IOS 两个图片合并成一张图片

- (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;  
}