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]; }
另外.....
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世界和平.........