iOS UISlider设置滑块隐藏(透明)

    self.slider = [[XBVideoSlider alloc]init];

    self.slider.frame = CGRectMake(_progressLabel.right, 28*gScale, 480*gScale, 5*gScale);

    self.slider.value = 0.0f;

    self.slider.tintColor = kClearColor;

    self.slider.thumbTintColor = kClearColor;

    self.slider.maximumTrackTintColor = [kWhiteColor colorWithAlphaComponent:0.4];

    self.slider.minimumTrackTintColor = kWhiteColor;

//    UIImage * thumbImage =  [UIImage imageNamed:@"XBVideoPlayer_ProgressMaxThumb"]

    //[UIImage imageNamed:@"XBVideoPlayer_ProgressMaxThumb"]

    //设置进度条背景图片

//    [_slider setThumbImage:thumbImage forState:UIControlStateNormal];