QT学习笔记 — 移动无边框窗体

一般Qt窗体都是有边框的，通过按住上方的边框进行移动窗体位置。无边框的窗体没有边框无法移动，需要编程程序使其能移动，这就要用到那几个鼠标事件。

程序

class Widget : public QWidget
{
    
    
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();
    void closeWin();
protected:
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void mouseReleaseEvent(QMouseEvent *event);
private:
    Ui::Widget *ui;
    QPushButton *btClose;
    QPoint last;
};

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    
    
    ui->setupUi(this);
    this->setWindowTitle("移动无边框窗体");
    this->setWindowFlags(Qt::FramelessWindowHint);   //设置窗体为无边框
    setStyleSheet("background:white");   //设置窗体的背景色
    btClose = new QPushButton(this);
    btClose->setText("X");
    btClose->setGeometry(0, 0, 30, 30);
    connect(this->btClose, &QPushButton::clicked, this, &Widget::closeWin);
}

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

void Widget::closeWin()
{
    
    
    this->close();
}
//鼠标按下事件
void Widget::mousePressEvent(QMouseEvent *event)
{
    
    
    last = event->globalPos();  //获取按下时的坐标，全局坐标
}
//鼠标移动事件
void Widget::mouseMoveEvent(QMouseEvent *event)
{
    
    
    int dx = event->globalX() - last.x();   //
    int dy = event->globalY() - last.y();

    last = event->globalPos();
    move(x()+dx, y()+dy);            //移动窗体
}
//鼠标释放事件可以有也可以没有
void Widget::mouseReleaseEvent(QMouseEvent *event)
{
    
    
    int dx = event->globalX() - last.x();
    int dy = event->globalY() - last.y();
    move(x()+dx, y()+dy);
}