X11: This feature relies on the use of an X server that supports ARGB visuals and a compositing window manager.
X11(linux):此特性依赖于能提供支持ARGB视觉效果和复合式视窗管理的X服务的功能开启。
windowOpacity : double
This property holds the level of opacity for the window.
The valid range of opacity is from 1.0 (completely opaque) to 0.0 (completely transparent).
By default the value of this property is 1.0.
This feature is available on Embedded Linux, Mac OS X, Windows, and X11 platforms that support the Composite extension.
This feature is not available on Windows CE.
Note that under X11 you need to have a composite manager running, and the X11 specific _NET_WM_WINDOW_OPACITY atom needs to be supported by the window manager you are using.
Warning: Changing this property from opaque to transparent might issue a paint event that needs to be processed before the window is displayed correctly. This affects mainly the use of QPixmap::grabWindow(). Also note that semi-transparent windows update and resize significantly slower than opaque windows.
x11的区别在这里:
Note that under X11 you need to have a composite manager running, and the X11 specific _NET_WM_WINDOW_OPACITY atom needs to be supported by the window manager you are using.