+ (WGradientProgress *)sharedInstance;/***  the main interface to show WGradientProgress obj, position is WProgressPosDown by default.**  @param parentView which view to be attach*/
- (void)showOnParent:(UIView *)parentView;/***  the main interface to show WGradientProgress obj**  @param parentView which view to be attach*  @param pos        up or down*/
- (void)showOnParent:(UIView *)parentView position:(WProgressPos)pos;/***  the main interface to hide WGradientProgress obj*/
- (void)hide;

    if (self.gradLayer == nil) {self.gradLayer = [CAGradientLayer layer];self.gradLayer.frame = self.bounds;//尺寸要与view的layer一致}self.gradLayer.startPoint = CGPointMake(0, 0.5);self.gradLayer.endPoint = CGPointMake(1, 0.5);//create colors, important sectionNSMutableArray *colors = [NSMutableArray array];for (NSInteger deg = 0; deg <= 360; deg += 5) {UIColor *color;color = [UIColor colorWithHue:1.0 * deg / 360.0saturation:1.0brightness:1.0alpha:1.0];[colors addObject:(id)[color CGColor]];}[self.gradLayer setColors:[NSArray arrayWithArray:colors]];

/***  here I use timer to circularly move colors*/
- (void)setupTimer
{CGFloat interval = 0.03;if (self.timer == nil) {self.timer = [NSTimer timerWithTimeInterval:interval target:selfselector:@selector(timerFunc)userInfo:nil repeats:YES];}[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSDefaultRunLoopMode];
}/***  rearrange color array*/
- (void)timerFunc
{CAGradientLayer *gradLayer = self.gradLayer;NSMutableArray *copyArray = [NSMutableArray arrayWithArray:[gradLayer colors]];UIColor *lastColor = [copyArray lastObject];[copyArray removeLastObject];if (lastColor) {[copyArray insertObject:lastColor atIndex:0];}[self.gradLayer setColors:copyArray];
}

- (void)startTimer
{//start timer[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSDefaultRunLoopMode];[self.timer setFireDate:[NSDate date]];
}

/***  here we just pause timer, rather than stopping forever.*  NOTE: [timer invalidate] is not fit here.*/
- (void)pauseTimer
{[self.timer setFireDate:[NSDate distantFuture]];
}

[self.timer invalidate]

CALayer *layer = new
layer.mask = _maskLayer;
layer.visualSection = _maskLayer.bounds;

    self.mask = [CALayer layer];[self.mask setFrame:CGRectMake(self.gradLayer.frame.origin.x, self.gradLayer.frame.origin.y,self.progress * self.width, self.height)];self.mask.borderColor = [[UIColor blueColor] CGColor];self.mask.borderWidth = 2;[self.gradLayer setMask:self.mask];[self.layer addSublayer:self.gradLayer];

- (void)setProgress:(CGFloat)progress
{if (progress < 0) {progress = 0;}if (progress > 1) {progress = 1;}_progress = progress;CGFloat maskWidth = progress * self.width;self.mask.frame = CGRectMake(0, 0, maskWidth, self.height);
}