Hello, I dont know why this simple server/client doesn't work.
A client send a string to the server and the server has just to show it into the GUI.
I created the ui_client.h and ui_server.h to implement the GUI

CLIENT CODE
client.h
Qt Code: 
  1. class client : public QMainWindow
  2. {
  3.     Q_OBJECT
  4.  
  5. public:
  6.     client();
  7.     ~client();
  8.  
  9. private slots:
  10. 	void connectToServer();
  11. 	void sendRequest();
  12. 	void updateTableWidget();
  13. 	void stopSearch();
  14. 	void connectionClosedByServer();
  15. 	void error();
  16.  
  17. private:
  18.     void closeConnection();
  19.     QTcpSocket tcpSocket;
  20.     quint16 nextBlockSize;
  21.     Ui::MainWindowClient ui;
  22. };
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client.cpp
Qt Code: 
  1. #include <QtNetwork>
  2. #include "client.h"
  3.  
  4. client::client()
  5. {
  6.     ui.setupUi(this);
  7.     connect(ui.pushButtonConnect, SIGNAL(clicked()),this, SLOT(connectToServer()));
  8.  
  9.     connect(&tcpSocket, SIGNAL(connected()), this, SLOT(sendRequest()));
  10.     connect(&tcpSocket, SIGNAL(disconnected()),this, SLOT(connectionClosedByServer()));
  11.     connect(&tcpSocket, SIGNAL(readyRead()),this, SLOT(updateTableWidget()));
  12.     connect(&tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)),this, SLOT(error()));
  13. }
  14.  
  15. client::~client()
  16. {
  17.  
  18. }
  19.  
  20.  
  21. void client::connectToServer()
  22. {
  23. 	tcpSocket.connectToHost(QHostAddress::LocalHost, 6178);
  24. 	ui.textBrowserStatus->setHtml("Connecting to server...");
  25. }
  26.  
  27. void client::sendRequest()
  28. {
  29.     QByteArray block;
  30.     QDataStream out(&block, QIODevice::WriteOnly);
  31.     out.setVersion(QDataStream::Qt_4_1);
  32.     out << quint16(0) << QString("it's me!");
  33.  
  34.     out.device()->seek(0);
  35.     out << quint16(block.size() - sizeof(quint16));
  36.     tcpSocket.write(block);
  37.  
  38.     ui.textBrowserStatus->setHtml(tr("Sending request..."));	
  39. }
  40.  
  41. void client::updateTableWidget(){}
  42.  
  43. void client::stopSearch(){}
  44.  
  45. void client::connectionClosedByServer()
  46. {
  47. 	 closeConnection();
  48. 	 ui.textBrowserStatus->setHtml("error connectionClosedByServer");
  49. }
  50.  
  51. void client::error()
  52. {
  53. 	 closeConnection();
  54. 	 ui.textBrowserStatus->setHtml(tcpSocket.errorString()); //-> I recive an "unknow error" on the GUI
  55. }
  56.  
  57. void client::closeConnection()
  58. {
  59. 	tcpSocket.close();
  60. }
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SERVER CODE
server.h
Qt Code: 
  1. #include <QtGui/QWidget>
  2. #include <QTcpServer>
  3. #include "ui_server.h"
  4.  
  5. class server : public QTcpServer, public QMainWindow
  6. {
  7.     Q_OBJECT
  8.  
  9. public:
  10.     server();
  11.     ~server();
  12. private:
  13. 	void incomingConnection(int socketId);
  14. private:
  15.     Ui::MainWindowServer ui;
  16. };
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server.cpp
Qt Code: 
  1. #include <QtGui>
  2. #include "server.h"
  3. #include "clientsocket.h"
  4.  
  5. server::server()
  6. {
  7. 	ui.setupUi(this);
  8. 	ui.textBrowserOut->setHtml("ready....");
  9. }
  10.  
  11. server::~server()
  12. {
  13.  
  14. }
  15.  
  16. void server::incomingConnection(int socketId)
  17. {
  18. 	ui.textBrowserOut->setHtml(QString::number(socketId, 10));  //->I can't see the socketid in the GUI
  19. 	ClientSocket *socket = new ClientSocket(ui.textBrowserOut);
  20. 	socket->setSocketDescriptor(socketId);	
  21. }
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clientsocket.h
Qt Code: 
  1. #include <QTcpSocket>
  2. #include <QtGui>
  3.  
  4. class ClientSocket : public QTcpSocket
  5. {
  6.     Q_OBJECT
  7.  
  8. public:
  9.     ClientSocket(QTextBrowser *textBrowser);
  10.  
  11. private slots:
  12.     void readClient();
  13.  
  14. private:
  15.     QTextBrowser *textBrowserPark;
  16.     quint16 nextBlockSize;
  17. };
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clientsocket.cpp
Qt Code: 
  1. #include <QtNetwork>
  2. #include <cstdlib>
  3. #include <QtGui>
  4.  
  5. #include "clientsocket.h"
  6.  
  7. ClientSocket::ClientSocket(QTextBrowser *textBrowser)
  8. {
  9. 	this->textBrowserPark = textBrowser;
  10.     connect(this, SIGNAL(readyRead()), this, SLOT(readClient()));
  11.     connect(this, SIGNAL(disconnected()), this, SLOT(deleteLater()));
  12.  
  13.     nextBlockSize = 0;	
  14. }
  15.  
  16. void ClientSocket::readClient()
  17. {
  18. 	this->textBrowserPark->setHtml("....waiting");
  19. 	QDataStream in(this);
  20.     in.setVersion(QDataStream::Qt_4_1);
  21.  
  22.     if (nextBlockSize == 0) {
  23.         if (bytesAvailable() < sizeof(quint16))
  24.             return;
  25.         in >> nextBlockSize;
  26.     }
  27.  
  28.     if (bytesAvailable() < nextBlockSize)
  29.         return;
  30.  
  31.  
  32.     QString msg;
  33.  
  34.     in >> msg;
  35.     this->textBrowserPark->setHtml(msg);
  36.     //i should reply to the client....
  37.     close();
  38. }
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main.cpp
Qt Code: 
  1. #include "server.h"
  2.  
  3. #include <QtGui>
  4. #include <QApplication>
  5.  
  6. int main(int argc, char *argv[])
  7. {
  8.     QApplication a(argc, argv);
  9.     server s;
  10.     if (!s.listen(QHostAddress::Any, 6178)) {
  11.         return 1;
  12.     }
  13.  
  14.     server w;
  15.     w.show();
  16.     a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
  17.     return a.exec();
  18. }
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Any ideas?