QgridLayout例子QGridLayout使用方法，qlayout添加button实例

#include "mainwindow.h"#include <QApplication>#include <QtGui>#include "qwidget.h"#include "qgridlayout.h"#include "qpushbutton.h"//qt layout例子，qt layout用法，qt qgridlayout demo//编译环境：qt5.5，mingGW，windows 7 旗舰版，x64//建一个没有ui的qt工程，最简单的qt工程，把下面代码拷贝到main.c里面编译及可通过int main(int argc, char *argv[]){    QApplication app(argc, argv);    QMainWindow *window = new QMainWindow();    window->setWindowTitle(QString::fromUtf8("QGridLayout Col and Row Span"));    window->resize(330, 220);    QWidget *centralWidget = new QWidget(window);    QGridLayout *layout = new QGridLayout();    centralWidget->setLayout(layout);//qt添加控件方法，qt窗口添加按钮，qt添加按钮，qt添加layout    //ROW 1    //Add Items to QGridLayout Here    //Row and Column counts are set Automatically    layout->addWidget(new QPushButton("Button  1"),0,0);    layout->addWidget(new QPushButton("Button  2"),0,1);    layout->addWidget(new QPushButton("Button  3"),0,2);    layout->addWidget(new QPushButton("Button  4"),0,3);//qt控件添加，Qt gridlayout合并，widget添加按钮，widget添加按键    //ROW 2    layout->addWidget(new QPushButton("Button  5"),1,0);    //set Row and Col Span of "Button 6" to 2    //Set SizePolicy of "Button 6" to Expanding for Both Directions    //So that Row and Col Span can be seen clearly    QPushButton* button6 = new QPushButton("Button  6");//中间的按钮6 button 6占领了框中间两行两列。变成一个大按钮    button6->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);    layout->addWidget(button6,1,1,2,2);//前面量个1，表示第一行，和第一列，    //qt的tab，layout计数都是0开始。第一行，合并的函数是2行，第一列，合并的列数是2列    layout->addWidget(new QPushButton("Button  7"),1,3);    //ROW 3    layout->addWidget(new QPushButton("Button  8"),2,0);    layout->addWidget(new QPushButton("Button  9"),2,3);    //ROW 4    layout->addWidget(new QPushButton("Button 10"),3,0);    layout->addWidget(new QPushButton("Button 11"),3,1);    layout->addWidget(new QPushButton("Button 12"),3,2);    layout->addWidget(new QPushButton("Button 13"),3,3);    window->setCentralWidget(centralWidget);    window->show();    return app.exec();}