IOS第17天(2,Quartz2D图片剪裁变圆行图，和截屏图片）

#import "HMViewController.h"

#import "UIImage+Tool.h"

@interface HMViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@end

@implementation HMViewController

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

//    _imageView.image = [UIImage imageWithName:@"阿狸头像" border:10 borderColor:[UIColor redColor]];

[self clipCircle];

}

- (void)clipCircle
{
// 圆环的宽度
CGFloat borderW = 5;

// 加载旧的图片
UIImage *oldImage =  [UIImage imageNamed:@"阿狸头像"];

// 新的图片尺寸
CGFloat imageW = oldImage.size.width + 2 * borderW;
CGFloat imageH = oldImage.size.height + 2 * borderW;

// 设置新的图片尺寸
CGFloat circirW = imageW > imageH ? imageH : imageW;

// 开启上下文
UIGraphicsBeginImageContextWithOptions(CGSizeMake(circirW, circirW), NO, 0.0);

// 画大圆
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, circirW, circirW)];

// 获取当前上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();

// 添加到上下文
CGContextAddPath(ctx, path.CGPath);

[[UIColor whiteColor] set];      //边框颜色

// 渲染
CGContextFillPath(ctx);

CGRect clipR = CGRectMake(borderW, borderW, oldImage.size.width, oldImage.size.height);

// 画圆：正切于旧图片的圆
UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:clipR];

// 设置裁剪区域
[clipPath addClip];

// 画图片
[oldImage drawAtPoint:CGPointMake(borderW, borderW)];

// 获取新的图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

// 关闭上下文
UIGraphicsEndImageContext();

_imageView.image = newImage;
}

- (void)clip
{
// 1.加载旧的图片
UIImage *oldImage = [UIImage imageNamed:@"阿狸头像"];

// 2.开启上下文
UIGraphicsBeginImageContextWithOptions(oldImage.size, NO, 0.0);

// 3.画圆：正切于上下文
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, oldImage.size.width, oldImage.size.height)];

// 4.设为裁剪区域
[path addClip];

// 5.画图片
[oldImage drawAtPoint:CGPointZero];

// 6.生成一个新的图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

// 7.关闭上下文
UIGraphicsEndImageContext();
}
@end

#import "UIImage+Tool.h"

@implementation UIImage (Tool)

+ (instancetype)imageWithCaptureView:(UIView *)view
{
// 开启上下文
UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 0.0);

// 获取上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();

// 渲染控制器view的图层到上下文
// 图层只能用渲染不能用draw
[view.layer renderInContext:ctx];

// 获取截屏图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

// 关闭上下文
UIGraphicsEndImageContext();

return newImage;
}

+ (instancetype)imageWithName:(NSString *)name border:(CGFloat)border borderColor:(UIColor *)color
{
// 圆环的宽度
CGFloat borderW = border;

// 加载旧的图片
UIImage *oldImage =  [UIImage imageNamed:name];

// 新的图片尺寸
CGFloat imageW = oldImage.size.width + 2 * borderW;
CGFloat imageH = oldImage.size.height + 2 * borderW;

// 设置新的图片尺寸
CGFloat circirW = imageW > imageH ? imageH : imageW;

// 开启上下文
UIGraphicsBeginImageContextWithOptions(CGSizeMake(circirW, circirW), NO, 0.0);

// 画大圆
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, circirW, circirW)];

// 获取当前上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();

// 添加到上下文
CGContextAddPath(ctx, path.CGPath);

// 设置颜色
[color set];

// 渲染
CGContextFillPath(ctx);

CGRect clipR = CGRectMake(borderW, borderW, oldImage.size.width, oldImage.size.height);

// 画圆：正切于旧图片的圆
UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:clipR];

// 设置裁剪区域
[clipPath addClip];

// 画图片
[oldImage drawAtPoint:CGPointMake(borderW, borderW)];

// 获取新的图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

// 关闭上下文
UIGraphicsEndImageContext();

return newImage;
}

@end