用CAShapeLayer和UIBezierPath和CABaseAnimation制作动画折线图

 // 创建layer并设置属性

    CAShapeLayer *layer = [CAShapeLayer layer];

    layer.fillColor = [UIColor clearColor].CGColor;

    layer.lineWidth =  2.0f;

    layer.lineCap = kCALineCapRound;

    layer.lineJoin = kCALineJoinRound;

    layer.strokeColor = [UIColor redColor].CGColor;

    [self.view.layer addSublayer:layer];

    

    // 创建贝塞尔路径~

    UIBezierPath *path = [UIBezierPath bezierPath];

    [path moveToPoint:CGPointMake(10, 100)];

    [path addLineToPoint:CGPointMake(100, 200)];

    [path addLineToPoint:CGPointMake(200, 50)];

    [path addLineToPoint:CGPointMake(240, 150)];

    [path addLineToPoint:CGPointMake(300, 120)];

    

    // 关联layer和贝塞尔路径~

    layer.path = path.CGPath;

    

    // 创建Animation

    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];

    animation.fromValue = @(0.0);

    animation.toValue = @(1.0);

    layer.autoreverses = NO;

    animation.duration = 2.0;

    

    // 设置layer的animation

    [layer addAnimation:animation forKey:nil];

    

    // 第一种设置动画完成,不移除结果的方法

    //    animation.fillMode = kCAFillModeForwards;

    //    animation.removedOnCompletion = NO;

    

    // 第二种

    layer.strokeEnd = 1;