给图片加水印

Posted on 2016-07-12 17:10  柠檬片  阅读(147)  评论(0)    收藏  举报 
 1 - (void)viewDidLoad {
 2     [super viewDidLoad];
 3     // Do any additional setup after loading the view, typically from a nib.
 4     
 5     UIImage *image = [UIImage imageNamed:@"卡哇伊"];
 6     
 7     //生成图片.
 8     //size:开开启一个多大图片上下文.
 9     //opaque:不透度
10     //scale:0
11     //开启跟图片相同的大小上下文.
12     UIGraphicsBeginImageContextWithOptions(image.size, NO, 0.0);
13     //把图片给绘制图片上下文.
14     [image drawAtPoint:CGPointZero];
15     //绘制文字
16     NSString *str = @"小码哥";
17     [str drawAtPoint:CGPointZero withAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:20]}];
18     //生成图片
19     UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
20     //手动关闭上下文
21     UIGraphicsEndImageContext();
22 
23     self.imageV.image = newImage;
24     
25     
26 }
给图片加水印