使用QT实现可以拖动的按钮

效果演示

实现步骤

思路：
创建DragPushButton类继承自QPushButton，重写mousePressEvent和mouseMoveEvent方法。

1. dragpushbutton.h文件

#ifndef DRAGPUSHBUTTON_H
#define DRAGPUSHBUTTON_H

#include <QWidget>
#include <QPushButton>
#include <QMouseEvent>
#include <QDebug>

class DragPushButton : public QPushButton
{
    Q_OBJECT
public:
    explicit DragPushButton(QWidget *parent = nullptr);

protected:
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);

private:
    QPoint pressPoint;
};

#endif // DRAGPUSHBUTTON_H

2. dragpushbutton.cpp文件

#pragma execution_character_set("utf-8")
#include "dragpushbutton.h"

DragPushButton::DragPushButton(QWidget *parent) : QPushButton(parent){}

void DragPushButton::mousePressEvent(QMouseEvent *event)
{
    if(event->button() == Qt::LeftButton){
        this->raise(); //将此按钮移动到顶层显示
        this->pressPoint = event->pos();
    }
}

void DragPushButton::mouseMoveEvent(QMouseEvent *event)
{
    if(event->buttons() == Qt::LeftButton){
        this->move(this->mapToParent(event->pos() - this->pressPoint));

        //防止按钮移出父窗口
        if(this->mapToParent(this->rect().topLeft()).x() <= 0){
            this->move(0, this->pos().y());
        }
        if(this->mapToParent(this->rect().bottomRight()).x() >= this->parentWidget()->rect().width()){
            this->move(this->parentWidget()->rect().width() - this->width(), this->pos().y());
        }
        if(this->mapToParent(this->rect().topLeft()).y() <= 0){
            this->move(this->pos().x(), 0);
        }
        if(this->mapToParent(this->rect().bottomRight()).y() >= this->parentWidget()->rect().height()){
            this->move(this->pos().x(), this->parentWidget()->rect().height() - this->height());
        }
    }
}