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图片水印功能
1 #import "UIImage+ZR.h" 2 3 @implementation UIImage (ZR) 4 + (instancetype)waterImageWithBg:(NSString *)bg logo:(NSString *)logo 5 { 6 UIImage *bgImage = [UIImage imageNamed:bg]; 7 8 // 1.创建一个基于位图的上下文(开启一个基于位图的上下文) 9 UIGraphicsBeginImageContextWithOptions(bgImage.size, NO, 0.0); 10 11 // 2.画背景 12 [bgImage drawInRect:CGRectMake(0, 0, bgImage.size.width, bgImage.size.height)]; 13 14 // 3.画右下角的水印 15 UIImage *waterImage = [UIImage imageNamed:logo]; 16 CGFloat scale = 0.2; 17 CGFloat margin = 5; 18 CGFloat waterW = waterImage.size.width * scale; 19 CGFloat waterH = waterImage.size.height * scale; 20 CGFloat waterX = bgImage.size.width - waterW - margin; 21 CGFloat waterY = bgImage.size.height - waterH - margin; 22 [waterImage drawInRect:CGRectMake(waterX, waterY, waterW, waterH)]; 23 24 // 4.从上下文中取得制作完毕的UIImage对象 25 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 26 27 // 5.结束上下文 28 UIGraphicsEndImageContext(); 29 30 return newImage; 31 } 32 @end
图片裁剪
1 #import "UIImage+ZR.h" 2 3 @implementation UIImage (ZR) 4 + (instancetype)circleImageWithName:(NSString *)name borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)borderColor 5 { 6 // 1.加载原图 7 UIImage *oldImage = [UIImage imageNamed:name]; 8 9 // 2.开启上下文 10 CGFloat imageW = oldImage.size.width + 2 * borderWidth; 11 CGFloat imageH = oldImage.size.height + 2 * borderWidth; 12 CGSize imageSize = CGSizeMake(imageW, imageH); 13 UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0); 14 15 // 3.取得当前的上下文 16 CGContextRef ctx = UIGraphicsGetCurrentContext(); 17 18 // 4.画边框(大圆) 19 [borderColor set]; 20 CGFloat bigRadius = imageW * 0.5; // 大圆半径 21 CGFloat centerX = bigRadius; // 圆心 22 CGFloat centerY = bigRadius; 23 CGContextAddArc(ctx, centerX, centerY, bigRadius, 0, M_PI * 2, 0); 24 CGContextFillPath(ctx); // 画圆 25 26 // 5.小圆 27 CGFloat smallRadius = bigRadius - borderWidth; 28 CGContextAddArc(ctx, centerX, centerY, smallRadius, 0, M_PI * 2, 0); 29 // 裁剪(后面画的东西才会受裁剪的影响) 30 CGContextClip(ctx); 31 32 // 6.画图 33 [oldImage drawInRect:CGRectMake(borderWidth, borderWidth, oldImage.size.width, oldImage.size.height)]; 34 35 // 7.取图 36 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 37 38 // 8.结束上下文 39 UIGraphicsEndImageContext(); 40 41 return newImage; 42 } 43 @end
屏幕截图
1 #import "UIImage+ZR.h" 2 3 @implementation UIImage (ZR) 4 + (instancetype)captureWithView:(UIView *)view 5 { 6 // 1.开启上下文 7 UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0); 8 9 // 2.将控制器view的layer渲染到上下文 10 [view.layer renderInContext:UIGraphicsGetCurrentContext()]; 11 12 // 3.取出图片 13 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 14 15 // 4.结束上下文 16 UIGraphicsEndImageContext(); 17 18 return newImage; 19 } 20 @end
背景拉伸
1 - (void)imageBg 2 { 3 UIImage *oldImage = [UIImage imageNamed:@"me"]; 4 5 UIGraphicsBeginImageContextWithOptions(self.view.frame.size, NO, 0.0); 6 [oldImage drawInRect:self.view.bounds]; 7 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 8 UIGraphicsEndImageContext(); 9 10 self.view.backgroundColor = [UIColor colorWithPatternImage:newImage]; 11 }
背景平铺
1 - (void)viewDidLoad 2 { 3 [super viewDidLoad]; 4 5 // self.view.backgroundColor = [UIColor redColor]; 6 7 // 1.创建一行背景图片 8 CGFloat rowW = self.view.frame.size.width; 9 // CGFloat rowH = 40; 10 CGFloat rowH = 30; 11 UIGraphicsBeginImageContextWithOptions(CGSizeMake(rowW, rowH), NO, 0.0); 12 13 CGContextRef ctx = UIGraphicsGetCurrentContext(); 14 // 画矩形框 15 [[UIColor redColor] set]; 16 CGContextAddRect(ctx, CGRectMake(0, 0, rowW, rowH)); 17 CGContextFillPath(ctx); 18 19 // 2.画线 20 [[UIColor greenColor] set]; 21 CGFloat lineWidth = 2; 22 CGContextSetLineWidth(ctx, lineWidth); 23 CGFloat dividerX = 0; 24 CGFloat dividerY = rowH - lineWidth; 25 CGContextMoveToPoint(ctx, dividerX, dividerY); 26 CGContextAddLineToPoint(ctx, rowW - dividerX, dividerY); 27 CGContextStrokePath(ctx); 28 29 // 3.取图 30 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); 31 32 // 4.结束上下文 33 UIGraphicsEndImageContext(); 34 35 // 5.设置为背景 36 self.textView.backgroundColor = [UIColor colorWithPatternImage:newImage]; 37 }
iOS UIImage 图片水印,图片裁剪,屏幕截图,背景平铺
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原文地址:http://www.cnblogs.com/airy99/p/4243578.html