• 这里要实现的是带有两个圆角的自定义的UIlabel

  
  
  两个圆角的UIlabel.png
• 主要思路是利用贝塞尔曲线绘制masklayer的轨迹。
  下面直接看代码：

#import "CustomizeLabel.h"

@interface CustomizeLabel()

@property (nonatomic, strong)CAShapeLayer *maskLayer;
@property (nonatomic, strong)UIBezierPath *borderPath;

@end

@implementation CustomizeLabel

- (instancetype)initWithFrame:(CGRect)frame{
    
    self = [super initWithFrame:frame];
    if(self){
        
        _maskLayer = [CAShapeLayer layer];
        [self.layer setMask:_maskLayer];
        
        self.borderPath = [UIBezierPath bezierPath];
    }
    return self;
}

- (void)layoutSubviews{
    
    [super layoutSubviews];
    
    // 遮罩层frame
    self.maskLayer.frame = self.bounds;
    
    // 设置path起点
    [self.borderPath moveToPoint:CGPointMake(0, 10)];
    // 左上角的圆角
    [self.borderPath addQuadCurveToPoint:CGPointMake(10, 0) controlPoint:CGPointMake(0, 0)];
    //直线，到右上角
    [self.borderPath addLineToPoint:CGPointMake(self.bounds.size.width, 0)];
    //直线，到右下角
    [self.borderPath addLineToPoint:CGPointMake(self.bounds.size.width, self.bounds.size.height-10)];
    //右下角的圆角
    [self.borderPath addQuadCurveToPoint:CGPointMake(self.bounds.size.width-10, self.bounds.size.height) controlPoint:CGPointMake(self.bounds.size.width, self.bounds.size.height)];
    //底部的小三角形
    [self.borderPath addLineToPoint:CGPointMake(self.bounds.size.width/2.0 +5, self.bounds.size.height)];
    [self.borderPath addLineToPoint:CGPointMake(self.bounds.size.width/2.0, self.bounds.size.height - 5)];
    [self.borderPath addLineToPoint:CGPointMake(self.bounds.size.width/2.0 -5, self.bounds.size.height)];
    //直线到左下角
    [self.borderPath addLineToPoint:CGPointMake(0, self.bounds.size.height)];
    //直线，回到起点
    [self.borderPath addLineToPoint:CGPointMake(0, 10)];
        
    // 将这个path赋值给maskLayer的path
    self.maskLayer.path = self.borderPath.CGPath;
}

@end

• 使用：

    CustomizeLabel *label = [[CustomizeLabel alloc] initWithFrame:CGRectMake(100, 100, 200, 100)];
    label.text = @"现在我们来测试一下这个自定义的按钮";
    label.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:label];