将一张图片绘制到另一张图片上

- (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;    
}```