iOS-图片水印,图片裁剪和屏幕截图

一.图片水印

1.创建个UIImageView @property (weak, nonatomic) IBOutlet UIImageView *neImage;

2.创建个方法实现水印功能

• (void)viewDidLoad { [super viewDidLoad]; UIImage *bgImage = [UIImage imageNamed:@""]; //创建一个位图上下文
  UIGraphicsBeginImageContextWithOptions(bgImage.size, NO, 0.0); //将背景图片画入位图中 [bgImage drawInRect:CGRectMake(0, 0, bgImage.size.width, bgImage.size.height)]; //将水印Logo画入背景图中
  UIImage *waterIma = [UIImage imageNamed:@""]; [waterIma drawInRect:CGRectMake(bgImage.size.width - 40 - 5, bgImage.size.height - 40 - 5, 40, 40)]; //取得位图上下文中创建的新的图片 UIImage *newimage = UIGraphicsGetImageFromCurrentImageContext(); //结束上下文 UIGraphicsEndImageContext(); //在创建的ImageView上显示出新图片
  self.neImage.image = newimage; //压缩新照片为PNG格式的二进制数据 NSData *data = UIImagePNGRepresentation(newimage); //将图片写入到手机存储中 NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"new.png"]; [data writeToFile:path atomically:YES];

  }

二.图片裁剪

1.加载原图 UIImage *oldImage = [UIImage imageNamed:@"me"];

2.获取位图上下文 CGFloat bigCic = oldImage.size.width + 2 * 2; UIGraphicsBeginImageContextWithOptions(CGSizeMake(bigCic, bigCic), NO, 0.0);

3.画大圆 [[UIColor whiteColor] set]; CGContextRef ctx = UIGraphicsGetCurrentContext(); CGContextAddArc(ctx, bigCic * 0.5, bigCic * 0.5, bigCic * 0.5, 0, M_PI * 2, 0); CGContextFillPath(ctx);

4.画小圆 CGFloat smallCic = oldImage.size.width * 0.5; CGContextAddArc(ctx, bigCic * 0.5 , bigCic * 0.5, smallCic, 0, M_PI * 2, 0); CGContextClip(ctx);

5.画图 [oldImage drawInRect:CGRectMake(2, 2, oldImage.size.width, oldImage.size.height)];

6.获取新图 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

7.结束上下文 UIGraphicsEndImageContext();

8.显示新图 self.IconView.image = newImage;

9.写入到手机存储 NSData *data = UIImagePNGRepresentation(newImage); NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"newClip.png"];

[data writeToFile:path atomically:YES];

三,屏幕截图

1.开启位图上下文UIGraphicsBeginImageContextWithOptions(self.view.frame.size, NO, 0.0);

2.渲染截图[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];

3.获取新图UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

4.写入到手机存储NSData *data = UIImagePNGRepresentation(newImage);NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"newClip.png"];[data writeToFile:path atomically:YES];

5.关闭上下文UIGraphicsEndImageContext();