根据 PagerSlidingTabStrip 项目修改而来，轻松实现**「知乎客户端」指示器切换时文字颜色或图片透明度**渐变的效果，同时方便给顶部选择的 Tab 添加 BadgeView 显示红点。
如果你之前使用过 PagerSlidingTabStrip 这个库，那么学习使用这个库的学习成本很低，设置的方法跟 PagerSlidingTabStrip 完全相同。
项目代码解析见博客
使用 android-viewBadge 添加红点，滑动时 Tab 颜色改变效果：
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