上一篇文章介紹了CoreGraphics,UIBezierPath就是路徑繪制的UIKit封裝，可以繪制矩形曲線等簡(jiǎn)單的圖形。所以，同樣的，使用UIBezierPath繪制圖形也是要在drawRect:方法中進(jìn)行。

大體步驟為：

1. 重寫view 的drawRect:方法
2. 創(chuàng)建UIBezierPath對(duì)象
3. moveToPoint:設(shè)置路徑起始點(diǎn)
4. 使用UIBezierPath的類方法繪制需要的路徑
5. 設(shè)置圖形屬性
6. 繪制圖形

使用UIBezierPath繪制簡(jiǎn)單的圖形

    //1.創(chuàng)建UIBezierPath
    UIBezierPath *path = [UIBezierPath bezierPath];
    //2.繪制路徑
    [path moveToPoint:CGPointMake(50, 300)];
    [path addLineToPoint:CGPointMake(50, 200)];
    [path addCurveToPoint:CGPointMake(350, 200) controlPoint1:CGPointMake(160, 50) controlPoint2:CGPointMake(240, 350)];
    [path addLineToPoint:CGPointMake(350, 300)];
    [path closePath];
    //3.設(shè)置圖形屬性
    [[UIColor redColor] setStroke];
    [[UIColor blueColor] setFill];
    path.lineWidth = 5;
    path.lineCapStyle = kCGLineCapRound;
    path.lineJoinStyle = kCGLineJoinRound;
    //4.繪制圖形
    [path fill];

UIBezierPathView1.png

一些常用屬性

//路徑寬度
@property(nonatomic) CGFloat lineWidth;

//路徑端點(diǎn)樣式
/*
    kCGLineCapButt    默認(rèn)，平的
    kCGLineCapRound   圓的
    kCGLineCapSquare  矩形
*/
@property(nonatomic) CGLineCap lineCapStyle;

//路徑拐點(diǎn)樣式
/*
    kCGLineJoinMiter    拐點(diǎn)形狀為尖的
    kCGLineJoinRound    拐點(diǎn)形狀為圓的
    kCGLineJoinBevel    拐點(diǎn)形狀為平的
*/
@property(nonatomic) CGLineJoin lineJoinStyle;

//最大斜接長(zhǎng)度 斜接長(zhǎng)度指的是在兩條線交匯處內(nèi)角和外角之間的距離，如果正常的斜接長(zhǎng)度大于miterLimit的值，則顯示類型類似kCGLineJoinBevel
@property(nonatomic) CGFloat miterLimit; // Used when lineJoinStyle is kCGLineJoinMiter

//確定路徑渲染的精確度，默認(rèn)值為0.6，值越小，渲染精度越高，計(jì)算時(shí)間也越長(zhǎng)。
@property(nonatomic) CGFloat flatness;

//渲染規(guī)則，設(shè)置為yes則路徑會(huì)使用奇偶規(guī)則填充，設(shè)置為no使用非零規(guī)則填充。
@property(nonatomic) BOOL usesEvenOddFillRule;

//獲取路徑的終點(diǎn)，如果當(dāng)前路徑為空, 那么該屬性的值將會(huì)是 CGPointZero
@property(nonatomic, readonly) CGPoint currentPoint;

一些常用方法

//創(chuàng)建一個(gè)路徑對(duì)象
+ (instancetype)bezierPath;

//創(chuàng)建一個(gè)矩形
+ (instancetype)bezierPathWithRect:(CGRect)rect;

//創(chuàng)建一個(gè)橢圓，內(nèi)切于矩形
+ (instancetype)bezierPathWithOvalInRect:(CGRect)rect;

//創(chuàng)建一個(gè)圓角矩形
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect cornerRadius:(CGFloat)cornerRadius; // rounds all corners with the same horizontal and vertical radius

//圓角位置可選的矩形
//rect:矩形位置及尺寸
//corners:圓弧所在角的位置，可多選
/*
    UIRectCornerTopLeft       左上角
    UIRectCornerTopRight      右上角
    UIRectCornerBottomLeft    左下角
    UIRectCornerBottomRight   右下角
    UIRectCornerAllCorners    所有角
*/
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect byRoundingCorners:(UIRectCorner)corners cornerRadii:(CGSize)cornerRadii;

//創(chuàng)建一個(gè)弧形
+ (instancetype)bezierPathWithArcCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise;

//利用CGPathRef創(chuàng)建路徑
+ (instancetype)bezierPathWithCGPath:(CGPathRef)CGPath;

//路徑移動(dòng)到某點(diǎn)
- (void)moveToPoint:(CGPoint)point;

//從當(dāng)前點(diǎn)劃一條到指定點(diǎn)的直線
- (void)addLineToPoint:(CGPoint)point;

//從當(dāng)前點(diǎn)劃一條到指定點(diǎn)的三次貝塞爾曲線
- (void)addCurveToPoint:(CGPoint)endPoint controlPoint1:(CGPoint)controlPoint1 controlPoint2:(CGPoint)controlPoint2;

//從當(dāng)前點(diǎn)劃一條到指定點(diǎn)的二次貝塞爾曲線
- (void)addQuadCurveToPoint:(CGPoint)endPoint controlPoint:(CGPoint)controlPoint;

//添加一段弧線
- (void)addArcWithCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise NS_AVAILABLE_IOS(4_0);

//關(guān)閉路徑
- (void)closePath;

//刪除路徑內(nèi)的所有點(diǎn)
- (void)removeAllPoints;

//拼接已經(jīng)存在的路徑
- (void)appendPath:(UIBezierPath *)bezierPath;

//返回一個(gè)當(dāng)前路徑翻轉(zhuǎn)后的路徑
- (UIBezierPath *)bezierPathByReversingPath NS_AVAILABLE_IOS(6_0);

//對(duì)路徑中的所有點(diǎn)進(jìn)行仿射變換
- (void)applyTransform:(CGAffineTransform)transform;

//設(shè)置虛線
//pattern  c語言數(shù)組，表示的是虛線的實(shí)線長(zhǎng)度和實(shí)現(xiàn)中間間隔距離
//count    pattern數(shù)組的個(gè)數(shù)
//phase    虛線從哪個(gè)位置開始繪制
- (void)setLineDash:(nullable const CGFloat *)pattern count:(NSInteger)count phase:(CGFloat)phase;

//重新獲取之前設(shè)置過的虛線樣式
- (void)getLineDash:(nullable CGFloat *)pattern count:(nullable NSInteger *)count phase:(nullable CGFloat *)phase;

//路徑中是否包含某個(gè)點(diǎn)，如果是封閉路徑，則返回封閉區(qū)域是否包含某個(gè)點(diǎn)
- (BOOL)containsPoint:(CGPoint)point;

//繪制路徑中間的填充
- (void)fill;

//繪制路徑
- (void)stroke;

//以指定模式填充路徑封閉的范圍
- (void)fillWithBlendMode:(CGBlendMode)blendMode alpha:(CGFloat)alpha;

//以指定模式繪制路徑
- (void)strokeWithBlendMode:(CGBlendMode)blendMode alpha:(CGFloat)alpha;

//剪切區(qū)域，路徑之外的區(qū)域?qū)⒉槐讳秩?- (void)addClip;

繪制矩形

    UIBezierPath *rectPath = [UIBezierPath bezierPathWithRect:CGRectMake(100, 100, 200, 100)];
    [[UIColor blueColor] set];
    [rectPath fill];

UIBezierPathView2.png

繪制橢圓

    UIBezierPath *ovalPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(100, 100, 200, 100)];
    [[UIColor blueColor] set];
    ovalPath.lineWidth = 2;
    [ovalPath stroke];

UIBezierPathView3.png

圓角矩形

    UIBezierPath *rectPath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 200, 100) cornerRadius:10];
    [[UIColor blueColor] set];
    rectPath.lineWidth = 2;
    [rectPath stroke];

UIBezierPathView4.png

自定義圓角矩形

    UIBezierPath *rectPath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(100, 100, 200, 100) byRoundingCorners:UIRectCornerTopLeft|UIRectCornerTopRight cornerRadii:CGSizeMake(10, 10)];
    [[UIColor blueColor] set];
    rectPath.lineWidth = 2;
    [rectPath stroke];

UIBezierPathView5.png

弧形

    UIBezierPath *arcPath = [UIBezierPath bezierPathWithArcCenter:CGPointMake(150, 150) radius:100 startAngle:-M_PI_2 endAngle:M_PI_4 clockwise:YES];
    [[UIColor blueColor] set];
    [arcPath fill];

UIBezierPathView6.png