两张图片合成为一张图片

- (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;  }