多屏显示

QDesktopWidget* desktopWidget = QApplication::desktop();   //获取可用桌面大小  QRect deskRect = desktopWidget->availableGeometry();  //获取设备屏幕大小  QRect screenRect = desktopWidget->screenGeometry();  int sceenSizeX = screenRect.width();  int  sceenSizeY = screenRect.height();  //获取系统设置的屏幕个数（屏幕拷贝方式该值为1）  int  i= desktopWidget->screenCount();