创建任意圆角个数

    CGRect rect =CGRectMake(50,50,100,100);

    CGSize radii =CGSizeMake(20,20);

    UIRectCorner corners =UIRectCornerTopRight |UIRectCornerBottomRight |UIRectCornerBottomLeft;

    UIBezierPath *path = [UIBezierPathbezierPathWithRoundedRect:rectbyRoundingCorners:corners cornerRadii:radii];

    

    CAShapeLayer *layer = [CAShapeLayerlayer];

    layer.strokeColor = [UIColorredColor].CGColor;

    layer.lineWidth =5;

    layer.lineJoin =kCALineJoinRound;

    layer.lineCap =kCALineCapRound;

    layer.fillColor = [UIColorblueColor].CGColor;

    layer.path = path.CGPath;

    [self.view.layeraddSublayer:layer];