Obtain a CGContextRef of NSView outside of drawRec

问题:

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

In Carbon this thing was done like this:

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

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

Your ideas?

回答1:

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

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

also have a look to the lockFocusIfCanDraw of NSView