Qt實現窗口拖動

1.聲明變量與鼠標事件
QPoint move_point; //移動的距離
bool mouse_press; //鼠標按下
//鼠標按下事件
void mousePressEvent(QMouseEvent *event);
//鼠標釋放事件
void mouseReleaseEvent(QMouseEvent *event);
//鼠標移動事件
void mouseMoveEvent(QMouseEvent *event);

2.定義鼠標事件
void LoginDialog::mousePressEvent(QMouseEvent *event)
{

if(event->button() == Qt::LeftButton)

{

mouse_press = true;

//鼠標相對於窗體的位置（或者使用event->globalPos() - this->pos()）

move_point = event->pos();;

}

}

//=======================================================
void LoginDialog::mouseMoveEvent(QMouseEvent *event)
{
//若鼠標左鍵被按下

if(mouse_press)

{

//鼠標相對於屏幕的位置

QPoint move_pos = event->globalPos();

//移動主窗體位置

this->move(move_pos - move_point);

}

}

//=======================================================
void LoginDialog::mouseReleaseEvent(QMouseEvent *event)
{
//設置鼠標爲未被按下
mouse_press = false;
}