UIBezierPath接口文档

//
//  UIBezierPath.h
//  UIKit
//
//  Copyright (c) 2009-2015 Apple Inc. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <CoreGraphics/CoreGraphics.h>
#import <UIKit/UIKitDefines.h>

NS_ASSUME_NONNULL_BEGIN

typedef NS_OPTIONS(NSUInteger, UIRectCorner) {
    UIRectCornerTopLeft     = 1 << 0,      // 上左圆角
    UIRectCornerTopRight    = 1 << 1,     // 上右圆角
    UIRectCornerBottomLeft  = 1 << 2,     // 下左圆角
    UIRectCornerBottomRight = 1 << 3,    // 下右圆角
    UIRectCornerAllCorners  = ~0UL          //  四个角都是圆角
};

NS_CLASS_AVAILABLE_IOS(3_2) @interface UIBezierPath : NSObject<NSCopying, NSCoding>

// 创建一个贝塞尔曲线
+ (instancetype)bezierPath;

// 创建一个方形
+ (instancetype)bezierPathWithRect:(CGRect)rect;

// 创建一个椭圆
+ (instancetype)bezierPathWithOvalInRect:(CGRect)rect;

// 创建一个圆角方形
// cornerRadius：圆角半径
// rounds all corners with the same horizontal and vertical radius
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect cornerRadius:(CGFloat)cornerRadius; 

// 创建一个圆角方形
// cornerRadii：圆角size
// corners:    圆角位置
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect byRoundingCorners:(UIRectCorner)corners cornerRadii:(CGSize)cornerRadii;

// 创建一个弧线
// center:弧线中心点
// startAngle:弧线开始角度
// endAngle:结束角度
// clockwise:是否是顺时针方向 YES：顺时针
+ (instancetype)bezierPathWithArcCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise;

// 通过已经有的CGPathRef路径，创建贝塞尔曲线
+ (instancetype)bezierPathWithCGPath:(CGPathRef)CGPath;

// 初始化方法
- (instancetype)init NS_DESIGNATED_INITIALIZER;

// 
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_DESIGNATED_INITIALIZER;

// Returns an immutable CGPathRef which is only valid until the UIBezierPath is further mutated.
// Setting the path will create an immutable copy of the provided CGPathRef, so any further mutations on a provided CGMutablePathRef will be ignored.

// 贝塞尔曲线的路径属性
@property(nonatomic) CGPathRef CGPath;
- (CGPathRef)CGPath NS_RETURNS_INNER_POINTER CF_RETURNS_NOT_RETAINED;

// Path construction

// 移动到某个点
- (void)moveToPoint:(CGPoint)point;

// 添加线段到某个点
- (void)addLineToPoint:(CGPoint)point;

// 添加曲线到某个点
// endPoint:曲线末尾的点
// controlPoint1:贝塞尔曲线控制点一
// controlPoint2:贝塞尔曲线控制点二
- (void)addCurveToPoint:(CGPoint)endPoint controlPoint1:(CGPoint)controlPoint1 controlPoint2:(CGPoint)controlPoint2;

// 添加曲线到某个点
// endPoint:曲线末尾的点
// controlPoint:贝塞尔曲线控制点
- (void)addQuadCurveToPoint:(CGPoint)endPoint controlPoint:(CGPoint)controlPoint;

// 添加弧线
// center:弧线中心点
// startAngle:开始角度
// endAngle:末尾角度
// clockwise:是否是顺时针
- (void)addArcWithCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise NS_AVAILABLE_IOS(4_0);

// 关闭路径
- (void)closePath;

// 删除所有的点儿
- (void)removeAllPoints;

// 追加贝塞尔曲线
- (void)appendPath:(UIBezierPath *)bezierPath;

// 翻转贝塞尔曲线
// Modified paths
- (UIBezierPath *)bezierPathByReversingPath NS_AVAILABLE_IOS(6_0);

// 使用矩阵变换
// Transforming paths
- (void)applyTransform:(CGAffineTransform)transform;

// Path info(路径信息)
@property(readonly,getter=isEmpty) BOOL empty;  // 是否是空路径
@property(nonatomic,readonly) CGRect bounds;    // 路径的bounds
@property(nonatomic,readonly) CGPoint currentPoint;  // 路径当前的点
- (BOOL)containsPoint:(CGPoint)point;                          // 路径是否包含某个点

// Drawing properties (绘制属性)
@property(nonatomic) CGFloat lineWidth;                //  线宽
@property(nonatomic) CGLineCap lineCapStyle;       //  线头 & 线尾的样式(圆、)
@property(nonatomic) CGLineJoin lineJoinStyle;       //  两条线交接地方的样式(圆、)
@property(nonatomic) CGFloat miterLimit; // Used when lineJoinStyle is kCGLineJoinMiter(该属性起作用，当 lineJoinStyle = kCGLineJoinMiter的时候)
@property(nonatomic) CGFloat flatness;                // 待定
@property(nonatomic) BOOL usesEvenOddFillRule; // Default is NO. When YES, the even-odd fill rule is used for drawing, clipping, and hit testing.

// 设置虚线
- (void)setLineDash:(nullable const CGFloat *)pattern count:(NSInteger)count phase:(CGFloat)phase;

// 
- (void)getLineDash:(nullable CGFloat *)pattern count:(nullable NSInteger *)count phase:(nullable CGFloat *)phase;

// Path operations on the current graphics context

// 填充
- (void)fill;

// 描边
- (void)stroke;

// These methods do not affect the blend mode or alpha of the current graphics context
- (void)fillWithBlendMode:(CGBlendMode)blendMode alpha:(CGFloat)alpha;
- (void)strokeWithBlendMode:(CGBlendMode)blendMode alpha:(CGFloat)alpha;

// 添加裁剪
- (void)addClip;

@end

NS_ASSUME_NONNULL_END