两张图片拼成上下相接的一张图片

两张图片拼成上下相接的一张图片(曾经一次面试的题目)

-(UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 {

    //设置返回图片size(图片1的宽,图片1和2高的和)
    CGSize size = CGSizeMake(image1.size.width, image1.size.height+image2.size.height);
    
    UIGraphicsBeginImageContext(size);
    
   // Draw image1
    [image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];
    
    // Draw image2
    [image2 drawInRect:CGRectMake(0, image1.size.height, image2.size.width, image2.size.height)];
    
    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return resultingImage;
}