两张图片的合并处理

- (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;  
}