Quartz2D之图片裁切

图片裁剪

• 在开发中有的时候是需要裁剪图片的，比如说头像，裁剪成圆形，有的时候还有边框

UIImage *image = [UIImage imageNamed:@"icon"];
    // 图片的宽度和高度
    CGFloat imageWH = image.size.width;
    
    // 设置圆环的宽度
    CGFloat border = 3;
    
    // 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)];

    [[UIColor redColor] 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();