Qt学习笔记（Dialog）

#-------------------------------------------------
#
# Project created by QtCreator 2019-08-16T16:45:44
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = 03_QDialog
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

SOURCES += \
        main.cpp \
        mainwindow.cpp

HEADERS += \
        mainwindow.h

FORMS += \
        mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <QDialog>
#include <QMessageBox>
#include <QColorDialog>
#include <QFileDialog>
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    //actionnew 属于QAction 类，它的
    //点击新建菜单项，弹出对话框
    //非模态，打开对话框后还可以对其他窗口做操作
    //模态对话框，只能对相关一系列进程显示在最上层，不可以对其他窗口操作


    connect(ui->actionnew,&QAction::triggered,this,[=](){
        //对话框有两种
        //模态对话框 非模态对话框
//        QDialog dlg(this);
//        dlg.exec();//阻塞，进入消息循环
//        dlg.resize(200,200);
//非模态对话框
        //QDialog dlg2(this);//创建到了栈上，一闪而过
//        QDialog *dlg2=new QDialog(this);
//        dlg2->resize(100,100);
//        dlg2->show();
//        //防止资源泄露，所以要设置属性，防止有人一直点下去。。。。
//        //记住value 是 55的参数 Qt：：WA_DeleteOnClose//关闭窗口释放指针
//        dlg2->setAttribute(Qt::WA_DeleteOnClose);




        //使用标准的对话框
        //静态方法可以直接用类名调用
        //错误对话框
        QMessageBox::critical(this,"错误","critical");

        //信息对话框
        QMessageBox::information(this,"信息","info");

        //比较关键,询问对话框
        //五个参数：1，父亲 2，标题，3，提示内容， 4，按键类型，5，关联回车按键
        //根据返回值来确定具体点了哪个按钮
      if(QMessageBox::Save == QMessageBox::question(this,"问题","question",QMessageBox::Save|QMessageBox::Cancel,QMessageBox::Cancel))  //寻找默认的按钮文字
      {
          qDebug()<<"点击的保存";
      }
      else
      {
         qDebug()<<"点击的取消";
      }
        //警告对话框
      QMessageBox::warning(this,"警告","warning！");


      //颜色对话框
      QColor color=QColorDialog::getColor(QColor(0,255,0));
      qDebug()<<color.red()<<color.green()<<color.blue();
      //所有属性都可以拿到手。

      //文件对话框  参数1 父亲 2,提示 3，默认路径 ，4 可以过滤文件,但不会过滤文件夹
      //会返回选取文件的路径
      QString path=QFileDialog::getOpenFileName(this,"打开文件","C:\\Users\\dawnl\\Desktop\\","(*.txt *.png)");
     qDebug()<<path;





        qDebug()<<"弹出对话框";
    });
}

MainWindow::~MainWindow()
{
    delete ui;
}

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget"/>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>400</width>
     <height>23</height>
    </rect>
   </property>
   <widget class="QMenu" name="menu">
    <property name="title">
     <string>文件</string>
    </property>
    <addaction name="actionnew"/>
    <addaction name="actionopen"/>
   </widget>
   <addaction name="menu"/>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
   <addaction name="actionnew"/>
   <addaction name="actionopen"/>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
  <action name="actionnew">
   <property name="text">
    <string>new</string>
   </property>
  </action>
  <action name="actionopen">
   <property name="text">
    <string>open</string>
   </property>
  </action>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>