Working with UIGraphicsPushContext(aContext) and UIGraphicsPopContext() - objective-c

Question

I'm having problems getting the subject calls to work. The below test should draw two orange and one green rectangle.
Here is my understanding of the below code...
I draw a orange rectangle at 50,50
I call the draw greenRect at 200,200, sending the current context
I push the current context on the stack, change the stroke color and draw a green rect at 100,100
I pop the current context which should restore the original context (orange stroke color)
I then draw the last rectangle which should be stroking orange
The last rectangle should stroke orange, but is stroking green, telling me that I modified the original context
Thoughts?
- (void)drawRect:(CGRect)rect{
CGRect aRectangle=CGRectMake(50., 50., 40., 40.);
UIBezierPath *path=[UIBezierPath bezierPathWithRect:aRectangle];
UIColor *strokeColor=[UIColor orangeColor];
[strokeColor setStroke];
[path stroke];
CGContextRef context=UIGraphicsGetCurrentContext();
[self drawGreenRect:context];
CGRect anotherRectangle=CGRectMake(100., 100., 40., 40.);
UIBezierPath *anotherPath=[UIBezierPath bezierPathWithRect:anotherRectangle];
[anotherPath stroke];
}
- (void)drawGreenRect:(CGContextRef)ctxt{
UIGraphicsPushContext(UIGraphicsGetCurrentContext());
CGRect aRectangle=CGRectMake(200., 200., 40., 40.);
UIBezierPath *path=[UIBezierPath bezierPathWithRect:aRectangle];
UIColor *strokeColor=[UIColor greenColor];
[strokeColor setStroke];
[path stroke];
UIGraphicsPopContext();
}

Answer 1

UIGraphicsPushContext() doesn't create a new context for you, it just pushes the context you pass onto a stack. So after you do UIGraphicsPushContext(UIGraphicsGetCurrentContext());, you've got a graphics context stack two deep, but both of the items on it are the same context, the one that was set up by your view for you.
You'll need to actually create a context to push, most likely using UIGraphicsBeginImageContext(). You can then get the image from that context and put it into your view.