.h

#ifndef MYCLASS_H
#define MYCLASS_H
#include <QDialog>
#include <QLabel>
#include <QPushButton>

//此类继承QDialog
//类内创建需要用到的变量，函数等，在构造函数初始化中填充数据
class MessageBoxMy:public QDialog
{
    
    Q_OBJECT
public:
    //构造函数
    MessageBoxMy();
public:
    //按键对象创建
    QLabel *label1;
    QPushButton *questionButton;    //为正常的操作提示一个简单的询问
    QPushButton *informationButton; //为正常操作提示一个提示
    QPushButton *warningButton;     //提醒用户啊发生了一个错误
    QPushButton *criticalButton;    //警告用户发生了一个严重错误
    QPushButton *aboutButton;       //关于消息框
    QPushButton *aboutqtButton;     //关于QT消息框
    QPushButton *customButton;      //自定义消息框
private slots:
    void slotQuestion();
    void slotInformation();
    void slotWorning();
    void slotCritical();
    void slotAbout();
    void slotAboutQt();
    void slotCustom();

};


#endif // MYCLASS_H

.c

#include"myclass.h"
#include <QMessageBox>
#include <QGridLayout>
#include <QButtonGroup>
MessageBoxMy::MessageBoxMy()
{
    
    //设置主题
    setWindowTitle("MessageBox Use");

    label1 = new QLabel("About QT MessageBox");

    //创建按键并将文本显示在按键上
    questionButton = new QPushButton("Quessage");
    informationButton = new QPushButton("Information");
    warningButton = new QPushButton("warning");
    criticalButton = new QPushButton("critical");
    aboutButton = new QPushButton("about");
    aboutqtButton = new QPushButton("about qt");
    customButton = new QPushButton("custom");

    //布局管理
    QGridLayout *layout = new QGridLayout(this);
    layout->addWidget(label1,0,0,1,2);//放在第0行0列，跨度为1行2列（占一行两列）
    layout->addWidget(questionButton,1,0);
    layout->addWidget(informationButton,1,1);
    layout->addWidget(warningButton,2,0);
    layout->addWidget(criticalButton,2,1);
    layout->addWidget(aboutButton,3,0);
    layout->addWidget(aboutqtButton,3,1);
    layout->addWidget(customButton,4,0);

    //信号与槽连接
    connect(questionButton,SIGNAL(clicked()),this,SLOT(slotQuestion()));
    connect(informationButton,SIGNAL(clicked()),this,SLOT(slotInformation()));
    connect(warningButton,SIGNAL(clicked()),this,SLOT(slotWorning()));
    connect(criticalButton,SIGNAL(clicked()),this,SLOT(slotCritical()));
    connect(aboutButton,SIGNAL(clicked()),this,SLOT(slotAbout()));
    connect(aboutqtButton,SIGNAL(clicked()),this,SLOT(slotAboutQt()));
    connect(customButton,SIGNAL(clicked()),this,SLOT(slotCustom()));

}

//曹函数实现

//对于question消息框，调用时直接使用QMessageBox::question()即可
//第一个参数为消息框的父窗口指针
//第二个参数为消息框的标题栏
//第三个参数为消息框的问题提示
//第四个参数为对消息框按钮的设定QMessageBox提供了很多的标准按钮直接调用，用“|”连写，默认为OK
//第五个参数为消息框出现时，焦点默认在哪个按钮上
void MessageBoxMy::slotQuestion()
{
    
    switch(QMessageBox::question(this,"Question","已到达文档结尾，是否从头查找？",QMessageBox::Ok|QMessageBox::Cancel,QMessageBox::Ok))
    {
    
       case QMessageBox::Ok:
            label1->setText("Question Button/OK");
            break;
       case QMessageBox::Cancel:
            label1->setText("Question Button/Cancel");
            break;
        default:
            break;
    }
    return;
}

//QMessageBox::information()
//第一个参数为消息框的父窗口指针
//第二个参数为消息框的标题栏
//第三个参数为消息框的问题提示
//后面两个参数与Qusetion用法一样，但在使用中，经常省略，直接使用默认的OK
//Qusetion()和information()可以通用，使用Qusetion的地方都可以使用information替换
void MessageBoxMy::slotInformation()
{
    
    QMessageBox::information(this,"Information","填写任意想告诉于用户的信息!");
    return;
}


//MessageBoxMy::slotWorning()
//用法都大差不差
void MessageBoxMy::slotWorning()
{
    
    switch(QMessageBox::warning(this,"warning","是否保存对文档的修改",
                                QMessageBox::Save|QMessageBox::Discard|QMessageBox::Cancel,QMessageBox::Save))
    {
    
        case QMessageBox::Save:
            label1->setText("warning button/save");
            break;
        case QMessageBox::Discard:
            label1->setText("warning button/discard");
            break;
        case QMessageBox::Cancel:
            label1->setText("warning button/cancel");
            break;
        default:
            break;
    }
    return;
}

//Critical()消息框是在系统出现严重错误的时候对用户进行提醒
//通常只填前三个参数
void MessageBoxMy::slotCritical()
{
    
    QMessageBox::critical(this,"critical","致命错误");
    label1->setText("Critical Message!");
    return;
}

//提供系统的版本信息，只需提供信息而不需要用户反馈信息，只需填写前三个参数即可
void MessageBoxMy::slotAbout()
{
    
    QMessageBox::about(this,"About","测试试验");
    label1->setText("About test!");
    return;
}


//About qt消息框是QT预定好的消息框，用于提供QT的相关信息
//只需提供两个参数即可，显示内容是QT自己预定好的
void MessageBoxMy::slotAboutQt()
{
    
    QMessageBox::aboutQt(this,"AboutQT");
    label1->setText("AboutQT test!");
    return;
}
//
void MessageBoxMy::slotCustom()
{
    
    QMessageBox customMsgBox;//创建一个QMessageBox对象
    customMsgBox.setWindowTitle("Custom message box!!!");//设置标题栏
    //第一个参数为按钮显示的文字，第二个参数为按钮类型的描述
    QPushButton *lookbutton = customMsgBox.addButton("锁定",QMessageBox::ActionRole);//在窗口上添加按键并让按键显示固定文字
    QPushButton *unlookbutton = customMsgBox.addButton("解锁",QMessageBox::ActionRole);
    //取消按键只需要一个参数
    QPushButton *cancelbutton = customMsgBox.addButton(QMessageBox::Cancel);

    //customMsgBox.setIconPixmap(QPixmap(":/图片路径"));
    customMsgBox.setText("这是一个自定义的消息框");
    customMsgBox.exec();//进入消息循环，等待可能输入进行响应

    //判断按键按下显示对应字符
    if(customMsgBox.clickedButton() == lookbutton)
        label1->setText("LOOK");
    if(customMsgBox.clickedButton() == unlookbutton)
        label1->setText("UNlook");
    if(customMsgBox.clickedButton() == cancelbutton)
        label1->setText("cancel");
    return;
}

main.c

#include "mainwindow.h"
#include <QApplication>
#include "myclass.h"
int main(int argc, char *argv[])
{
    
    QApplication a(argc, argv);

    MessageBoxMy b;
    b.show();

    return a.exec();
}