void QWidget::setWindowState ( Qt::WindowStateswindowState )
此函数可以设置窗体的初始状态，Qt::WindowStates 一共有下面几种状态：
| Constant | Value | Description |
|---|---|---|
| Qt::WindowNoState | 0x00000000 | The window has no state set (in normal state). |
| Qt::WindowMinimized | 0x00000001 | The window is minimized (i.e. iconified). |
| Qt::WindowMaximized | 0x00000002 | The window is maximized with a frame around it. |
| Qt::WindowFullScreen | 0x00000004 | The window fills the entire screen without any frame around it. |
| Qt::WindowActive | 0x00000008 | The window is the active window, i.e. it has keyboard focus. |
使窗口最大化如下即可：
int main(int argc, char *argv[]) { QApplication a(argc, argv); MainWindow w; w.setWindowState(Qt::WindowMaximized); w.show(); return a.exec(); }