Qt 5 常用类及基本函数

//主要使用类
#include <Qstring>
#include <QMenu>
#include <QMenuBar>
#include <QToolBar>
#include <QTextEdit>
#include <QDockWidget>
#include <QStatusBar>
#include <QLabel>
#include <QDialog>
#include <QMessageBox>
#include <QFileDialog>

QMenuBar类; 在windows平台下提供MenuBar()函数配合setMenuBar()使用;在mac中要建立共享菜单则要用new QMenuBar生成菜单栏;

QDialog类;其对象有模态与非模态窗口;可用exec()(使程序停留在此),或show()区分;在动作触发时创建的对象,可用setAttribute(设置对象属性)来设置消毁时机;

QMessageBox类,QFileDialog类,对静态成员的使用;

QMessageBox类中对按键的选择判断可用switch; 

//菜单栏
    this->setMinimumSize(400, 200);
    QMenuBar *myBar = menuBar();
    this->setMenuBar(myBar);
    QMenu *File = new QMenu(QString("文件"));
    myBar->addMenu(File);

    File->addAction(QString("新建"),[=]{

    });
    File->addSeparator();
    File->addAction(QString("打开"), [=]{
        QFileDialog::getOpenFileName(this, QString("打开文件"), QString("./"), QString("Images (*.png *.xpm *.jpg)"));
    });
    QAction *Abt = myBar->addAction(QString("模态"));
    QAction *Abt1 = myBar->addAction(QString("非模态"));

    //工具栏
    QToolBar *ToBar = new QToolBar;
    this->addToolBar(ToBar);
    ToBar->addAction(QString("新建"),[=]{

    });
    ToBar->addAction(QString("打开"), [=]{

    });
    //工作区
    QTextEdit *txt1 = new QTextEdit;
    this->setCentralWidget(txt1);
    //悬浮窗
    QDockWidget *dock = new QDockWidget(QString("txt"));
    QTextEdit *txt2 = new QTextEdit;
    dock->setWidget(txt2);
    this->addDockWidget(Qt::RightDockWidgetArea, dock);
    //状态栏
    QStatusBar *StBar = new QStatusBar;
    this->setStatusBar(StBar);
    QLabel *Lab1 = new QLabel(QString("状态栏:"));
    QLabel *Lab2 = new QLabel(QString("12536"));
    StBar->addWidget(Lab1);
    StBar->addPermanentWidget(Lab2);

    //模态对话框
    connect(Abt, &QAction::triggered, [=]
    {
        QDialog *d1 = new QDialog;
        d1->show();
        d1->setAttribute(Qt::WA_DeleteOnClose);
    });
    //非模态
    connect(Abt1, &QAction::triggered, [=]
    {
        QDialog *d2 = new QDialog;
        d2->exec();
        d2->setAttribute(Qt::WA_DeleteOnClose);
    });

    //MessageBox
    QAction *about1 = myBar->addAction(QString("关于"));
    connect(about1, &QAction::triggered, [=]
    {
       QMessageBox::about(this, QString("关于"), QString("关于qt"));
    });

    QAction *about2 = myBar->addAction(QString("保存/关闭"));
    connect(about2, &QAction::triggered, [=]
    {
       QMessageBox::StandardButton i = QMessageBox::question(this, QString("关于2"), QString("多按键"),QMessageBox::Save | QMessageBox::Close);
        switch(i)
        {
        case QMessageBox::Save:
        {
            Lab2->setText(QString("保存成功"));
        }
            break;
        case QMessageBox::Close:
        {
            Lab2->setText(QString("关闭"));
        }
            break;
        default:
            break;
        }
    });