Udp圖像流，delphi indy10

Question

我正在使用帶有indy10組件的delphi xe4，我想將一個圖像從Tidudpclient發送到Tidudpserver。 我已經使用tcp組件完成了此操作，但相同的代碼不能與udp一起使用。 我怎么能這樣做？ 提前致謝！

TImage中（客戶端）---> streamUDP - >的TImage（服務器）

客戶端-----------------------------------------------發送圖片

var
    pic: tbitmap;
       Strm : TMemoryStream;
        img2:Timage;

    buffer:TIdBytes;
    begin

        try
          img2:=Timage.Create(nil);
          pic:=Tbitmap.Create;
          Takekpic(pic);     
          BMPtoJPG(pic,img2);
          Strm := TMemoryStream.Create;
          img2.Picture.bitmap.SaveToStream(strm);
          Strm.Position:=0;
          ReadTIdBytesFromStream(Strm,buffer,SizeOf(Strm),0);
          IdTrivialFTPServer1.SendBuffer('192.168.17.128',1234,buffer);
        finally
             strm.Free;
          end; 
    end;

服務器端 - - - - - - - - - - - - - - - - - - - - - - - - ----閱讀圖片

procedure TForm6.IdTrivialFTP1UDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
    var
Strm : TMemoryStream;
Jpg: TJpegImage;

begin
      Strm := TMemoryStream.Create;
      try    

         WriteTIdBytesToStream(Strm,AData,SizeOf(AData),0);
         strm.Position:=0;
         Jpg := TJpegImage.Create;
         jpg.LoadFromStream(Strm);  <---- error while reading (JPEG Error #53)
         img1.Picture.assign(jpg);
      finally
         strm.Free;
         Jpg.Free;
      end;
end;

這段代碼有什么不對嗎？

Answer 1

TIdUDPClient和TIdUDPServer不支持發送/接收TStream數據。 您可以將圖像數據保存到TStream ，但必須使用TIdBytes塊發送/接收它。

或者，使用TIdTrivialFTP和TIdTrivialFTPServer來實現TFTP，這是一種基於UDP的文件傳輸協議。 它們使用TStream對象進行操作

更新 ：例如：

客戶：

var
  bmp: TBitmap;
  jpg: TJPEGImage;
  Strm : TMemoryStream;
begin
  Strm := TMemoryStream.Create;
  try
    jpg := TJPEGImage.Create;
    try
      bmp := TBitmap.Create;
      try 
        Takekpic(bmp);     
        jpg.Assign(bmp);
      finally
        bmp.Free;
      end;
      jpg.SaveToStream(Strm);
    finally
      jpg.Free;
    end;
    Strm.Position := 0;
    {
    These can be assigned ahead of time...
    IdTrivialFTP1.Host := '192.168.17.128';
    IdTrivialFTP1.Port := 1234;
    }
    IdTrivialFTP1.Put(Strm, 'image.jpg');
  finally
    Strm.Free;
  end; 
end;

服務器：

procedure TForm6.IdTrivialFTPServer1WriteFile(Sender: TObject; var FileName: String; const PeerInfo: TPeerInfo; var GrantAccess: Boolean; var AStream: TStream; var FreeStreamOnComplete: Boolean) of object;
begin
  if FileName = 'image.jpg' then
  begin
    GrantAccess := True;
    AStream := TMemoryStream.Create;
    FreeStreamOnComplete := True;
  end else
    GrantAccess := False;
end;

{
If you set TIdTrivialFTPServer.ThreadedEvent to False, this event handler
runs in the context of the main thread, so the UI can be accessed safely.
If you set IdTrivialFTPServer.ThreadedEvent to True, this event handler
runs in the context of a worker thread, so you will have to manually
synchronize with the main thread when updating the UI...
}
procedure TForm6.IdTrivialFTPServer1TransferComplete(Sender: TObject; const Success: Boolean; const PeerInfo: TPeerInfo; var AStream: TStream; const WriteOperation: Boolean);
var
  jpg: TJPEGImage;
begin
  if WriteOperation and Success then
  begin
    jpg := TJPEGImage.Create;
    try
      AStream.Position := 0;
      jpg.LoadFromStream(AStream);
      img1.Picture.Assign(jpg);
    finally
      jpg.Free;
    end;
  end;
end;