有些窗口在自身最小化时要在桌面上显示一个小浮标,让用户利用这个小浮标进行各种操作(例如迅雷的悬浮窗一样),我试着用QT实现一下这个功能。
PS:本来以为这个功能很简单,却搞了我两个晚上,泪奔。。。
思路:
1:制作一个由一个小图标组成的,可点击,可拖动,背景透明的Widget
2:重载主窗口(在此例子中是QLabel)的changeEvent(详情见代码)
截图:(浅绿色的部分是桌面背景)
主窗体:
小浮标:
代码:
- #include <QtGui>
- #include <Windows.h>
- //
- class MinIconWidget : public QWidget
- {
- Q_OBJECT
- private:
- QPoint m_CurrentPos;
- QPixmap m_Pixmap;
- protected:
- void mousePressEvent(QMouseEvent *event);
- void mouseMoveEvent(QMouseEvent *event);
- void paintEvent(QPaintEvent *event);
- void enterEvent(QEvent *event);
- void leaveEvent(QEvent *event);
- void mouseDoubleClickEvent(QMouseEvent *event);
- public:
- MinIconWidget(QWidget *parent = 0);
- void SetPixmap(const QPixmap &pixmap);
- signals:
- void DoubleClickedSignal();
- };
- MinIconWidget::MinIconWidget(QWidget *parent)
- : QWidget(parent)
- {
- //将浮标Widget设置为:顶层窗口;无标题栏;工具条模式;背景透明;无输入焦点
- setWindowFlags( Qt::FramelessWindowHint
- | Qt::WindowStaysOnTopHint | Qt::Tool );
- setAttribute(Qt::WA_TranslucentBackground, true);
- setFocusPolicy(Qt::NoFocus);
- }
- void MinIconWidget::mousePressEvent(QMouseEvent *event)
- {
- //按住左键移动可以拖动窗口
- if(event->button() == Qt::LeftButton)
- {
- m_CurrentPos = event->globalPos() - frameGeometry().topLeft();
- event->accept();
- }
- }
- void MinIconWidget::mouseMoveEvent(QMouseEvent *event)
- {
- if (event->buttons() && Qt::LeftButton)
- {
- move(event->globalPos() - m_CurrentPos);
- event->accept();
- }
- }
- void MinIconWidget::paintEvent(QPaintEvent *event)
- {
- QPainter painter(this);
- painter.drawPixmap(0, 0, m_Pixmap);
- }
- void MinIconWidget::leaveEvent(QEvent *event)
- {
- //鼠标离开窗口时是普通的指针
- setCursor(Qt::ArrowCursor);
- }
- void MinIconWidget::enterEvent(QEvent *event)
- {
- //鼠标留在窗口上时是一个手指
- setCursor(Qt::PointingHandCursor);
- }
- void MinIconWidget::mouseDoubleClickEvent(QMouseEvent *event)
- {
- emit DoubleClickedSignal();
- }
- void MinIconWidget::SetPixmap(const QPixmap &pixmap)
- {
- m_Pixmap = pixmap;
- update();
- }
- class MyLabel : public QLabel
- {
- Q_OBJECT
- private:
- MinIconWidget *m_minIcon;
- protected:
- void changeEvent(QEvent *event);
- public:
- MyLabel(QWidget *parent = 0);
- public slots:
- void ShowMainWindow();
- void HideMainWindow();
- };
- MyLabel::MyLabel(QWidget *parent /* = 0 */)
- : QLabel(parent)
- {
- m_minIcon = new MinIconWidget;
- m_minIcon->SetPixmap( QPixmap("delete.png") );
- setWindowFlags( Qt::WindowStaysOnTopHint );
- //双击浮动时,隐藏浮标,还原主窗口(这里是一个LABEL)
- connect(m_minIcon, SIGNAL(DoubleClickedSignal()), this, SLOT(ShowMainWindow()));
- }
- void MyLabel::changeEvent(QEvent *event)
- {
- //重点,窗口最小化时最小化窗口(废话),显示浮标
- //窗口还原时,隐藏浮标,还原主窗口(这里是一个LABEL)
- if(event->type()==QEvent::WindowStateChange)
- {
- //changeEvent会在窗口最小化之前调用,如果不加QTimer,
- //我们把窗口隐藏了,但是Qt还以为窗口正要最小化,这样就会出错
- if(windowState() & Qt::WindowMinimized)
- QTimer::singleShot(0, this, SLOT(HideMainWindow()));
- else if(windowState() & Qt::WindowNoState)
- QTimer::singleShot(0, this, SLOT(ShowMainWindow()));
- }
- QLabel::changeEvent(event);
- }
- void MyLabel::ShowMainWindow()
- {
- m_minIcon->hide();
- move( m_minIcon->pos() );
- show();
- setWindowState(Qt::WindowNoState);
- }
- void MyLabel::HideMainWindow()
- {
- hide();
- m_minIcon->move( pos() );
- m_minIcon->show();
- setWindowState(Qt::WindowMinimized);
- }
- #include "main.moc"
- int main(int argc, char **argv)
- {
- QApplication app(argc, argv);
- MyLabel label;
- label.setStyleSheet("QLabel{font-size:30px;color:red;}");
- label.resize(400, 200);
- label.setText("This is a simple demo.");
- label.show();
- return app.exec();
- }
http://blog.csdn.net/small_qch/article/details/7761139