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金融类项目时经常需要绘制各类曲线,这里列出了一些常见的曲线展示动画,思路可供参考

1.曲线出现的时候向y轴两边拉伸

不废话了,直接抛demo代码

- (void)viewDidLoad {
    [super viewDidLoad];
    //中心轴线
    UIBezierPath *Nopath = [UIBezierPath bezierPath];
    [Nopath moveToPoint:CGPointMake(0, 40)];
    //封闭图形
    UIBezierPath *fillpath = [UIBezierPath bezierPath];
    [fillpath moveToPoint:CGPointMake(0, 0)];

    for (int i = 0; i < 20; i ++) {
        if (i<5) {
            
            [fillpath addLineToPoint:CGPointMake(20*i, 20*i)];
            [Nopath addLineToPoint:CGPointMake(15*i, 40)];
            
        }else if(i <10)
        {
            [fillpath addLineToPoint:CGPointMake(15*i, 10*i)];
            [Nopath addLineToPoint:CGPointMake(15*i, 40)];
            
        }else{
            [fillpath addLineToPoint:CGPointMake(18*i, 6*i)];
            [Nopath addLineToPoint:CGPointMake(18*i, 40)];
            
        }
        
        if (i ==19) {
            //这几个点很关键...
            [fillpath addLineToPoint:CGPointMake(18*i, 6*i)];
            [fillpath addLineToPoint:CGPointMake(18*i, 40)];
            [Nopath addLineToPoint:CGPointMake(18*i, 40)];
            [Nopath addLineToPoint:CGPointMake(18*i, 40)];
            
        }
    }
    //这几个点也很关键...
    [Nopath addLineToPoint:CGPointMake(0, 40)];
    [Nopath addLineToPoint:CGPointMake(0, 40)];
    
    [fillpath addLineToPoint:CGPointMake(0, 40)];
    [fillpath addLineToPoint:CGPointMake(0, 0)];
    
    //layer
    CAShapeLayer *layer = [CAShapeLayer layer];
    layer.frame = CGRectMake(20, 20, 200, 200);
    layer.bounds = CGRectMake(0, 0, 200, 200);
    layer.path = fillpath.CGPath;
    layer.fillColor = [UIColor greenColor].CGColor;
    layer.lineJoin = kCALineCapRound;
    [self.view.layer addSublayer:layer];

    //动画
    CABasicAnimation *fillAnimation = [CABasicAnimation animationWithKeyPath:@"path"];
    fillAnimation.duration = 4.0f;
    fillAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    fillAnimation.fillMode = kCAFillModeForwards;
    fillAnimation.fromValue = (id)Nopath.CGPath; //从中间轴
    fillAnimation.toValue = (id)fillpath.CGPath;//像两边拉伸
    [layer addAnimation:fillAnimation forKey:@"stretchingKey"];
}

2.曲线渐进出现,且图层颜色渐变

源码

    //遮罩路径
    UIBezierPath *maskpath = [UIBezierPath bezierPath];
    [maskpath moveToPoint:CGPointMake(0, 0)];
    for (int i = 0; i < 20; i ++) {
        if (i<5) {
            
            [maskpath addLineToPoint:CGPointMake(20*i, 20*i)];
            
        }else if(i <10)
        {
            [maskpath addLineToPoint:CGPointMake(15*i, 10*i)];
            
        }else{
            [maskpath addLineToPoint:CGPointMake(18*i, 6*i)];
        }
        
        if (i ==19) {
            [maskpath addLineToPoint:CGPointMake(18*i, 200)];
        }
    }
    //回到原点,封闭图形
    [maskpath addLineToPoint:CGPointMake(0, 200)];
    [maskpath addLineToPoint:CGPointMake(0, 0)];
    //遮罩图层
    CAShapeLayer *shadeLayer = [CAShapeLayer layer];
    shadeLayer.path = maskpath.CGPath;
    shadeLayer.fillColor = [UIColor greenColor].CGColor;
    //渐变图层
    CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    gradientLayer.frame = CGRectMake(0, 0, 0, 200);
    gradientLayer.startPoint = CGPointMake(0, 0);
    gradientLayer.endPoint = CGPointMake(0, 1);
    gradientLayer.colors = @[(__bridge id)[UIColor colorWithRed:166/255.0 green:206/255.0 blue:247/255.0 alpha:0.7].CGColor,(__bridge id)[UIColor colorWithRed:237/255.0 green:246/255.0 blue:253/255.0 alpha:0.5].CGColor];
    gradientLayer.locations = @[@(0.5f)];
    
    CALayer *baseLayer = [CALayer layer];
    baseLayer.frame = CGRectMake(20, 300, 18*19, 200);
    [baseLayer addSublayer:gradientLayer];
    [baseLayer setMask:shadeLayer];
    
    [self.view.layer addSublayer:baseLayer];
    
    CABasicAnimation *anmi1 = [CABasicAnimation animation];
    anmi1.keyPath = @"bounds";
    anmi1.duration = 5.0f;
    anmi1.toValue = [NSValue valueWithCGRect:CGRectMake(0, 0, 2*18*19, 200)];
    anmi1.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    anmi1.fillMode = kCAFillModeForwards;
    anmi1.autoreverses = NO;
    anmi1.removedOnCompletion = NO;
    [gradientLayer addAnimation:anmi1 forKey:@"bounds"];

3.逐渐绘制路径

源码

这是最简单的一种了

    //绘制路径
    UIBezierPath *strokepath = [UIBezierPath bezierPath];
    [strokepath moveToPoint:CGPointMake(0, 0)];
    for (int i = 0; i < 20; i ++) {
        if (i<5) {
            
            [strokepath addLineToPoint:CGPointMake(20*i, 20*i)];
            
        }else if(i <10)
        {
            [strokepath addLineToPoint:CGPointMake(15*i, 10*i)];
            
        }else{
            [strokepath addLineToPoint:CGPointMake(18*i, 6*i)];
        }
    }
    CAShapeLayer *layer2 = [CAShapeLayer layer];
    layer2.frame = CGRectMake(20, 500,18*19, 200);
    layer2.path = strokepath.CGPath;
    layer2.strokeColor = [UIColor greenColor].CGColor;
    layer2.lineWidth = 2.0f;
    layer2.fillColor = nil;
    layer2.lineJoin = kCALineCapRound;
    [self.view.layer addSublayer:layer2];
    
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    animation.duration = 5.0f;
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.fromValue = @(0.0);
    animation.toValue = @(1.0);
    [layer2 addAnimation:animation forKey:@"path"];

未完待续...