项目中使用XTabLayout+ViewPager实现选项卡,XTab支持定义下滑指示器的长度
<com.androidkun.xtablayout.XTabLayout android:id="@+id/tabs" android:layout_width="match_parent" android:layout_height="43dp" app:tabGravity="center" app:xTabBackgroundColor="@color/white" app:xTabSelectedBackgroundColor="@color/white" app:xTabIndicatorColor="@color/dx_blue_color" app:xTabIndicatorHeight="4dp" app:xTabIndicatorWidth="55dp" app:tabMinWidth="80dp"
app:tabMode="scrollable"
app:tabSelectedTextColor="@color/blue_color"
app:tabTextAppearance="@style/HomeMyTablayoutTextAppearance"/>
但是发现调用setOnTabSelectedListener点击菜单时没有切换fragment，不监听则正常。查看源码发现OnTabSelectedListener中的onTabSelected方法有个默认实现：
mPageChangeListener.reset(); viewPager.addOnPageChangeListener(mPageChangeListener); // Now we'll add a tab selected listener to set ViewPager's current item setOnTabSelectedListener(new XTabLayout.ViewPagerOnTabSelectedListener(viewPager));
/** * A {@link TabLayout.OnTabSelectedListener} class which contains the necessary calls back * to the provided {@link ViewPager} so that the tab position is kept in sync. */ public static class ViewPagerOnTabSelectedListener implements XTabLayout.OnTabSelectedListener { private final ViewPager mViewPager; public ViewPagerOnTabSelectedListener(ViewPager viewPager) { mViewPager = viewPager; } @Override public void onTabSelected(XTabLayout.Tab tab) { mViewPager.setCurrentItem(tab.getPosition()); } @Override public void onTabUnselected(XTabLayout.Tab tab) { // No-op } @Override public void onTabReselected(XTabLayout.Tab tab) { // No-op }
}
所以自己监听OnTabSelectedListener事件时需要在onTabSelected方法中调用ViewPager的setCurrentItem方法。
tabLayout.setOnTabSelectedListener(new XTabLayout.OnTabSelectedListener() { @Override public void onTabSelected(XTabLayout.Tab tab) { viewPager.setCurrentItem(tab.getPosition()); if (tab.getPosition() == 0) {
} else if (tab.getPosition() == 1) {
} } @Override public void onTabUnselected(XTabLayout.Tab tab) { } @Override public void onTabReselected(XTabLayout.Tab tab) { }
});
可以使用addListener或者模版方法进行扩展，这样具体的set的Listener只需要关注新增监听逻辑即可。