底部导航之TabLayout+ViewPager

这里简单记录一下通过TabLayout+ViewPager来实现Android底部导航栏。

布局

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <include layout="@layout/fragment_content"/> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <android.support.v4.view.ViewPager android:id="@+id/view_pager" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1"></android.support.v4.view.ViewPager> <android.support.design.widget.TabLayout android:id="@+id/tab_layout" android:layout_width="match_parent" android:layout_height="56dp" app:tabBackground="@color/white" app:tabIndicatorHeight="0dp" app:tabSelectedTextColor="@color/colorPrimary" app:tabTextAppearance="@style/tabTextSizeStyle" app:tabTextColor="@color/black_1"></android.support.design.widget.TabLayout> </LinearLayout> </RelativeLayout>

代码

mViewPager = (ViewPager) view.findViewById(R.id.view_pager); mTabLayout = (TabLayout) view.findViewById(R.id.tab_layout); initTabList(); mAdapter = new TabLayoutFragmentAdapter(getChildFragmentManager(), mTabList, getActivity(), mFragments, mTabImgs); mViewPager.setAdapter(mAdapter); mViewPager.setCurrentItem(0); mTabLayout.setupWithViewPager(mViewPager); mTabLayout.setTabMode(TabLayout.MODE_FIXED);//设置TabLayout的模式 for (int i = 0; i < mTabLayout.getTabCount(); i++) { mTabLayout.getTabAt(i).setCustomView(mAdapter.getTabView(i)); } mTabLayout.addOnTabSelectedListener(this);//设置TabLayout的选中监听

这里需要注意的就是TabLayout的使用。TabLayou配合ViewPager使用。要用 mTabLayout.setupWithViewPager(mViewPager);使二者联系起来。另外这里面使用的是customView，当然TabLayout自带方法也可实现icon+text的效果。也就是效果：TabLayout + ViewPager 2

根据Tab选中状态显示Tab键效果

@Override public void onTabSelected(TabLayout.Tab tab) { setTabSelectedState(tab); } @Override public void onTabUnselected(TabLayout.Tab tab) { setTabUnSelectedState(tab); } @Override public void onTabReselected(TabLayout.Tab tab) { } private void setTabSelectedState(TabLayout.Tab tab) { View customView = tab.getCustomView(); TextView tabText = (TextView) customView.findViewById(R.id.tv_tab_text); ImageView tabIcon = (ImageView) customView.findViewById(R.id.iv_tab_icon); tabText.setTextColor(ContextCompat.getColor(getActivity(), R.color.colorPrimary)); String s = tabText.getText().toString(); if (getString(R.string.item_home).equals(s)) { tabIcon.setImageResource(R.drawable.home_fill); } else if (getString(R.string.item_location).equals(s)) { tabIcon.setImageResource(R.drawable.location_fill); } else if (getString(R.string.item_like).equals(s)) { tabIcon.setImageResource(R.drawable.like_fill); } else if (getString(R.string.item_person).equals(s)) { tabIcon.setImageResource(R.drawable.person_fill); } } private void setTabUnSelectedState(TabLayout.Tab tab) { View customView = tab.getCustomView(); TextView tabText = (TextView) customView.findViewById(R.id.tv_tab_text); ImageView tabIcon = (ImageView) customView.findViewById(R.id.iv_tab_icon); tabText.setTextColor(ContextCompat.getColor(getActivity(), R.color.black_1)); String s = tabText.getText().toString(); if (getString(R.string.item_home).equals(s)) { tabIcon.setImageResource(R.drawable.home); } else if (getString(R.string.item_location).equals(s)) { tabIcon.setImageResource(R.drawable.location); } else if (getString(R.string.item_like).equals(s)) { tabIcon.setImageResource(R.drawable.like); } else if (getString(R.string.item_person).equals(s)) { tabIcon.setImageResource(R.drawable.person); } }

这里面不用设置defaultFragment，TabLayout会默认显示第一个；

另外，这里也贴出使用TabLayout自带方法来实现效果代码

值得说的是，自带方法不能自定义icon和text的间距。用起来很方便，但是可能不是你要求的那个尺寸大小。我没有去深究这里面的源码。如果有人知道这个自带方法怎么改变的，也请告知一下。

mViewPager = (ViewPager) view.findViewById(R.id.view_pager); mTabLayout = (TabLayout) view.findViewById(R.id.tab_layout); initTabList(); mAdapter = new TabLayoutFragment2Adapter(getChildFragmentManager(), mTabList, getActivity(), mFragments, mTabImgs); mViewPager.setAdapter(mAdapter); mViewPager.setCurrentItem(0); mTabLayout.setupWithViewPager(mViewPager); mTabLayout.setTabMode(TabLayout.MODE_FIXED); // for (int i = 0; i < mTabLayout.getTabCount(); i++) { // mTabLayout.getTabAt(i).setCustomView(mAdapter.getTabView(i)); // } mTabLayout.addOnTabSelectedListener(this); // mViewPager.setCurrentItem(0); mTabLayout.getTabAt(0).setIcon(R.drawable.home_fill);//自有方法添加icon mTabLayout.getTabAt(1).setIcon(R.drawable.location); mTabLayout.getTabAt(2).setIcon(R.drawable.like); mTabLayout.getTabAt(3).setIcon(R.drawable.person);

Tab切换

@Override public void onTabSelected(TabLayout.Tab tab) { // setTabSelectedState(tab);//这个也无需使用 resetTabIcon(); int position = tab.getPosition(); Log.e("Kevin", "position--->" + position); switch (position) { case 0: tab.setIcon(R.drawable.home_fill); break; case 1: tab.setIcon(R.drawable.location_fill); break; case 2: tab.setIcon(R.drawable.like_fill); break; case 3: tab.setIcon(R.drawable.person_fill); break; } } private void resetTabIcon() { mTabLayout.getTabAt(0).setIcon(R.drawable.home); mTabLayout.getTabAt(1).setIcon(R.drawable.location); mTabLayout.getTabAt(2).setIcon(R.drawable.like); mTabLayout.getTabAt(3).setIcon(R.drawable.person); }

说明：这几篇文章没有过多的文字叙述，因为这些东西也不是很难，而且都是常用的，相信很多人都了如指掌了，多说亦是废话，直接上代码看的反而更清楚。