windows 使用 Qt 显示半透明/不规则形状的窗口
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Displaying translucent / irregular-shaped windows with Qt
提问by Tony the Pony
Is it possible to display translucent and/or irregular-shaped windows with Qt?
是否可以使用 Qt 显示半透明和/或不规则形状的窗口？
(I'm assuming it ultimately depends on the capabilities of the underlying GUI system, but let's assume at least Windows XP / Mac OS X)
（我假设它最终取决于底层 GUI 系统的功能，但让我们假设至少是 Windows XP / Mac OS X）
If so, how does one accomplish this?
如果是这样，如何实现这一目标？
采纳答案by 0xced
Yes, it is possible. The key is the Qt::WA_TranslucentBackgroundattribute of QWidget
对的，这是可能的。关键是Qt::WA_TranslucentBackground属性QWidget
Here is a simple class that draws a round translucent window with a red background 50% alpha.
这是一个简单的类，它绘制一个带有红色背景 50% alpha 的圆形半透明窗口。
TranslucentRoundWindow.h:
半透明圆形窗口.h：
#include <QWidget>
class TranslucentRoundWindow : public QWidget
{
public:
TranslucentRoundWindow(QWidget *parent = 0);
virtual QSize sizeHint() const;
protected:
virtual void paintEvent(QPaintEvent *paintEvent);
};
TranslucentRoundWindow.cpp:
半透明圆形窗口.cpp：
#include <QtGui>
#include "TranslucentRoundWindow.h"
TranslucentRoundWindow::TranslucentRoundWindow(QWidget *parent) : QWidget(parent, Qt::FramelessWindowHint)
{
setAttribute(Qt::WA_TranslucentBackground);
}
QSize TranslucentRoundWindow::sizeHint() const
{
return QSize(300, 300);
}
void TranslucentRoundWindow::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.setPen(Qt::NoPen);
painter.setBrush(QColor(255, 0, 0, 127));
painter.drawEllipse(0, 0, width(), height());
}
If you want to be able to move this window with the mouse, you will have to override mousePressEvent, mouseMoveEventand mouseReleaseEvent.
如果您希望能够用鼠标移动此窗口，则必须覆盖mousePressEvent,mouseMoveEvent和mouseReleaseEvent。
