; 
      image.EndInit(); 

      JpegBitmapEncoder encoder = new JpegBitmapEncoder(); 
      encoder.Frames.Add(BitmapFrame.Create(image)); 
      using (MemoryStream ms = new MemoryStream()) 
      { 
       encoder.Save(ms); 
       img_byte = ms.ToArray(); 
      } 

      try 
      { 

       TcpClient client = new TcpClient("192.168.1.64", 4444); 
       NetworkStream netstream = client.GetStream(); 
       netstream.Write(img_byte, 0, img_byte.Length); 
       netstream.Close(); 
       client.Close(); 
      } 
      catch (Exception) 
      { 

      } 
     } 
     catch (Exception ee) 
     { 

     } 
    } 

    [StructLayout(LayoutKind.Sequential)] 
    struct CURSORINFO 
    { 
     public Int32 cbSize; 
     public Int32 flags; 
     public IntPtr hCursor; 
     public POINTAPI ptScreenPos; 
    } 

    [StructLayout(LayoutKind.Sequential)] 
    struct POINTAPI 
    { 
     public int x; 
     public int y; 
    } 

    [DllImport("user32.dll")] 
    static extern bool GetCursorInfo(out CURSORINFO pci); 

    [DllImport("user32.dll")] 
    static extern bool DrawIcon(IntPtr hDC, int X, int Y, IntPtr hIcon); 

    const Int32 CURSOR_SHOWING = 0x00000001; 

    public static Bitmap CaptureScreen(bool CaptureMouse) 
    { 
     Bitmap result = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height); 
     try 
     { 
      using (Graphics g = Graphics.FromImage(result)) 
      { 
       g.CopyFromScreen(0, 0, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy); 

       if (CaptureMouse) 
       { 
        CURSORINFO pci; 
        pci.cbSize = System.Runtime.InteropServices.Marshal.SizeOf(typeof(CURSORINFO)); 

        if (GetCursorInfo(out pci)) 
        { 
         if (pci.flags == CURSOR_SHOWING) 
         { 
          DrawIcon(g.GetHdc(), pci.ptScreenPos.x, pci.ptScreenPos.y, pci.hCursor); 
          g.ReleaseHdc(); 
         } 
        } 
       } 
      } 
     } 
     catch 
     { 
      result = null; 
     } 

     return result; 
    } 

    void WaitClientQuery()//receive data(client) 
    { 
     try 
     { 
      IPAddress ip ; 
      IPAddress.TryParse("192.168.1.64", out ip); 
      TcpListener listener = new TcpListener(ip, 4444); 
      listener.Start(); 
      while (true) 
      { 
       TcpClient client = listener.AcceptTcpClient(); 
       Thread thread = new Thread(new ParameterizedThreadStart(ReadMessage)); 
       thread.IsBackground = true; 
       thread.Start(client); 
      } 
     } 
     catch (Exception ex) 
     { 
     } 
    } 

    void ReadMessage(object obj) 
    { 
     try 
     { 
      TcpClient client = (TcpClient)obj; 
      NetworkStream netstream = client.GetStream(); 
      byte[] arr = new byte[client.ReceiveBufferSize ]; 
      int len = netstream.Read(arr, 0, client.ReceiveBufferSize); 
      if (len > 0) 
      { 
       try 
       { 

        Action act = delegate 
            { 
              MemoryStream strmImg = new MemoryStream(arr); 
              BitmapImage myBitmapImage = new BitmapImage(); 
              myBitmapImage.BeginInit(); 
              myBitmapImage.StreamSource = strmImg; 
              myBitmapImage.EndInit(); 
              img1.Source = myBitmapImage; 
            }; 
        this.Dispatcher.BeginInvoke(act); 

       } 
       catch (Exception ex) 
       { 
        string message = ex.Message; 
       } 

      } 
      netstream.Close(); 
      client.Close(); 
     } 
     catch (Exception ex) 
     { 
     } 
    } 

} 

附：因此，屏幕的程序編譯後： click to view

Answer 1

主根發送和接收特定數據類型我會建議 構建BinaryWriter使用默認值是8192字節導致client.ReceiveBufferSize，所以客戶端將無法接收已經從服務器傳輸足夠的圖像。在我的代碼中，我希望在客戶端看到正確的圖像大小，因此我使用BinaryWriter來傳輸圖像的長度。從客戶端我已經使用BinaryReader來精確讀取圖像的字節數和大小以節省帶寬。希望這有助於

在Send方法：

TcpClient client = new TcpClient("192.168.1.64", 4444); 
using (NetworkStream netstream = client.GetStream()) 
{ 
    using (BinaryWriter bw = new BinaryWriter(netstream)) 
    { 
     bw.Write(img_byte.Length); 
     bw.Write(img_byte, 0, img_byte.Length); 
    } 

    client.Close(); 
} 

在ReadMessage(object obj)

private void ReadMessage(object obj) 
    { 
     try 
     { 
      byte[] arr = null; 
      TcpClient client = (TcpClient) obj; 
      using (NetworkStream netstream = client.GetStream()) 
      { 
       using (BinaryReader br = new BinaryReader(netstream)) 
       { 
        var arrLen = new byte[4]; 
        br.Read(arrLen, 0, 4); 
        int len = BitConverter.ToInt32(arrLen, 0); 
        if (len > 0) 
        { 
         arr = new byte[len]; 

         int read = 0; 
         while (read != len) 
         { 
          read += br.Read(arr, read, arr.Length - read); 
         } 
        } 
       } 
      } 

      if (arr != null && arr.Length > 0) 
      { 
       try 
       { 

        Action act = delegate 
         { 
          MemoryStream strmImg = new MemoryStream(arr); 
          BitmapImage myBitmapImage = new BitmapImage(); 
          myBitmapImage.BeginInit(); 
          myBitmapImage.StreamSource = strmImg; 
          myBitmapImage.EndInit(); 
          img1.Source = myBitmapImage; 
         }; 
        this.Dispatcher.BeginInvoke(act); 

       } 
       catch (Exception ex) 
       { 
        string message = ex.Message; 
       } 

      } 

      client.Close(); 
     } 
     catch (Exception ex) 
     { 
     } 
    } 

Answer 2

我希望client.ReceiveBufferSize在客戶端上有錯誤信息 我會建議在循環讀取數據。

if(netstream.CanRead) 
{ 
       byte[] myReadBuffer = new byte[1024]; 
       int numberOfBytesRead = 0; 

       do 
     { 
        numberOfBytesRead = netstream.Read(myReadBuffer, 0, myReadBuffer.Length);        
       } 
       while(netstream.DataAvailable); 
} 

和數據保存到列表或MemoryStream的 或可能是更簡單的方法，你的服務器發送的所有數據之前，發送大小

netstream.Write(img_byte.Length); //does not work with NetworkStream 
netstream.Write(img_byte, 0, img_byte.Length); 

和客戶端可以先閱讀它來分配適當的緩衝。 要從NetworkStream

using (BinaryWriter writer = new BinaryWriter(netstream))