CAShapLayer的使用1

1.添加橙色圆环

- (CAShapeLayer *)shapeLayer {
    if (!_shapeLayer) {
        _shapeLayer = [CAShapeLayer layer];
        CGRect rect = {28,50,100,100};
        //bezierPathWithOvalInRect圆形路径 bezierPathWithRect 方形路径
        UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect: rect];
        _shapeLayer.strokeColor = [UIColor orangeColor].CGColor;
        _shapeLayer.lineWidth = 4;
        _shapeLayer.fillColor = [UIColor clearColor].CGColor;
        _shapeLayer.lineCap = kCALineCapRound;
        _shapeLayer.path = path.CGPath;
    }
    return _shapeLayer;
}

2.添加进度条

- (CAShapeLayer *)progressLayer {
    if (!_progressLayer) {
        _progressLayer = [CAShapeLayer layer];
        _progressLayer.frame = self.shapeLayer.bounds;
        _progressLayer.fillColor = [UIColor clearColor].CGColor;
        _progressLayer.strokeColor = [UIColor whiteColor].CGColor;
        _progressLayer.lineWidth = 4;
        _progressLayer.lineCap = kCALineCapRound;
        CGRect rect = {28,50,100,100};
        UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect: rect];
        _progressLayer.path = path.CGPath;
    }
    return _progressLayer;
}

3.添加渐变颜色

[self.view.layer addSublayer: self.shapeLayer];
    [self.view.layer addSublayer: self.progressLayer];
    
    
    CAGradientLayer * gradientLayer1 = [CAGradientLayer layer];
    gradientLayer1.frame = self.view.bounds;
    
    CGColorRef red = [UIColor redColor].CGColor;
    CGColorRef purple = [UIColor purpleColor].CGColor;
    CGColorRef yellow = [UIColor yellowColor].CGColor;
    CGColorRef orange = [UIColor orangeColor].CGColor;
    
    gradientLayer1.colors = @[(__bridge id)red,(__bridge id)purple,(__bridge id)yellow,(__bridge id)orange];
    gradientLayer1.locations = @[@0.3, @0.6,@0.8,@1.0];
    gradientLayer1.startPoint = CGPointMake(0.5, 1);
    gradientLayer1.endPoint = CGPointMake(0.5, 0);
    
    //一定要设置gradientLayer.mask = self.progressLayer;这样才能显示中间的内容，如果不设置mask，那么就只有渐变图层了
    gradientLayer1.mask = self.progressLayer;
    [self.view.layer addSublayer: gradientLayer1]; //添加渐变

4.执行动画

- (IBAction)change:(UISlider * )sender {
    CGFloat cV = sender.value * 100;
    [self updateProgressWithNumber: cV];
    
}


- (void)updateProgressWithNumber:(NSUInteger)number {
    [CATransaction begin];
    [CATransaction setAnimationTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]];
    [CATransaction setAnimationDuration:0.5];
    self.progressLayer.strokeEnd =  number / 100.0;
    NSLog(@"%@",[NSString stringWithFormat:@"%@%%", @(number)]);
    [CATransaction commit];
}