项目中需要设置这种button ,两个button一个左边是圆角一个右边是圆角。这个？裁张图省事的搞法。贝塞尔绘制这个好像难搞点哈。

1 常规圆角操作

    button.layer.cornerRadius = 圆角大小;

    button.layer.masksToBounds = YES;或

    button.clipsToBounds = YES;

这个会得到一个圆或者同时设置四个角的圆角大小。

2  设置任意一角为圆角 

typedef NS_OPTIONS(NSUInteger, UIRectCorner) {

    UIRectCornerTopLeft     = 1 << 0,

    UIRectCornerTopRight    = 1 << 1,

    UIRectCornerBottomLeft  = 1 << 2,

    UIRectCornerBottomRight = 1 << 3,

    UIRectCornerAllCorners  = ~0UL

};

注意下这个枚举 ，分别对应你要设置的哪个角！根据需求选

-( void)ctreateBtn{

 UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(50, 74, 200, 40)];

    [btn setBackgroundColor:[UIColor greenColor]];

    [btn setTitle:@"记录" forState:(UIControlStateNormal)];

  [btn setTitleColor:[UIColor blackColor] forState:(UIControlStateNormal)];

[btn addTarget:self action:@selector(btnClickAction:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btn]; //需要先添加

    

    //设置圆角

    CGFloat borderWidth = 1.0;

    CGFloat radius = 20.0f;

    

   UIBezierPath * path = [UIBezierPath bezierPathWithRoundedRect:btn.bounds byRoundingCorners:UIRectCornerTopLeft|UIRectCornerBottomLeft cornerRadii:CGSizeMake(radius, radius)];

    CAShapeLayer * mask  = [[CAShapeLayer alloc] init];

    mask.path = path.CGPath;

    btn.layer.mask = mask;

    

    CALayer * temp = [CALayer layer];

    [temp setBackgroundColor:[UIColor whiteColor].CGColor];

    temp.frame = CGRectMake(borderWidth, borderWidth, btn.bounds.size.width - borderWidth * 2, btn.bounds.size.height - borderWidth * 2);

    

    UIBezierPath * subPath = [UIBezierPath bezierPathWithRoundedRect:temp.bounds byRoundingCorners:UIRectCornerTopLeft|UIRectCornerBottomLeft cornerRadii:CGSizeMake(radius - borderWidth, radius - borderWidth)];

    CAShapeLayer * subMask  = [[CAShapeLayer alloc] initWithLayer:temp];

    subMask.path = subPath.CGPath;

    temp.mask = subMask;

    

    [btn.layer addSublayer:temp];

}

 //点击事件 及 切换边框线颜色   

-(void)btnClickAction:(UIButton*)btn{

    

    btn.selected = !btn.selected;

    if (btn.selected) {

           [btn setBackgroundColor:[UIColor greenColor]];

    } else {

           [btn setBackgroundColor:[UIColor redColor]];

    }

 

}