图片水印.擦除 图片截屏.........

画板

#import "DrawView.h"

@interface DrawView ()
@property(nonatomic,retain)NSMutableArray * paths;
@property(nonatomic,retain)UIBezierPath *path;
@end
@implementation DrawView
-(NSMutableArray*)paths
{
    if (!_paths)
    {
        _paths=[NSMutableArray array];
    }
    return _paths;
}
-(instancetype)initWithFrame:(CGRect)frame
{
    if (self==[super initWithFrame:frame])
    {
        UIPanGestureRecognizer*pan=[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)];
        [self addGestureRecognizer:pan];
    }
    return self;
}
-(void)pan:(UIPanGestureRecognizer*)pan
{
    //获取当前手指触摸点
    CGPoint currentP = [pan locationInView:self];
    //获取开始点
    if (pan.state == UIGestureRecognizerStateBegan)
    {
        _path = [UIBezierPath bezierPath];
        //设置路径的起点
        [_path moveToPoint:currentP];
        //保存描述好的路径
        [self.paths addObject:_path];
    }
    // 手指拖动 添加线到当前触摸点
    [_path addLineToPoint:currentP];
    //重绘
    [self setNeedsDisplay];
}
//只要调用这个方法，就会把之前绘制的东西全部清掉，重新绘制
- (void)drawRect:(CGRect)rect
{
    for (UIBezierPath*path in self.paths)
    {
        [path stroke];
    }
    
}

图片裁剪

@interface CompanyViewController ()
@property(nonatomic,retain)UIImageView*imageView;
@property(nonatomic,assign)CGPoint startP;
@property(nonatomic,retain)UIView*clipView;
@end

@implementation CompanyViewController
- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor whiteColor];
    self.title=@"图片裁剪";
    _imageView=[[UIImageView alloc]initWithFrame:self.view.bounds];
    _imageView.image=[UIImage imageNamed:@"qidong"];
    [self.view addSubview:_imageView];
    _clipView=[[UIView alloc]init];
    _clipView.backgroundColor=[[UIColor blackColor] colorWithAlphaComponent:0.3];
    [self.view addSubview:_clipView];
    UIPanGestureRecognizer*pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)];
    [self.view addGestureRecognizer:pan];
}
-(void)pan:(UIPanGestureRecognizer*)pan
{
    if (pan.state == UIGestureRecognizerStateBegan)
    {
        _startP = [pan locationInView:_imageView];
    }
    else if (pan.state == UIGestureRecognizerStateChanged)
    {
        CGPoint endA = [pan locationInView:_imageView];
        
        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view
        self.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(_imageView.bounds.size, NO, 0);
        //设置裁剪区域
        UIBezierPath *path = [UIBezierPath bezierPathWithRect:_clipView.frame];
        
        [path addClip];
        
        //获取上下文
        CGContextRef context = UIGraphicsGetCurrentContext();
        
        //把控件上的内容渲染到上下文
        [_imageView.layer renderInContext:context];
        
        //生成一张新的图片
        _imageView.image = UIGraphicsGetImageFromCurrentImageContext();
        //关闭
        UIGraphicsEndImageContext();
        
    }
    
}

图片擦除

@interface CompanyViewController ()
@property(nonatomic,retain)UIImageView*imageView;
@end

@implementation CompanyViewController
- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor whiteColor];
    self.title=@"图片水印";
    _imageView=[[UIImageView alloc]initWithFrame:self.view.bounds];
    _imageView.image=[UIImage imageNamed:@""];
    [self.view addGestureRecognizer:_imageView];
    UIPanGestureRecognizer*pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)];
    [self.view addGestureRecognizer:pan];
}
-(void)pan:(UIPanGestureRecognizer*)pan
{
    //获取当前点
    CGPoint curentP = [pan locationInView:self.view];
    //获取擦除的矩形范围
    CGFloat wh = 30;
    CGFloat x  = curentP.x - wh*0.5;
    CGFloat y  = curentP.y - wh*0.5;
    
    CGRect rect = CGRectMake(x, y, wh, wh);
    //开启上下文
    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, 0);
    //获取上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    //控件的layer渲染上去
    [_imageView.layer renderInContext:context];
    //擦除图片
    CGContextClearRect(context, rect);
    //生存一张图片
    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
    _imageView.image = image;
    
    //关闭上下文
    UIGraphicsEndImageContext();
}

方形图片生产圆形头像

+(UIImage*)imageWithCilpImage:(UIImage*)image borderWidth:(CGFloat)borderWidth borderColor:(UIColor*)color
{
    //图片的宽度和高度
    CGFloat imageWH = image.size.width;
    
    //圆形的宽度和高度
    CGFloat ovalWH = imageWH + 2*borderWidth;
    
    //开启上下文
    UIGraphicsBeginImageContextWithOptions(CGSizeMake(ovalWH, ovalWH), NO, 0);
    
    //画大圆
    UIBezierPath * path=[UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, ovalWH, ovalWH)];
    //设置圆环颜色
    [color set];
    //颜色填充
    [path fill];
    //设置裁剪区域
    UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(borderWidth, borderWidth, imageWH, imageWH)];
    //图片剪切
    [clipPath addClip];
    //绘制图片
    [image drawAtPoint:CGPointMake(borderWidth, borderWidth)];
    
    //获取图片
    UIImage *clipImage = UIGraphicsGetImageFromCurrentImageContext();
    //关闭上下文
    UIGraphicsEndImageContext();
    
    return clipImage;
}

手机截屏

+(UIImage*)imageWithCaputureView:(UIView*)view
{
    //开启位图上下文
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 0);
    //获取上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    //把控件上的图层渲染到上下文,layer只能渲染
    [view.layer renderInContext:context];
    //生成一张图片
    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
    //关闭上下文
    UIGraphicsEndImageContext();
    
    return image;
}

图片水印

+(UIImage*)imageWithWaterImage:(UIImage*)image waterTitle:(NSString*)title waterAttributes:(NSDictionary*)attributes
{
    //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）
    //此时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  一般都是透明的上下文
    //scale:缩放比例 0:不缩放
    UIGraphicsBeginImageContextWithOptions(image.size,NO, 0);
    
    //1.绘制原生的图片
    [image drawAtPoint:CGPointZero];
    //2.给原生的图片添加文字
    NSString*str = title;
    
    [str drawAtPoint:CGPointMake(image.size.width-80, image.size.height-30) withAttributes:attributes];
    //3.从上下文获取生成的图片
    UIImage*imageWater = UIGraphicsGetImageFromCurrentImageContext();
    
    //4.关闭上下文
    UIGraphicsEndImageContext();
    
    return imageWater;
}