hi friends,
please help
i create a code to embed gtk window to my Qt app ..
mainwindow.cpp
Qt Code: 
  1. procc2 = new QProcess();
  2.       procc2->setProcessChannelMode(QProcess::MergedChannels);
  3.       connect(procc2, SIGNAL(readyReadStandardOutput()), this, SLOT(readFromStdout2()));
To copy to clipboard, switch view to plain text mode 

this is a timer function calling every 400 milli sec
Qt Code: 
  1. MainWindow::timeout{
  2.      if(...)
  3.     {
  4.      QString program4 = "./gtk_demo2";
  5.      QStringList arguments2;
  6.                 if(procc2->state() != QProcess::Running)
  7.                 {
  8.                         procc2->start(program4, arguments2);
  9.                 }
  10.         }
To copy to clipboard, switch view to plain text mode 

readfromstdout() function will call the function to embed the process
Qt Code: 
  1. MainWindow::readFromStdout2()
  2. {
  3.         int j = 0;
  4.         bool ok;
  5.         QString out;
  6.         printf("in singal fin\n");
  7.         out = procc2->readAllStandardOutput();
  8.         j = out.toInt(&ok, 16);
  9.         printf("j =%d\n",j);
  10.         if(j == 1)
  11.                 printf("device not connected\n");
  12.         else{
  13.                 printf("the device connected\n");
  14.                embed();
  15.            }
  16.  
  17.   }
To copy to clipboard, switch view to plain text mode 

this is my code and the function embed() will embed the "gtk_demo" window if it returns 0 or anything ...
the problem is on first time if i spawn the signal "readyReadStandardOutput()"
is not emitted and readFromStdout2() slot is not called .
i closed the spawned gtk application "gtk_demo" and as i put the procc in loop again it spawn "gtk_demo" its emitting "readyReadStandardOutput()" and embedding perfectly ... why??
i changed gtk application to a Qt application and try the same thing its worked in the first attempt ...

please help me ...