How to render UIView into a CGContext
I Wanted to render a UIView into a CGContextRef
-(void)methodName:(CGContextRef)ctx {
UIView *someView 开发者_StackOverflow= [[UIView alloc] init];
MagicalFunction(ctx, someView);
}
So, the MagicalFunction here is supposed to render the UIView(may be its layer) into current context.
How do I do that?
Thanks in advance!
How about the renderInContext method of CALayer?
-(void)methodName:(CGContextRef)ctx {
UIView *someView = [[UIView alloc] init];
[someView.layer renderInContext:ctx];
}
EDIT: As noted in the comment, due to a difference in origins in the two coordinate systems involved in the process, the layer will be rendered upside-down. To compensate, you just need to flip the context vertically. This is technically done with a scale and translation transformation, which can be combined in a single matrix transformation:
-(void)methodName:(CGContextRef)ctx {
UIView *someView = [[UIView alloc] init];
CGAffineTransform verticalFlip = CGAffineTransformMake(1, 0, 0, -1, 0, someView.frame.size.height);
CGContextConcatCTM(ctx, verticalFlip);
[someView.layer renderInContext:ctx];
}
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