注：本篇文章都要写在UIView的-drawRect:方法里。

1. 直线

- (void)drawRect:(CGRect)rect
{
    [[UIColor redColor] set];
    
    {// 1. 直线
        UIBezierPath *path = [[UIBezierPath alloc] init]; //初始化也可以用 [UIBezierPath bezierPath];
        path.lineWidth = 3.f;
        path.lineCapStyle = kCGLineCapRound; //端点样式（圆形）
        path.lineJoinStyle = kCGLineJoinRound; //连接类型
        path.miterLimit = 10.f;
        path.flatness = 10.f; //绘线的精细程度，默认为0.6，数值越大，需要处理的时间越长
        path.usesEvenOddFillRule = YES;

        // 设置起始点
        [path moveToPoint:CGPointMake(30, 30)];
        
        // 添加子路径
        [path addLineToPoint:CGPointMake(100, 20)];//添加一条子路径
        [path addLineToPoint:CGPointMake(200, 50)];//添加一条子路径
        [path closePath]; //当构建子路径数>=2条时,可以调用`closePath`方法来闭合路径.
        
        // 根据坐标点连线
        [path stroke]; //各个点连线
}

2. 矩形、圆角矩形

// 2.矩形，可以用3个 addLineToPoint: 方法，也可以直接用下面方法：
UIBezierPath *path = [UIBezierPath bezierPathWithRect:CGRectMake(20, 70, 50, 50)];
[path fill]; //设置填充
[path stroke]; //各个点连线

// 3.圆角矩形
UIBezierPath *path1 = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(120, 70, 50, 50) 
                                                 cornerRadius:10];
[path1 stroke];
        
UIBezierPath *path2 = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(220, 70, 50, 50)
                                            byRoundingCorners:UIRectCornerTopLeft|UIRectCornerBottomRight
                                                  cornerRadii:CGSizeMake(10, 10)];
[path2 stroke];

3. 椭圆

UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(20, 140, 100, 50)];
[path stroke];

4. 圆弧

UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(20, 200)
                                                    radius:50
                                                startAngle:0
                                                  endAngle:M_PI/2
                                                 clockwise:YES];
[path fill];
[path stroke];

5. 扇形

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(100, 260)];
[path addArcWithCenter:CGPointMake(200, 260) radius:50 startAngle:0 endAngle:M_PI/2 clockwise:YES];
[path closePath]; //形成闭环
[path stroke];

6. 虚线

UIBezierPath *path = [UIBezierPath bezierPath];
//椭圆虚线
//UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(100, 100, 100, 200)]; 
//圆虚线
//UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 100, 100) cornerRadius:40]; 
CGFloat dash[] = {3.0, 3.0};
[path setLineDash:dash    //各段虚线长度
            count:2       //数组数量
            phase:0.0];   //起始位置
[path moveToPoint:CGPointMake(20, 320)];
[path addLineToPoint:CGPointMake(200, 320)];
[path stroke];

7. 二次贝塞尔曲线

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0, 360)];
[path addQuadCurveToPoint:CGPointMake(200, 360)    //终点
             controlPoint:CGPointMake(100, 320)];  //控制点
[path stroke];

8. 三次贝塞尔曲线

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0, 400)];
[path addCurveToPoint:CGPointMake(300, 400)    //终点
        controlPoint1:CGPointMake(100, 350)    //控制点
        controlPoint2:CGPointMake(200, 450)];  //控制点
[path stroke];

9. 用CAShapeLayer设置边框颜色

UIBezierPath *pathA = [UIBezierPath bezierPathWithRect:CGRectMake(100, 480, 100, 100)];

CAShapeLayer *layerA = [[CAShapeLayer alloc] init];
layerA.lineWidth = 5.0f;
layerA.strokeColor = [UIColor orangeColor].CGColor; //线色
layerA.fillColor = [UIColor greenColor].CGColor; //背景色
[self.layer addSublayer:layerA];

layerA.path = pathA.CGPath;

10. 用CAShapeLayer加阴影

CGRect frame = CGRectMake(260, 260, 50, 50);
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:frame];

CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.fillColor = [UIColor greenColor].CGColor;
shapeLayer.shadowOffset = CGSizeMake(5, 5);
shapeLayer.shadowColor = [UIColor blackColor].CGColor;
shapeLayer.shadowOpacity = 0.5;
[self.layer addSublayer:shapeLayer];

shapeLayer.path = path.CGPath;

下载Demo：https://gitee.com/lazyoung/uibezier-path_-demo

参考文章：https://www.jianshu.com/p/b561e208f51f