iphone 中两张图合为一张图片

- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 { UIGraphicsBeginImageContext(image1.size);   // Draw image1 [image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];   // Draw image2 [image2 drawInRect:CGRectMake(0, 0, image2.size.width, image2.size.height)];   UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();   UIGraphicsEndImageContext();   return resultingImage; }