QT中在MainWindow中代码添加控件

感谢 http://blog.csdn.net/noodle123/article/details/8260693
代码如下：

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QRadioButton *radio1 = new QRadioButton(tr("&Radio button 1"));
QVBoxLayout *vbox = new QVBoxLayout(this);
vbox->addWidget(radio1);
QWidget *centerWindow = new QWidget(this);
this->setCentralWidget(centerWindow);
centerWindow->setLayout(vbox);
}

Note: Creating a main window without a central widget is not supported. You must

have a central widget even if it is just a placeholder.

QWidget *centerWindow = new QWidget;

this->setCentralWidget(centerWindow);

QVBoxLayout *mainLayout = new QVBoxLayout;

mainLayout->addWidget(splitter);

centerWindow->setLayout(mainLayout);