UIBezierPath介绍

前言

UIBezierPath是UIKit中的一个关于图形绘制的类，是通过Quartz 2D也就是CG（Core Graphics）CGPathRef的封装得到的，从高级特性支持来看不及CG。

UIBezierPath类可以绘制矩形、圆形、直线、曲线以及它们的组合图形。

UIBezierPath对象

对象创建方法

// 创建基本路径
+ (instancetype)bezierPath;
// 创建矩形路径
+ (instancetype)bezierPathWithRect:(CGRect)rect;
// 创建椭圆路径
+ (instancetype)bezierPathWithOvalInRect:(CGRect)rect;
// 创建圆角矩形
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect cornerRadius:(CGFloat)cornerRadius; // rounds all corners with the same horizontal and vertical radius
// 创建指定位置圆角的矩形路径
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect byRoundingCorners:(UIRectCorner)corners cornerRadii:(CGSize)cornerRadii;
// 创建弧线路径
+ (instancetype)bezierPathWithArcCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise;
// 通过CGPath创建
+ (instancetype)bezierPathWithCGPath:(CGPathRef)CGPath;

相关属性和方法

属性

// 与之对应的CGPath
@property(nonatomic) CGPathRef CGPath;
- (CGPathRef)CGPath NS_RETURNS_INNER_POINTER CF_RETURNS_NOT_RETAINED;

// 是否为空
@property(readonly,getter=isEmpty) BOOL empty;
// 整个路径相对于原点的位置及宽高
@property(nonatomic,readonly) CGRect bounds;
// 当前画笔位置
@property(nonatomic,readonly) CGPoint currentPoint;

// 线宽
@property(nonatomic) CGFloat lineWidth;// 终点类型
@property(nonatomic) CGLineCap lineCapStyle;
typedef CF_ENUM(int32_t, CGLineCap) {kCGLineCapButt,kCGLineCapRound,kCGLineCapSquare
};// 交叉点的类型
@property(nonatomic) CGLineJoin lineJoinStyle;
typedef CF_ENUM(int32_t, CGLineJoin) {kCGLineJoinMiter,kCGLineJoinRound,kCGLineJoinBevel
};// 两条线交汇处内角和外角之间的最大距离,需要交叉点类型为kCGLineJoinMiter是生效，最大限制为10
@property(nonatomic) CGFloat miterLimit;
// 个人理解为绘线的精细程度，默认为0.6，数值越大，需要处理的时间越长
@property(nonatomic) CGFloat flatness;
// 决定使用even-odd或者non-zero规则
@property(nonatomic) BOOL usesEvenOddFillRule;

方法

// 反方向绘制path

- (UIBezierPath *)bezierPathByReversingPath;

// 设置画笔起始点

- (void)moveToPoint:(CGPoint)point;

// 从当前点到指定点绘制直线

- (void)addLineToPoint:(CGPoint)point;

// 添加弧线

- (void)addArcWithCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise NS_AVAILABLE_IOS(4_0);
// center弧线圆心坐标 radius弧线半径 startAngle弧线起始角度 endAngle弧线结束角度 clockwise是否顺时针绘制

// 添加贝塞尔曲线

- (void)addQuadCurveToPoint:(CGPoint)endPoint controlPoint:(CGPoint)controlPoint;
// endPoint终点 controlPoint控制点
- (void)addCurveToPoint:(CGPoint)endPoint controlPoint1:(CGPoint)controlPoint1 controlPoint2:(CGPoint)controlPoint2;
// endPoint终点 controlPoint1、controlPoint2控制点

// 移除所有的点，删除所有的subPath

- (void)removeAllPoints;

// 将bezierPath添加到当前path

- (void)appendPath:(UIBezierPath *)bezierPath;

// 填充

- (void)fill;

// 路径绘制

- (void)stroke;

// 在这以后的图形绘制超出当前路径范围则不可见

- (void)addClip;

直线

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];UIBezierPath* path = [UIBezierPath bezierPath];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;// 起点[path moveToPoint:CGPointMake(20, 100)];// 绘制线条[path addLineToPoint:CGPointMake(200, 20)];[path stroke];
}

矩形

直角矩形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];// 创建矩形路径对象UIBezierPath * path = [UIBezierPath bezierPathWithRect:CGRectMake(50, 50, 150, 100)];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path stroke];
}

圆角矩形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];// 创建圆角矩形路径对象UIBezierPath* path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(20, 20, 150, 100) cornerRadius:30]; // 圆角半径为30path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path stroke];
}

指定位置圆角矩形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];UIBezierPath* path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(20, 20, 150, 100) byRoundingCorners:UIRectCornerTopLeft cornerRadii:CGSizeMake(30, 30)];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path stroke];
}

corners：圆角位置 cornerRadii：圆角大小

typedef NS_OPTIONS(NSUInteger, UIRectCorner) {UIRectCornerTopLeft     = 1 << 0,UIRectCornerTopRight    = 1 << 1,UIRectCornerBottomLeft  = 1 << 2,UIRectCornerBottomRight = 1 << 3,UIRectCornerAllCorners  = ~0UL
};

圆形和椭圆形

圆形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];// 创建圆形路径对象UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(50, 50, 100, 100)];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path stroke];
}

椭圆形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];// 创建椭圆形路径对象UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(50, 50, 100, 100)];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path stroke];
}

曲线

弧线

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];// 创建弧线路径对象UIBezierPath* path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(100, 100)radius:70startAngle:3.1415926endAngle:3.1415926 *3/2clockwise:YES];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path stroke];
}

center：弧线圆心坐标
radius：弧线半径
startAngle：弧线起始角度
endAngle：弧线结束角度
clockwise：是否顺时针绘制

默认坐标系统中的角度值

贝塞尔曲线1

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];UIBezierPath* path = [UIBezierPath bezierPath];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path moveToPoint:CGPointMake(20, 100)];// 给定终点和控制点绘制贝塞尔曲线[path addQuadCurveToPoint:CGPointMake(150, 100) controlPoint:CGPointMake(20, 0)];[path stroke];
}

贝塞尔曲线2

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];UIBezierPath* path = [UIBezierPath bezierPath];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;[path moveToPoint:CGPointMake(20, 100)];// 给定终点和两个控制点绘制贝塞尔曲线[path addCurveToPoint:CGPointMake(220, 100) controlPoint1:CGPointMake(120, 20) controlPoint2:CGPointMake(120, 180)];[path stroke];
}

扇形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set]; // 画笔颜色设置UIBezierPath * path = [UIBezierPath bezierPath]; // 创建路径[path moveToPoint:CGPointMake(100, 100)]; // 设置起始点[path addArcWithCenter:CGPointMake(100, 100) radius:75 startAngle:0 endAngle:3.14159/2 clockwise:NO]; // 绘制一个圆弧path.lineWidth     = 5.0;path.lineCapStyle  = kCGLineCapRound; //线条拐角path.lineJoinStyle = kCGLineCapRound; //终点处理[path closePath]; // 封闭未形成闭环的路径[path stroke]; // 绘制
}

多边形

- (void)drawRect:(CGRect)rect{[[UIColor redColor] set];UIBezierPath* path = [UIBezierPath bezierPath];path.lineWidth     = 5.f;path.lineCapStyle  = kCGLineCapRound;path.lineJoinStyle = kCGLineCapRound;// 起点[path moveToPoint:CGPointMake(100, 50)];// 添加直线[path addLineToPoint:CGPointMake(150, 50)];[path addLineToPoint:CGPointMake(200, 100)];[path addLineToPoint:CGPointMake(200, 150)];[path addLineToPoint:CGPointMake(150, 200)];[path addLineToPoint:CGPointMake(100, 200)];[path addLineToPoint:CGPointMake(50, 150)];[path addLineToPoint:CGPointMake(50, 100)];[path closePath];//根据坐标点连线[path stroke];[path fill];
}

参考：
http://www.jianshu.com/p/60aad4957923
http://www.jianshu.com/p/bbb2cc485a45