How to create a UIImage from the current graphics context?

Question

I'd like to create a UIImage object from the current graphics context. More specifically, my use case is a view that the user can draw lines on. They may draw incrementally. After they are done, I'd like to create a UIImage to represent their drawing.

Here is what drawRect: looks like for me now:

- (void)drawRect:(CGRect)rect { CGContextRef c = UIGraphicsGetCurrentContext();  CGContextSaveGState(c); CGContextSetStrokeColorWithColor(c, [UIColor blackColor].CGColor); CGContextSetLineWidth(c,1.5f);  for(CFIndex i = 0; i < CFArrayGetCount(_pathArray); i++) {     CGPathRef path = CFArrayGetValueAtIndex(_pathArray, i);     CGContextAddPath(c, path); }  CGContextStrokePath(c);  CGContextRestoreGState(c); } 

... where _pathArray is of type CFArrayRef, and is populated every time touchesEnded: is invoked. Also note that drawRect: may be invoked several times, as the user draws.

When the user is done, I'd like to create a UIImage object that represents the graphics context. Any suggestions on how to do this?

Answer 1

You need to setup the graphics context first:

UIGraphicsBeginImageContext(myView.bounds.size); [myView.layer renderInContext:UIGraphicsGetCurrentContext()]; viewImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();