我是否需要释放从UIGraphicsGetCurrentContext（）返回的上下文？

CGContextRef

UIGraphicsBeginImageContext(self.drawImage.frame.size);
CGContextRef context=UIGraphicsGetCurrentContext();
CGContextSetRGBStrokeColor(context,0.0f,0.0f,0.0f,1.0f);
UIGraphicsEndImageContext();
CGContextRelease(context);

CGContextRelease(Context);