<h1 align = "center">iOS给图片设置圆角</h1>
通过设置layer的属性(最常用的方法)
最快速，但是影响性能，代码如下
UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
imageView.backgroundColor = [UIColor redColor];
//设置layer层的两个属性
//设置圆角
imageView.layer.cornerRadius = imageView.frame.size.width / 2;
//将多余的部分切掉,这句话一定要有，不然有时候显示不出来
imageView.layer.masksToBounds = YES;
[self.view addSubview:imageView];
通过CAShapeLayer和贝塞尔曲线UIBezierPath画圆角图片
UIImageView *imageShape = [[UIImageView alloc]initWithFrame:CGRectMake(100, 360, 100, 100)];
imageShape.image = [UIImage imageNamed:@"01.jpg"];
imageShape.backgroundColor = [UIColor purpleColor];
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:imageShape.bounds
byRoundingCorners:UIRectCornerAllCorners
cornerRadii:imageShape.bounds.size];
CAShapeLayer *maskLayer = [[CAShapeLayer alloc]init];
maskLayer.frame = imageShape.bounds;
maskLayer.path = maskPath.CGPath;
imageShape.layer.mask = maskLayer;
[self.view addSubview:imageShape];
用UIBezier曲线和Core Graphics(推荐)
UIImageView * imageBezier = [[UIImageView alloc]initWithFrame:CGRectMake(100, 220, 100, 100)];
imageBezier.image = [UIImage imageNamed:@"01.jpg"];
imageBezier.backgroundColor = [UIColor blueColor];
//开始对imageView进行画图
UIGraphicsBeginImageContextWithOptions(imageBezier.bounds.size, NO, 1.0);
//使用贝塞尔曲线画出一个圆形图
UIBezierPath * path = [UIBezierPath bezierPathWithRoundedRect:imageBezier.bounds cornerRadius:imageBezier.frame.size.width] ;
[path addClip];
[imageBezier drawRect:imageBezier.bounds];
imageBezier.image = UIGraphicsGetImageFromCurrentImageContext();
//结束画图
UIGraphicsEndImageContext();
[self.view addSubview:imageBezier];
