深入理解Qt中各种消息框对话框的使用

#-------------------------------------------------## 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

#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

#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;  }}

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