QTDesigner的QVBoxLayout自動隨窗口拉伸

在MainWindow的構造函數中添加如下代碼：
//設置Ui
ui.setupUi(this);

//使Ui可自適應父窗口大小
QVBoxLayout* mainLayout = new QVBoxLayout;
mainLayout->addWidget(ui.verticalLayoutWidget);
setLayout(mainLayout);

或

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QVBoxLayout* mainLayout = new QVBoxLayout;
mainLayout->addWidget(ui->verticalLayoutWidget);
ui->centralWidget->setLayout(mainLayout);
}

http://www.kxtry.com/archives/868