//  ViewController.m
//  01-图片水印
#import "ViewController.h"// 在图片的基础绘制一些文字或者Logo,最终生成一张图片
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.// 加载图片UIImage *image = [UIImage imageNamed:@"小黄人"];// 0.获取上下文，之前的上下文都是在view的drawRect方法中获取（跟View相关联的上下文layer上下文）// 目前我们需要绘制图片到新的图片上，因此需要用到位图上下文// 怎么获取位图上下文,注意位图上下文的获取方式跟layer上下文不一样。位图上下文需要我们手动创建。// 开启一个位图上下文，注意位图上下文跟view无关联，所以不需要在drawRect.// size:位图上下文的尺寸（新图片的尺寸）// opaque: 不透明度 YES：不透明 NO:透明，通常我们一般都弄透明的上下文// scale:通常不需要缩放上下文，取值为0，表示不缩放UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);// 1.获取上下文(位图上下文)CGContextRef ctx = UIGraphicsGetCurrentContext();// 2.描述路径CGContextMoveToPoint(ctx, 50, 50);CGContextAddLineToPoint(ctx, 200, 200);[[UIColor redColor] set];// 3.渲染上下文
    CGContextStrokePath(ctx);//    UIBezierPath *path =[UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 300, 300)];
//
//    [[UIColor redColor] set];
//    [path stroke];//    // 1.绘制原生的图片
//    [image drawAtPoint:CGPointZero];
//
//    // 2.给原生的图片添加文字
//    NSString *str = @"小码哥";
//
//    // 创建字典属性
//    NSMutableDictionary *dict = [NSMutableDictionary dictionary];
//    dict[NSForegroundColorAttributeName] = [UIColor redColor];
//    dict[NSFontAttributeName] = [UIFont systemFontOfSize:20];
//
//    [str drawAtPoint:CGPointMake(200, 528) withAttributes:dict];// 3.生成一张图片给我们,从上下文中获取图片UIImage *imageWater = UIGraphicsGetImageFromCurrentImageContext();// 4.关闭上下文
//    UIGraphicsEndImageContext();
    _imageView.image = imageWater;}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end

//  ViewController.m
//  02-图片裁剪
#import "ViewController.h"
#import "UIImage+Image.h"
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.// 图片裁剪：把正方形图片重新生产一张圆形的图片// 图片裁剪
    UIImage *image = [UIImage imageWithClipImage:[UIImage imageNamed:@"阿狸头像"] borderWidth:1 borderColor:[UIColor redColor]];_imageView.image = image;
}- (void)clipImage
{// 0.加载图片UIImage *image = [UIImage imageNamed:@"阿狸头像"];// 1.开启位图上下文，跟图片尺寸一样大UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);// 2.设置圆形裁剪区域，正切与图片// 2.1创建圆形的路径UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, image.size.width, image.size.height)];// 2.2把路径设置为裁剪区域
    [path addClip];// 3.绘制图片
    [image drawAtPoint:CGPointZero];// 4.从上下文中获取图片UIImage *clipImage = UIGraphicsGetImageFromCurrentImageContext();// 5.关闭上下文
    UIGraphicsEndImageContext();_imageView.image = clipImage;
}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end

//  UIImage+Image.h
//  02-图片裁剪
#import <UIKit/UIKit.h>@interface UIImage (Image)
+ (UIImage *)imageWithClipImage:(UIImage *)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)color;
@end

//  UIImage+Image.m
//  02-图片裁剪
#import "UIImage+Image.h"@implementation UIImage (Image)
+ (UIImage *)imageWithClipImage:(UIImage *)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)color
{// 图片的宽度和高度CGFloat imageWH = image.size.width;// 设置圆环的宽度CGFloat border = borderWidth;// 圆形的宽度和高度CGFloat ovalWH = imageWH + 2 * border;// 1.开启上下文UIGraphicsBeginImageContextWithOptions(CGSizeMake(ovalWH, ovalWH), NO, 0);// 2.画大圆UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, ovalWH, ovalWH)];[color set];[path fill];// 3.设置裁剪区域UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(border, border, imageWH, imageWH)];[clipPath addClip];// 4.绘制图片
    [image drawAtPoint:CGPointMake(border, border)];// 5.获取图片UIImage *clipImage = UIGraphicsGetImageFromCurrentImageContext();// 6.关闭上下文
    UIGraphicsEndImageContext();return clipImage;}@end

//  ViewController.m
//  03-屏幕截屏
#import "ViewController.h"#import "UIImage+Image.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.// 生成一张新的图片
    UIImage *image =  [UIImage imageWithCaputureView:self.view];// image转data// compressionQuality： 图片质量 1:最高质量
    NSData *data = UIImageJPEGRepresentation(image,1);[data writeToFile:@"/Users/xiaomage/Desktop/view.png" atomically:YES];}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end

//  UIImage+Image.h
//  02-图片裁剪
#import <UIKit/UIKit.h>@interface UIImage (Image)
// 圆形裁剪
+ (UIImage *)imageWithClipImage:(UIImage *)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)color;// 控件截屏
+ (UIImage *)imageWithCaputureView:(UIView *)view;@end

//  UIImage+Image.m
//  02-图片裁剪
#import "UIImage+Image.h"@implementation UIImage (Image)
+ (UIImage *)imageWithClipImage:(UIImage *)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor *)color
{// 图片的宽度和高度CGFloat imageWH = image.size.width;// 设置圆环的宽度CGFloat border = borderWidth;// 圆形的宽度和高度CGFloat ovalWH = imageWH + 2 * border;// 1.开启上下文UIGraphicsBeginImageContextWithOptions(CGSizeMake(ovalWH, ovalWH), NO, 0);// 2.画大圆UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, ovalWH, ovalWH)];[color set];[path fill];// 3.设置裁剪区域UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(border, border, imageWH, imageWH)];[clipPath addClip];// 4.绘制图片
    [image drawAtPoint:CGPointMake(border, border)];// 5.获取图片UIImage *clipImage = UIGraphicsGetImageFromCurrentImageContext();// 6.关闭上下文
    UIGraphicsEndImageContext();return clipImage;}+ (UIImage *)imageWithCaputureView:(UIView *)view
{// 开启位图上下文UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 0);// 获取上下文CGContextRef ctx = UIGraphicsGetCurrentContext();// 把控件上的图层渲染到上下文,layer只能渲染
    [view.layer renderInContext:ctx];// 生成一张图片UIImage *image = UIGraphicsGetImageFromCurrentImageContext();// 关闭上下文
    UIGraphicsEndImageContext();return image;
}@end

//  ViewController.m
//  04-图片截取
#import "ViewController.h"@interface ViewController ()@property (nonatomic, assign) CGPoint startP;@property (weak, nonatomic) IBOutlet UIImageView *imageV;
@property (nonatomic, weak) UIView *clipView;@end@implementation ViewController- (UIView *)clipView{if (_clipView == nil) {UIView *view = [[UIView alloc] init];_clipView = view;view.backgroundColor = [UIColor blackColor];view.alpha = 0.5;[self.view addSubview:view];}return _clipView;
}- (void)viewDidLoad {[super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.// 给控制器的view添加一个pan手势UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];[self.view addGestureRecognizer:pan];
}- (void)pan:(UIPanGestureRecognizer *)pan
{CGPoint endA = CGPointZero;if (pan.state == UIGestureRecognizerStateBegan) { // 一开始拖动的时候// 获取一开始触摸点_startP = [pan locationInView:self.view];}else if(pan.state == UIGestureRecognizerStateChanged){ // 一直拖动// 获取结束点endA = [pan locationInView:self.view];CGFloat w = endA.x - _startP.x;CGFloat h = endA.y - _startP.y;// 获取截取范围CGRect clipRect = CGRectMake(_startP.x, _startP.y, w, h);// 生成截屏的viewself.clipView.frame = clipRect;}else if (pan.state == UIGestureRecognizerStateEnded){// 图片裁剪，生成一张新的图片// 开启上下文// 如果不透明，默认超出裁剪区域会变成黑色，通常都是透明UIGraphicsBeginImageContextWithOptions(_imageV.bounds.size, NO, 0);// 设置裁剪区域UIBezierPath *path =  [UIBezierPath bezierPathWithRect:_clipView.frame];[path addClip];// 获取上下文CGContextRef ctx = UIGraphicsGetCurrentContext();// 把控件上的内容渲染到上下文
        [_imageV.layer renderInContext:ctx];// 生成一张新的图片_imageV.image = UIGraphicsGetImageFromCurrentImageContext();// 关闭上下文
        UIGraphicsEndImageContext();// 先移除
        [_clipView removeFromSuperview];// 截取的view设置为nil_clipView = nil;}// 获取手指的偏移量
//    pan translationInView:<#(UIView *)#>
}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end

//
//  ViewController.m
//  05-图片擦除
#import "ViewController.h"@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];[self.view addGestureRecognizer:pan];
}- (void)pan:(UIPanGestureRecognizer *)pan
{// 获取当前点CGPoint curP = [pan locationInView:self.view];// 获取擦除的矩形范围CGFloat wh = 100;CGFloat x = curP.x - wh * 0.5;CGFloat y = curP.y - wh * 0.5;CGRect rect = CGRectMake(x, y, wh, wh);// 开启上下文UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, 0);CGContextRef ctx = UIGraphicsGetCurrentContext();// 控件的layer渲染上去
    [_imageView.layer renderInContext:ctx];// 擦除图片
    CGContextClearRect(ctx, rect);// 生成一张图片UIImage *image = UIGraphicsGetImageFromCurrentImageContext();_imageView.image = image;// 关闭上下文
    UIGraphicsEndImageContext();}
- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}@end