iOS 渐变色进度条

- (void)gradentWith:(CGRect)frame{

// 创建path

UIBezierPath *path = [UIBezierPath bezierPath];

// 添加路径[1条点(100,100)到点(200,100)的线段]到path

[path moveToPoint:CGPointMake(10 , 290)];

[path addLineToPoint:CGPointMake(250, 290)];

// 将path绘制出来

[path stroke];

//遮罩层

_progressLayer = [CAShapeLayer layer];

_progressLayer.frame = self.bounds;

_progressLayer.fillColor =  [[UIColor clearColor] CGColor];

_progressLayer.strokeColor=[UIColor redColor].CGColor;

_progressLayer.lineCap = kCALineCapRound;

_progressLayer.lineWidth = 10;

//渐变图层

CALayer * grain = [CALayer layer];

CAGradientLayer *gradientLayer =  [CAGradientLayer layer];

UIColor * fixColor  = [UIColor blueColor];

//    UIColor * fixColor  = [UIColor colorWithRed:48/255.0 green:149/255.0 blue:215/255.0 alpha:1];

UIColor * preColor  = [UIColor whiteColor];

gradientLayer.frame = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height);

[gradientLayer setColors:[NSArray arrayWithObjects:(id)[preColor CGColor],(id)[fixColor CGColor], nil]];

// 设置颜色的分割点

[gradientLayer setLocations:@[@0.01,@1]];

// 开始点

[gradientLayer setStartPoint:CGPointMake(0, 0)];

// 结束点

[gradientLayer setEndPoint:CGPointMake(1, 1)];

[grain addSublayer:gradientLayer];

[grain setMask:_progressLayer];

[self.layer addSublayer:grain];

//增加动画

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

pathAnimation.duration = 6;

pathAnimation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];

pathAnimation.fromValue=[NSNumber numberWithFloat:0.0f];

pathAnimation.toValue=[NSNumber numberWithFloat:1.0f];

pathAnimation.autoreverses=NO;

pathAnimation.repeatCount = INFINITY;

[_progressLayer addAnimation:pathAnimation forKey:@"strokeEndAnimation"];

_progressLayer.path=path.CGPath;

}