如何使用 CGContext 获取全局（屏幕、设备）坐标？
我尝试为 Mac OSX 中的浏览器制作一个插件。
我从浏览器进程中获得了 CGContext 。
所以我可以用它画画。
我要做的就是制作一个用于事件处理的窗口，有人在这个令人惊叹的网站中向我建议:)
我可以轻松制作一个透明窗口，但我可以将该窗口移动到适当的位置。
我确切地知道窗口的大小，但我可以确定窗口的原点。
我唯一得到的是 CGContextRef。
我试过这个。
NSRect rect = [mywindow frame];
CGPoint origin;
origin.x = rect.origin.x;
origin.y = rect.origin.y;
CGPoint globalOrigin = CGContextConvertPointToDeviceSpace(cgContext, origin);
if (globalOrigin.x != origin.x || globalOrigin.y != origin.y) {
NSPoint newPoint;
newPoint.x = globalOrigin.x;
newPoint.y = globalOrigin.y;
[mywindow setFrameOrigin:newPoint];
}
但没有运气。它返回了我给它的值 有
什么建议吗？
提前致谢。
I try to make a plugin for browsers in Mac OSX.
I got a CGContext from browser process.
So I can draw with it.
What I have to do is make a window for event handling someone advise me in this amazing site :)
I can make a transparent window easily but I can move that window proper position.
I know the size of window exactly but I can determine the origin of window.
Only thing I got is CGContextRef.
I tried this.
NSRect rect = [mywindow frame];
CGPoint origin;
origin.x = rect.origin.x;
origin.y = rect.origin.y;
CGPoint globalOrigin = CGContextConvertPointToDeviceSpace(cgContext, origin);
if (globalOrigin.x != origin.x || globalOrigin.y != origin.y) {
NSPoint newPoint;
newPoint.x = globalOrigin.x;
newPoint.y = globalOrigin.y;
[mywindow setFrameOrigin:newPoint];
}
But no luck. It returned the value what I gave it to
Any advice?
Thanks in advance.
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评论（2）
您在 NPAPI 插件中获得的 CGContext 不一定与任何窗口关联，因此不可能从 CGContext 映射到屏幕上的位置。
The CGContext you get in an NPAPI plugin is not necessarily associated with any window, so it's impossible to map from the CGContext to a location on screen.
斯摩根的回答是正确的。
对于可能需要更多解释的人，我将添加我的想法。
我认为插件进程有 CGContext，它没有真正的操作系统窗口。因为浏览器进程需要窗口，而插件进程只是将绘图数据传输到浏览器进程，所以插件进程的 CGContext 没有位置。它可能只是内存缓冲区。
谢谢斯摩根。
smorgan's answer is right.
For someone who maybe need more explanations, I will add my thinking.
I think plugin process has CGContext which doesn't have real os window. because browser process need window but plugin process just transfer drawing data to browser process, so plugin process's CGContext does NOT have location. It might be just memory buffer.
Thanks smorgan.