如何 合并两个UIImage 生产一个UIImage：
1、准备两个UIImage
UIImage * image1 = [UIImage imageNamed:@"1.jpg"];UIImage * image2 = [UIImage imageNamed:@"2.jpg"];
2、指定合并后UIImage的大小
CGSize size = CGSizeMake(400, 200);
3、创建一个基于位图的上下文UIGraphicsBeginImageContext（size）,并将其设置为当前上下文(context)
//上下文UIGraphicsBeginImageContext(size);
4、绘制图形，给定每个图片绘制的frame
[image1 drawInRect:CGRectMake(0, 0, 100,200)];[image2 drawInRect:CGRectMake(100, 0, 100, 200)];
5、通过此上下文生产新的UIImage
UIImage * togetherImage = UIGraphicsGetImageFromCurrentImageContext();//结束上下文UIGraphicsEndImageContext();
6、此时可以将图像展示出来啦
UIImageView * imgV = [[UIImageView alloc]initWithImage:togetherImage];imgV.center = CGPointMake(SCREEN_SIZE.width/2.0, SCREEN_SIZE.height/2.0);[self.view addSubview:imgV];
效果如下：
