最近在学习Qt框架，今天学习了一下消息框的使用， 现整理出来以作记录。

在程序运行时，经常需要提示用户一些信息，比如警告啊，提示啊，建议啊之类的东西。这些东西基本上是通过消息框与用户进行交互的，Qt中主要是用QMessageBox类来加以实现的。

消息框一般分为七种：

Question询问消息框：为正常的操作提供一个简单的询问

Information信息消息框：为正常操作提供一个提示

Warning提示消息框：提醒用户发生了一个错误

Critical警告消息框：警告用户发生了一个严重错误

About关于消息框：自定义的关于信息

AboutQt关于Qt消息框：Qt自身的关于信息

Custom自定义消息框：自己定制消息框

具体用法见源码以及分析：

Dialog.pro

#-------------------------------------------------## Project created by QtCreator 2015-10-24T17:32:35##-------------------------------------------------QT += core guigreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsTARGET = DialogTEMPLATE = appSOURCES += main.cpp dialog.cppHEADERS += dialog.h

dialog.h

#ifndefDIALOG_H#defineDIALOG_H#include<QDialog>#include<QGridLayout>#include<QPushButton>#include<QLabel>#include<QMessageBox>class Dialog: public QDialog{ Q_OBJECTpublic: Dialog(QWidget *parent = 0); ~Dialog();public://配置部件和布局 QLabel *label; QPushButton *QuestionBtn,*InformationBtn,*WarningBtn,*CriticalBtn,*AboutBtn,*AboutQtBtn,*CustomBtn; QGridLayout *layout,*layoutLabel,*layoutBtn;protected slots://各种按钮的槽 void slotQuestion(); void slotInformation(); void slotWarning(); void slotCritical(); void slotAbout(); void slotAboutQt(); void slotCustom();};#endif// DIALOG_H

dialog.cpp

#include"dialog.h"Dialog::Dialog(QWidget *parent) : QDialog(parent){ setWindowTitle("QMessageBox"); QuestionBtn=new QPushButton("Question"); InformationBtn=new QPushButton("Information"); WarningBtn=new QPushButton("Warning"); CriticalBtn=new QPushButton("Critical"); AboutBtn=new QPushButton("About"); AboutQtBtn=new QPushButton("AboutQt"); CustomBtn=new QPushButton("Custom"); label=new QLabel("About Qt MessageBox:"); layout=new QGridLayout(this); layoutLabel=new QGridLayout; layoutBtn=new QGridLayout; layoutLabel->addWidget(label,0,0); layoutBtn->addWidget(QuestionBtn,1,0); layoutBtn->addWidget(InformationBtn,1,1); layoutBtn->addWidget(WarningBtn,2,0); layoutBtn->addWidget(CriticalBtn,2,1); layoutBtn->addWidget(AboutBtn,3,0); layoutBtn->addWidget(AboutQtBtn,3,1); layoutBtn->addWidget(CustomBtn,4,0); layoutBtn->setSpacing(15); //嵌套布局 layout->addLayout(layoutLabel,0,0); layout->addLayout(layoutBtn,1,0); setFixedSize(300,220);//固定大小 connect(QuestionBtn,SIGNAL(clicked()),this,SLOT(slotQuestion())); connect(InformationBtn,SIGNAL(clicked()),this,SLOT(slotInformation())); connect(WarningBtn,SIGNAL(clicked()),this,SLOT(slotWarning())); connect(CriticalBtn,SIGNAL(clicked()),this,SLOT(slotCritical())); connect(AboutBtn,SIGNAL(clicked()),this,SLOT(slotAbout())); connect(AboutQtBtn,SIGNAL(clicked()),this,SLOT(slotAboutQt())); connect(CustomBtn,SIGNAL(clicked()),this,SLOT(slotCustom()));}Dialog::~Dialog(){}//直接调用AboutQt，设置句柄和标题即可void Dialog::slotAboutQt(){ QMessageBox::aboutQt(this,"This is the title");}//以下三个函数均是设置句柄标题和信息即可，也可以在最后设置默认按钮，一般默认的是QMessageBox::Ok。void Dialog::slotAbout(){ QMessageBox::about(this,"About","This is the label.");}void Dialog::slotCritical(){ QMessageBox::critical(this,"Critical","This is the label.");}void Dialog::slotInformation(){ QMessageBox::information(this,"Information","This is the label.");}//自定义消息框void Dialog::slotCustom(){ QMessageBox customMsgBox; customMsgBox.setWindowTitle("Custom message box"); //添加按键 QPushButton *lockBtn=customMsgBox.addButton("Lock",QMessageBox::ActionRole); QPushButton *unlockBtn=customMsgBox.addButton("Unlock",QMessageBox::ActionRole); QPushButton *cancelBtn=customMsgBox.addButton(QMessageBox::Cancel);//注意cancel不能指定Text //customMsgBox.setIconPixmap(QPixmap("a.png"));//设置图片 customMsgBox.setText("This is the label"); customMsgBox.exec();//执行消息框 QPushButton *msg=(QPushButton*)customMsgBox.clickedButton();//接受按键信息 //判断按键 if(msg==lockBtn) label->setText("Custom button /lock"); if(msg==unlockBtn) label->setText("Custom button /unlock"); if(msg==cancelBtn) label->setText("Custom button /cancel");}void Dialog::slotQuestion(){ //QMessageBox::**question()**函数，传入句柄，标题，文本，按钮值，返回按键对应的值，最后也可以加默认按键的位置 int msg=QMessageBox::question(this,"Question","This is the label.",QMessageBox::Ok|QMessageBox::Cancel); //判断选择信息 switch(msg){ case QMessageBox::Ok: label->setText("Question button /OK"); break; case QMessageBox::Cancel: label->setText("Question button /Cancel"); break; default: break; }}void Dialog::slotWarning(){ //QmessageBox::warning()函数同Question函数 int msg=QMessageBox::warning(this,"Question","This is the label.",QMessageBox::Save|QMessageBox::Discard|QMessageBox::Cancel,QMessageBox::Save); switch(msg){//判断选择信息 case QMessageBox::Save: label->setText("Warning button /Save"); break; case QMessageBox::Cancel: label->setText("Warning button /Cancel"); break; case QMessageBox::Discard: label->setText("Warning button /Discard"); break; default: break; }}

##main.cpp

#include"dialog.h"#include<QApplication>int main(intargc,char*argv[]){ QApplicationa(argc, argv); Dialog w; w.show(); return a.exec();}

运行截图

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。