Qt Code: 
  1. #include <QtGui> 
  2. #include <QImage>
  3. #include "kuvaclient.h"
  4.  
  5.  
  6. // including <QtGui> saves us to include every class user, <QString>, <QFileDialog>,...
  7.  
  8. KuvaClient::KuvaClient(QDialog *parent)
  9. {
  10. 	setupUi(this); // this sets up GUI
  11.  
  12. 	tcpSocket = new QTcpSocket(this);
  13. 	sockStream = new QDataStream(tcpSocket);
  14. 	file = new QFile("testi.bmp");
  15. 	if(file->exists())
  16. 		file->remove();
  17. 	file->open(QIODevice::ReadWrite);
  18.  
  19.     numberFrame=0;
  20.     fileStream = new QDataStream(file);
  21.     tcpSocket->abort();
  22.     tcpSocket->connectToHost("masa",1200);
  23. 	connect(vasen, SIGNAL( clicked() ), this, SLOT( Vasenpaina()));
  24. 	connect(oikea, SIGNAL( clicked() ), this, SLOT( Oikeapaina()));
  25.     connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(readImage()));
  26.  
  27.     connect(tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)),
  28.             this, SLOT(displayError(QAbstractSocket::SocketError)));
  29. }
  30.  
  31. void KuvaClient::Vasenpaina()
  32. {
  33.  
  34.     tcpSocket->abort();
  35.    tcpSocket->connectToHost("localhost",1200);
  36.    numberFrame=numberFrame+1;
  37.    QString number=number.setNum(numberFrame);
  38.    //koe->setText(number);
  39.  
  40.     tcpSocket->write(number);
  41.  
  42.  
  43.  
  44.  
  45. }
  46. void KuvaClient::readImage()
  47. {
  48.  
  49. 		//tcpSocket->seek(0);
  50. 	char *buffer = new char[65536];
  51. 	//int count = tcpSocket->bytesAvailable();
  52. 	//sockStream->resetStatus();
  53. 	while(!sockStream->atEnd())
  54. 	{
  55. 		int src = sockStream->readRawData(buffer, 65536);
  56. 		int rcv = fileStream->writeRawData(buffer, src);
  57. 		int xxx = 0;
  58. 		xxx++;
  59. 	}
  60.  
  61. 	delete[] buffer;
  62. 	file->flush();
  63.    	QImage someimage("testi.bmp");
  64.     QPixmap preview; 
  65.     preview = preview.fromImage(someimage);
  66.  
  67.     label->setPixmap(preview); 
  68. 	tcpSocket->waitForBytesWritten();
  69.  
  70.  
  71. }
  72. void KuvaClient::Oikeapaina()
  73. {
  74.  
  75.  
  76.    	tcpSocket->abort();
  77.     tcpSocket->connectToHost("locahost",1200);
  78.        numberFrame++;
  79.    	/*QString number=number.setNum(numberFrame);
  80.     tcpSocket->write(number.toLatin1() );
  81. 	tcpSocket->deleteLater();
  82. */
  83.  
  84. }
  85. void KuvaClient::displayError(QAbstractSocket::SocketError socketError)
  86. {
  87.     switch (socketError) {
  88.     case QAbstractSocket::RemoteHostClosedError:
  89.         break;
  90.     case QAbstractSocket::HostNotFoundError:
  91.         QMessageBox::information(this, tr("Fortune Client"),
  92.                                  tr("The host was not found. Please check the "
  93.                                     "host name and port settings."));
  94.         break;
  95.     case QAbstractSocket::ConnectionRefusedError:
  96.         QMessageBox::information(this, tr("Fortune Client"),
  97.                                  tr("The connection was refused by the peer. "
  98.                                     "Make sure the fortune server is running, "
  99.                                     "and check that the host name and port "
  100.                                     "settings are correct."));
  101.         break;
  102.     default:
  103.         QMessageBox::information(this, tr("Fortune Client"),
  104.                                  tr("The following error occurred: %1.")
  105.                                  .arg(tcpSocket->errorString()));
  106.     }
  107.  
  108.  
  109. }
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This is my client code.It' writes message to server,but i can't read message from socket in the server side.