Qt实现窗口整体拖拽功能.

我们都知道，当我们鼠标点击并移动应用程序的上边框时，窗口才会整体移动，但有些窗口，你点击移动其他部分，也可以让窗口跟着鼠标移动，这里就教你如何整体移动窗口.

其实实现这样的功能很简单，只需要重写以下的3个鼠标函数即可.

//"c.h"
#ifndef C_H
#define C_H

#include <QtWidgets/QWidget>
#include "ui_c.h"
#include <QMouseEvent>

class c : public QWidget
{
Q_OBJECT

public:
c(QWidget *parent = 0);
~c();

protected:
void mousePressEvent(QMouseEvent *event);
void mouseMoveEvent(QMouseEvent *event);
void mouseReleaseEvent(QMouseEvent *event);
private:
Ui::cClass ui;
bool m_move;
QPoint m_startPoint;
QPoint m_windowPoint;
};

#endif // C_H

//"c.cpp"
#include "c.h"

c::c(QWidget *parent)
: QWidget(parent)
{
ui.setupUi(this);
//给是否移动的标志初始化为false.
m_move = false;
}

c::~c()
{

}
void c::mousePressEvent(QMouseEvent *event)
{
//当鼠标左键点击时.
if (event->button() == Qt::LeftButton)
{
m_move = true;
//记录鼠标的世界坐标.
m_startPoint = event->globalPos();
//记录窗体的世界坐标.
m_windowPoint = this->frameGeometry().topLeft();
}
}
void c::mouseMoveEvent(QMouseEvent *event)
{
if (event->buttons() & Qt::LeftButton)
{
//移动中的鼠标位置相对于初始位置的相对位置.
QPoint relativePos = event->globalPos() - m_startPoint;
//然后移动窗体即可.
this->move(m_windowPoint + instance);
}
}
void c::mouseReleaseEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton)
{
//改变移动状态.
m_move = false;
}
}