qt学习（六）窗口

1.Dialog

#ifndef MYDIALOG_H
#define MYDIALOG_H

#include <QDialog>

class MyDialog : public QDialog
{
    Q_OBJECT
public:
    explicit MyDialog(QWidget *parent = 0);

    QString _strDir;
    void paintEvent(QPaintEvent *);

signals:

public slots:
    void slotButtonClick();

};

#endif // MYDIALOG_H

#include "mydialog.h"

#include "MyDialog.h"
#include <QPushButton>
#include <QDebug>
#include <QFileDialog>
#include <QFileInfo>

#include <QColorDialog>
#include <QFontDialog>
#include <QMessageBox>
#include <QPainter>
MyDialog::MyDialog(QWidget *parent) :
    QDialog(parent)
{
    QPushButton* button = new QPushButton("Click me", this);
    connect(button, SIGNAL(clicked()), this, SLOT(slotButtonClick()));
}
void MyDialog::slotButtonClick()
{
    #if 0
    QDialog *dlg=new QDialog;
    int ret;
    ret=dlg->exec();//在模块对话框中，exec有自己的消息循环，并且把app的消息循环接管
    QPushButton *button=new QPushButton(dlg);
    connect(button,SIGNAL(clicked()),dlg,SLOT(accept()));
    //如果Dialog是通过exec来显示，那么可以通过accept或者reject来关闭窗口
    //如果Dialog是通过show来显示，那么可以通过close来关闭窗口，这个和QWidget一样的

    //有许多特殊的dialog：打印预览，打印，MessageBox，颜色选择，字体选择
    if(ret==QDialog::Accepted)
    {
        qDebug()<<"Accepted";
    }
    if(ret==QDialog::Rejected)
    {
        qDebug()<<"rejected";
    }
  #endif
  #if 0
    //第一次的时候选择目录，下次进来的时候是第一次保存的目录
    //打开文件，保存文件
    QString strFilename=QFileDialog::getSaveFileName(NULL,
                                                     "Select file for save",
                                                     _strDir,"pic file (*.png *.jpg)");
   #endif
   #if 0
    //选择文件
    QString strFilename=QFileDialog::getOpenFileName(NULL,
                                                     "Select file for save",
                                                     _strDir,"pic file (*.png *.jpg)");
    #endif
    //选择目录
    #if 0
    QString strFilename=QFileDialog::getExistingDirectory();
    if(strFilename.isEmpty())
    {
        qDebug()<<"select note";
        return ;

    }

    qDebug()<<strFilename;
    QFileInfo fileInfo(strFilename);
    _strDir=fileInfo.filePath();
    #endif
    #if 0
    //颜色对话框
    QColorDialog color;
    color.exec();
    QColor c=color.selectedColor();//选择的颜色
    #endif
    #if 0
    //字体对话框
    QFontDialog fontDialog;
    fontDialog.exec();
    QFont font=fontDialog.selectedFont();
    #endif

    //提示对话框
//     QMessageBox::information(this,"Error","Eror msgs...");
//     QMessageBox::warning(this,"Error","Eror msgs...");
//     QMessageBox::critical(this,"Error","Eror msgs...");
     int ret=QMessageBox::question(this,"???","realy do...",QMessageBox::Yes|QMessageBox::No
                                   |QMessageBox::YesAll|QMessageBox::NoAll);//增加按钮
     if(ret==QMessageBox::Yes)
     {
         qDebug()<<"user select yes";
     }
     if(ret==QMessageBox::No)
     {
         qDebug()<<"user select no";
     }



}
void MyDialog::paintEvent(QPaintEvent *)
{
    QPainter p(this);
    p.drawLine(QLine(0,0,200,200));
}
#include <QApplication>

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);

    MyDialog dlg;
    dlg.show();

    return app.exec();
}

2.mainWindow

#ifndef MYMAINWINDOW_H
#define MYMAINWINDOW_H

#include <QMainWindow>
#include <QWidget>
#include<QLabel>
#include<QPainter>
#include<QMouseEvent>
#include"myview.h"
#include<QMenu>
#include<QSystemTrayIcon>//托盘
class MyMainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MyMainWindow(QWidget *parent = nullptr);
    QLabel *_label;
    MyView *_view;//中心区域封装在view中，画图等操作在view上进行操作；
    QMenu *_menu;
    QSystemTrayIcon *_icon;
    void paintEvent(QPaintEvent *);
    void mousePressEvent(QMouseEvent *);//右键弹出菜单
    bool event(QEvent *event);
    bool eventFilter(QObject *watched, QEvent *event);

signals:

public slots:
    void slotOpen();
    void slotActioned(QSystemTrayIcon::ActivationReason);
};

#endif // MYMAINWINDOW_H

#ifndef MYVIEW_H
#define MYVIEW_H

#include <QWidget>
#include<QPainter>
class MyView : public QWidget
{
    Q_OBJECT
public:
    explicit MyView(QWidget *parent = nullptr);
    void paintEvent(QPaintEvent *);

signals:

public slots:
};

#endif // MYVIEW_H

#include "mymainwindow.h"
#include<QApplication>
#include<QMenu>
#include<QMenuBar>//菜单栏
#include<QAction>//菜单上的单项，可以触发
#include<QToolBar>
#include<QStatusBar>
#include<QFileDialog>
#include<QtDebug>
#include<QPainter>
#include<QCursor>//鼠标当前的位置
MyMainWindow::MyMainWindow(QWidget *parent) : QMainWindow(parent)
{
   /*编程建议：最好先把所有的Action创建好，menu和toolbar从中选择*/
   /*加菜单*/
    QMenuBar *pMenuBar=menuBar();
    QMenu *menu=pMenuBar->addMenu("&File");
    QAction *openAction=menu->addAction("&open",this,SLOT(slotOpen()),QKeySequence::Open);//快捷键open是ctrl+o,根据平台决定
    QAction *saveAction=menu->addAction("&save",this,SLOT(slotOpen()),QKeySequence::Save);
    _menu=menu;
    //加了一条线区分
    menu->addSeparator();
    QAction *closeAction=menu->addAction("&exit",this,SLOT(slotOpen()),QKeySequence::Close);//菜单前面也可以加图标
    closeAction->setToolTip("close window");

    /*toolbar 工具栏*/
    QToolBar* toolBar=this->addToolBar("MyToolBar");
    toolBar->addAction(openAction);
    toolBar->addAction(saveAction);
    toolBar->addAction(closeAction);

    /*status bar 状态栏*/
    QStatusBar *pStatusBar=this->statusBar();
    pStatusBar->addWidget(_label=new QLabel("OK"));

    _label->setText("<font color=red>Processing ...</font>");

    /*别的控件占用之后，剩下的区域都是CentralWidget*/
    _view=new MyView();
    this->setCentralWidget(_view);
    //创建托盘
    _icon=new QSystemTrayIcon;
    _icon->setIcon(QIcon("../bing.ico"));
    _icon->setToolTip("This is tray icon test");
    _icon->show();
    _icon->setContextMenu(_menu);//点一下托盘会有菜单
    connect(_icon,SIGNAL(activated(QSystemTrayIcon::ActivationReason)),
            this,SLOT(slotActioned(QSystemTrayIcon::ActivationReason));
            
    this->installEventFilter(this);

}

void MyMainWindow::paintEvent(QPaintEvent *)
{
    QPainter p(this);
    p.drawPixmap(QPoint(0,0),QPixmap("../map.png"));//单纯的这样画，会遮挡菜单栏
}

void MyMainWindow::mousePressEvent(QMouseEvent *ev)
{
    if(ev->button()==Qt::RightButton)
        _menu->exec(QCursor::pos());//QCursor::pos返回的位置的窗口坐标系鼠标的位置，而ev->pos()是桌面坐标系的位置
}

bool MyMainWindow::event(QEvent *event)
{
    qDebug()<<event;
    if(event->type()==QEvent::Close)
    {
        return false;
    }
    return QMainWindow::event(event);
}

bool MyMainWindow::eventFilter(QObject *watched, QEvent *event)
{
    if(watched==(QObject *)this &&event->type()==QEvent::Close)
    {
        return true;
    }
    return QMainWindow::eventFilter(watched,event);
}
//懒的写槽函数了
void MyMainWindow::slotOpen()
{
    QString strFile=QFileDialog::getOpenFileName();
    qDebug()<<"open file is"<<strFile;
}

void MyMainWindow::slotActioned(QSystemTrayIcon::ActivationReason)//响应托盘事件
{
    if(reason==QSystemTrayIcon::Trigger)
    {
        if(this->isHidden()) this->show();
        else this->hide();
    }
}

int main(int argc,char *argv[])
{
    QApplication app(argc,argv);

    MyMainWindow w;
    w.show();
    return app.exec();
}

#include "myview.h"

MyView::MyView(QWidget *parent) : QWidget(parent)
{

}

void MyView::paintEvent(QPaintEvent *)
{
    QPainter p(this);
    p.fillRect(rect(),Qt::red);

}