在drawRect外获得NSView的CGContextRef？ [英] Obtain a CGContextRef of NSView outside of drawRect?

问题描述

我需要获得NSView对象的CGContextRef。

I need to get CGContextRef of NSView object. It won't be so bad if I knew how.

在Carbon这个东西是这样做的：

In Carbon this thing was done like this:

CGContextRef cgref = (libvlc_drawable_t)GetWindowPort(HIViewGetWindow((OpaqueControlRef*)hiViewRef));

显然，它可以通过子类化NSView（或它的子类），并捕获它的drawRect，

Obviously it can be done by subclassing NSView (or it's subclass) and catching it in it's drawRect, but that's too ugly.

您的想法？

推荐答案

从未使用它，但它认为这是你的方式：

I've never used it but it think this is your way:

[myView lockFocus];
imageContext = (CGContextRef)[[NSGraphicsContext currentContext]
                                     graphicsPort];
... 
[myView unlockFocus];

也可以看看NSView的lockFocusIfCanDraw

also have a look to the lockFocusIfCanDraw of NSView

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