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UIImage+MJ.h
#import <UIKit/UIKit.h> @interface UIImage (MJ) /** * 打水印 * * @param bg 背景图片 * @param logo 右下角的水印图片 */ + (instancetype)waterImageWithBg:(NSString *)bg logo:(NSString *)logo; @end
UIImage+MJ.m
#import "UIImage+MJ.h" @implementation UIImage (MJ) + (instancetype)waterImageWithBg:(NSString *)bg logo:(NSString *)logo { UIImage *bgImage = [UIImage imageNamed:bg]; // 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) UIGraphicsBeginImageContextWithOptions(bgImage.size, NO, 0.0); // 2.画背景 [bgImage drawInRect:CGRectMake(0, 0, bgImage.size.width, bgImage.size.height)]; // 3.画右下角的水印 UIImage *waterImage = [UIImage imageNamed:logo]; CGFloat scale = 0.2; CGFloat margin = 5; CGFloat waterW = waterImage.size.width * scale; CGFloat waterH = waterImage.size.height * scale; CGFloat waterX = bgImage.size.width - waterW - margin; CGFloat waterY = bgImage.size.height - waterH - margin; [waterImage drawInRect:CGRectMake(waterX, waterY, waterW, waterH)]; // 4.从上下文中取得制作完毕的UIImage对象 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); // 5.结束上下文 UIGraphicsEndImageContext(); return newImage; } @end
使用方式
- (void)viewDidLoad { [super viewDidLoad]; // 1.返回水印图片 UIImage *newImage = [UIImage waterImageWithBg:@"scene" logo:@"logo"]; // 2.显示图片 self.iconView.image = newImage; // 3.将image对象压缩为PNG格式的二进制数据 NSData *data = UIImagePNGRepresentation(newImage); // 4.写入文件 NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"new.png"]; [data writeToFile:path atomically:YES]; }
UIImage+MJ.h
#import <UIKit/UIKit.h> @interface UIImage (MJ) + (instancetype)circleImageWithName:(NSString *)name borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)borderColor; @end
UIImage+MJ.m
#import "UIImage+MJ.h" @implementation UIImage (MJ) + (instancetype)circleImageWithName:(NSString *)name borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)borderColor { // 1.加载原图 UIImage *oldImage = [UIImage imageNamed:name]; // 2.开启上下文 CGFloat imageW = oldImage.size.width + 2 * borderWidth; CGFloat imageH = oldImage.size.height + 2 * borderWidth; CGSize imageSize = CGSizeMake(imageW, imageH); UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0); // 3.取得当前的上下文 CGContextRef ctx = UIGraphicsGetCurrentContext(); // 4.画边框(大圆) [borderColor set]; CGFloat bigRadius = imageW * 0.5; // 大圆半径 CGFloat centerX = bigRadius; // 圆心 CGFloat centerY = bigRadius; CGContextAddArc(ctx, centerX, centerY, bigRadius, 0, M_PI * 2, 0); CGContextFillPath(ctx); // 画圆 // 5.小圆 CGFloat smallRadius = bigRadius - borderWidth; CGContextAddArc(ctx, centerX, centerY, smallRadius, 0, M_PI * 2, 0); // 裁剪(后面画的东西才会受裁剪的影响) CGContextClip(ctx); // 6.画图 [oldImage drawInRect:CGRectMake(borderWidth, borderWidth, oldImage.size.width, oldImage.size.height)]; // 7.取图 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); // 8.结束上下文 UIGraphicsEndImageContext(); return newImage; } @end
使用方法:
- (void)viewDidLoad { [super viewDidLoad]; UIImage *newImage = [UIImage circleImageWithName:@"me" borderWidth:3 borderColor:[UIColor whiteColor]]; self.iconView.image = newImage; NSData *data = UIImagePNGRepresentation(newImage); NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"new.png"]; [data writeToFile:path atomically:YES]; }
效果
UIImage+MJ.h
#import <UIKit/UIKit.h> @interface UIImage (MJ) + (instancetype)captureWithView:(UIView *)view; @end
UIImage+MJ.m
#import "UIImage+MJ.h" @implementation UIImage (MJ) + (instancetype)captureWithView:(UIView *)view { // 1.开启上下文 UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0); // 2.将控制器view的layer渲染到上下文 [view.layer renderInContext:UIGraphicsGetCurrentContext()]; // 3.取出图片 UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); // 4.结束上下文 UIGraphicsEndImageContext(); return newImage; } @end
使用方法
- (IBAction)clip { dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ // 1.捕捉 UIImage *newImage = [UIImage captureWithView:self.view]; // 2.写文件 NSData *data = UIImagePNGRepresentation(newImage); NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"new.png"]; [data writeToFile:path atomically:YES]; }); }
iOS UI进阶-1.1 Quartz2D 图片水印/裁剪/截图
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原文地址:http://www.cnblogs.com/jys509/p/4843739.html