#include <qdialog.h>
#include <qapplication.h>
int main(int argc, char* argv[])
{
QApplication app( argc, argv );
QDialog* pDlgMain = new QDialog();
QDialog* pDlgMainSon = new QDialog(pDlgMain); //<--指定parent
pDlgMain->show();
delete pDlgMain;
pDlgMain = NULL;
pDlgMainSon->show();//完了,崩了
return 0;
}