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[操作系统]iOS关于CAShapeLayer与UIBezierPath的知识内容


使用CAShapeLayer与UIBezierPath可以实现不在view的drawRect方法中就画出一些想要的图形 。

1:UIBezierPath: UIBezierPath是在 UIKit 中的一个类,继承于NSObject,可以创建基于矢量的路径.此类是Core Graphics框架关于path的一个OC封装。使用此类可以定义常见的圆形、多边形等形状 。我们使用直线、弧(arc)来创建复杂的曲线形状。每一个直线段或者曲线段的结束的地方是下一个的开始的地方。每一个连接的直线或者曲线段的集合成为subpath。一个UIBezierPath对象定义一个完整的路径包括一个或者多个subpaths。

2:CAShapeLayer: CAShapeLayer顾名思义,继承于CALayer。 每个CAShapeLayer对象都代表着将要被渲染到屏幕上的一个任意的形状(shape)。具体的形状由其path(类型为CGPathRef)属性指定。 普通的CALayer是矩形,所以需要frame属性。CAShapeLayer初始化时也需要指定frame值,但 它本身没有形状,它的形状来源于其属性path 。CAShapeLayer有不同于CALayer的属性,它从CALayer继承而来的属性在绘制时是不起作用的。

实例1:画一个圆形

- (void)viewDidLoad {  [super viewDidLoad];     //创建出CAShapeLayer  self.shapeLayer = [CAShapeLayer layer];  self.shapeLayer.frame = CGRectMake(0, 0, 200, 200);//设置shapeLayer的尺寸和位置  self.shapeLayer.position = self.view.center;  self.shapeLayer.fillColor = [UIColor clearColor].CGColor;//填充颜色为ClearColor     //设置线条的宽度和颜色  self.shapeLayer.lineWidth = 1.0f;  self.shapeLayer.strokeColor = [UIColor redColor].CGColor;     //创建出圆形贝塞尔曲线  UIBezierPath *circlePath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 200, 200)];     //让贝塞尔曲线与CAShapeLayer产生联系  self.shapeLayer.path = circlePath.CGPath;     //添加并显示  [self.view.layer addSublayer:self.shapeLayer];}

现在我们要用到CAShapeLayer的两个参数,strokeEnd和strokeStart

Stroke:用笔画的意思

在这里就是起始笔和结束笔的位置

Stroke为1的话就是一整圈,0.5就是半圈,0.25就是1/4圈。以此类推

如果我们把起点设为0,终点设为0.75

//设置stroke起始点

self.shapeLayer.strokeStart = 0;

self.shapeLayer.strokeEnd = 0.75;

 

实例2:画两个圆,其中一个圆表示进度

//画两个圆形-(void)createBezierPath:(CGRect)mybound{  //外圆  _trackPath = [UIBezierPath bezierPathWithArcCenter:self.view.center radius:(mybound.size.width - 0.7)/ 2 startAngle:0 endAngle:M_PI * 2 clockwise:YES];;    _trackLayer = [CAShapeLayer new];  [self.view.layer addSublayer:_trackLayer];  _trackLayer.fillColor = nil;  _trackLayer.strokeColor=[UIColor grayColor].CGColor;  _trackLayer.path = _trackPath.CGPath;  _trackLayer.lineWidth=5;  _trackLayer.frame = mybound;    //内圆  _progressPath = [UIBezierPath bezierPathWithArcCenter:self.view.center radius:(mybound.size.width - 0.7)/ 2 startAngle:- M_PI_2 endAngle:(M_PI * 2) * 0.7 - M_PI_2 clockwise:YES];    _progressLayer = [CAShapeLayer new];  [self.view.layer addSublayer:_progressLayer];  _progressLayer.fillColor = nil;  _progressLayer.strokeColor=[UIColor redColor].CGColor;  _progressLayer.lineCap = kCALineCapRound;  _progressLayer.path = _progressPath.CGPath;  _progressLayer.lineWidth=5;  _progressLayer.frame = mybound;}

实例3:创建一个转动的圆

- (void)viewDidLoad {  [super viewDidLoad];    self.view.backgroundColor=[UIColor whiteColor];    [self circleBezierPath];  //用定时器模拟数值输入的情况  _timer = [NSTimer scheduledTimerWithTimeInterval:0.1                       target:self                      selector:@selector(circleAnimationTypeOne)                      userInfo:nil                       repeats:YES];}-(void)circleBezierPath{  //创建出CAShapeLayer  self.shapeLayer = [CAShapeLayer layer];  self.shapeLayer.frame = CGRectMake(0, 0, 150, 150);  self.shapeLayer.position = self.view.center;  self.shapeLayer.fillColor = [UIColor clearColor].CGColor;    //设置线条的宽度和颜色  self.shapeLayer.lineWidth = 2.0f;  self.shapeLayer.strokeColor = [UIColor redColor].CGColor;    //设置stroke起始点  self.shapeLayer.strokeStart = 0;  self.shapeLayer.strokeEnd = 0;    //创建出圆形贝塞尔曲线  UIBezierPath *circlePath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 150, 150)];    //让贝塞尔曲线与CAShapeLayer产生联系  self.shapeLayer.path = circlePath.CGPath;    //添加并显示  [self.view.layer addSublayer:self.shapeLayer];}- (void)circleAnimationTypeOne{  if (self.shapeLayer.strokeEnd > 1 && self.shapeLayer.strokeStart < 1) {    self.shapeLayer.strokeStart += 0.1;  }else if(self.shapeLayer.strokeStart == 0){    self.shapeLayer.strokeEnd += 0.1;  }    if (self.shapeLayer.strokeEnd == 0) {    self.shapeLayer.strokeStart = 0;  }    if (self.shapeLayer.strokeStart == self.shapeLayer.strokeEnd) {    self.shapeLayer.strokeEnd = 0;  }}- (void)circleAnimationTypeTwo{  CGFloat valueOne = arc4random() % 100 / 100.0f;  CGFloat valueTwo = arc4random() % 100 / 100.0f;    self.shapeLayer.strokeStart = valueOne < valueTwo ? valueOne : valueTwo;  self.shapeLayer.strokeEnd = valueTwo > valueOne ? valueTwo : valueOne;}

实例4:通过点画线组成一个五边线

//画一个五边形-(void)fiveAnimation{  UIBezierPath *aPath = [UIBezierPath bezierPath];  //开始点 从上左下右的点  [aPath moveToPoint:CGPointMake(100,100)];  //划线点  [aPath addLineToPoint:CGPointMake(60, 140)];  [aPath addLineToPoint:CGPointMake(60, 240)];  [aPath addLineToPoint:CGPointMake(160, 240)];  [aPath addLineToPoint:CGPointMake(160, 140)];  [aPath closePath];  //设置定点是个5*5的小圆形(自己加的)  UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(100-5/2.0, 0, 5, 5)];  [aPath appendPath:path];    CAShapeLayer *shapelayer = [CAShapeLayer layer];  //设置边框颜色  shapelayer.strokeColor = [[UIColor redColor]CGColor];  //设置填充颜色 如果只要边 可以把里面设置成[UIColor ClearColor]  shapelayer.fillColor = [[UIColor blueColor]CGColor];  //就是这句话在关联彼此(UIBezierPath和CAShapeLayer):  shapelayer.path = aPath.CGPath;  [self.view.layer addSublayer:shapelayer];}

实例5:画一条虚线

//画一条虚线-(void)createDottedLine{  CAShapeLayer *shapeLayer = [CAShapeLayer layer];  [shapeLayer setBounds:self.view.bounds];  [shapeLayer setPosition:self.view.center];  [shapeLayer setFillColor:[[UIColor clearColor] CGColor]];    // 设置虚线颜色为blackColor  [shapeLayer setStrokeColor:[[UIColor colorWithRed:223/255.0 green:223/255.0 blue:223/255.0 alpha:1.0f] CGColor]];    // 3.0f设置虚线的宽度  [shapeLayer setLineWidth:1.0f];  [shapeLayer setLineJoin:kCALineJoinRound];    // 3=线的宽度 1=每条线的间距  [shapeLayer setLineDashPattern:  [NSArray arrayWithObjects:[NSNumber numberWithInt:3],   [NSNumber numberWithInt:1],nil]];    // Setup the path  CGMutablePathRef path = CGPathCreateMutable();  CGPathMoveToPoint(path, NULL, 0, 89);  CGPathAddLineToPoint(path, NULL, 320,89);    [shapeLayer setPath:path];  CGPathRelease(path);    // 可以把self改成任何你想要的UIView, 下图演示就是放到UITableViewCell中的  [[self.view layer] addSublayer:shapeLayer];}

实例6:画一个弧线

//画一个弧线-(void)createCurvedLine{  UIBezierPath* aPath = [UIBezierPath bezierPath];  aPath.lineWidth = 5.0;  aPath.lineCapStyle = kCGLineCapRound; //线条拐角  aPath.lineJoinStyle = kCGLineCapRound; //终点处理  [aPath moveToPoint:CGPointMake(20, 100)];  [aPath addQuadCurveToPoint:CGPointMake(120, 100) controlPoint:CGPointMake(70, 0)];    self.CurvedLineLayer=[CAShapeLayer layer];  self.CurvedLineLayer.path=aPath.CGPath;  [self.view.layer addSublayer:self.CurvedLineLayer];}