- (void)viewDidLoad {[super viewDidLoad]; //加载图片UIImage *image = [UIImage imageNamed:@"菲哥"]; //获取图片尺寸CGSize size = image.size; //开启位图上下文UIGraphicsBeginImageContextWithOptions(size, NO, 0); //创建圆形路径UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, image.size.width, image.size.height)]; //设置为裁剪区域[path addClip]; //绘制图片[image drawAtPoint:CGPointZero]; //获取裁剪后的图片_imageView.image = UIGraphicsGetImageFromCurrentImageContext(); //关闭上下文UIGraphicsEndImageContext(); }再来一张菲哥的头像
如果想要在圆形头像外加一个边框,思路是先绘制一个大圆,然后在这个圆尺寸范围内绘制一个图片大小的圆。
- (void)viewDidLoad {[super viewDidLoad]; //加载图片UIImage *image = [UIImage imageNamed:@"大菲哥"]; //设置边框宽度CGFloat border = 3;CGFloat imageWH = image.size.width; //计算外圆的尺寸CGFloat ovalWH = imageWH + 2 * border; //开启上下文UIGraphicsBeginImageContextWithOptions(image.size, NO, 0); //画一个大的圆形UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, ovalWH, ovalWH)]; [[UIColor orangeColor]set]; [path fill]; //设置裁剪区域UIBezierPath *path1 = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(border, border, imageWH, imageWH)];[path1 addClip]; //绘制图片[image drawAtPoint:CGPointMake(border, border)]; //从上下文中获取图片_imageView.image = UIGraphicsGetImageFromCurrentImageContext(); //关闭上下文UIGraphicsEndImageContext(); }效果如图:
屏幕截图代码:
原理就是把屏幕上控件的layer渲染到上下文中
- (void)viewDidLoad {[super viewDidLoad]; //开启上下文UIGraphicsBeginImageContextWithOptions(self.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[self.view.layer renderInContext:ctx]; //获取上下文中的图片UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); //关闭上下文UIGraphicsEndImageContext(); //保存图片到相册UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil); }以上就是本文的全部内容,希望对大家的学习有所帮助。