底部导航栏
作者：互联网
1.添加相应的文件
a.先引入导航栏的依赖
implementation 'com.android.support:design:+'
b.准备导航栏的图片素材（我这里的是4个主页，我准备了8个，4个为true的，4个为false的）
c.创建一个menu文件，然后再里面创建一个Menu resource file文件
1 <?xml version="1.0" encoding="utf-8"?> 2 <menu xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto"> 4 <item 5 android:id="@+id/menu_home" 6 android:title="首页" 7 app:showAsAction="ifRoom" 8 android:enabled="true" 9 android:icon="@drawable/home_t"/> 10 <item 11 android:id="@+id/menu_classification" 12 android:title="分类" 13 app:showAsAction="ifRoom" 14 android:enabled="true" 15 android:icon="@drawable/classification_f"/> 16 <item 17 android:id="@+id/menu_shoppingcart" 18 android:title="购物车" 19 app:showAsAction="ifRoom" 20 android:enabled="true" 21 android:icon="@drawable/shoppingcart_f"/> 22 <item 23 android:id="@+id/menu_personal" 24 android:title="我的" 25 app:showAsAction="ifRoom" 26 android:enabled="true" 27 android:icon="@drawable/personal_f"/> 28 </menu>
c.在drawable中创建一个bottom_navigtion_item_selector.xml文件
1 <?xml version="1.0" encoding="utf-8"?> 2 <selector xmlns:android="http://schemas.android.com/apk/res/android"> 3 4 <item android:color="#157AE2" android:state_checked="true" /> 5 <item android:color="#CCCCCC" android:state_checked="false" /> 6 </selector>
d.创建一个绑定显示未选中导航栏描述字的类
1 public class BottomNavigationViewHelper {
2 @SuppressLint("RestrictedApi")
3 public static void disableShiftMode(BottomNavigationView view) {
4 BottomNavigationMenuView menuView = (BottomNavigationMenuView) view.getChildAt(0);
5 try {
6 Field shiftingMode = menuView.getClass().getDeclaredField("labelVisibilityMode");
7 shiftingMode.setAccessible(true);
8 shiftingMode.setInt(menuView, 1);//labelVisibilityMode
9 // shiftingMode.setBoolean(menuView, false);//mShiftingMode
10 shiftingMode.setAccessible(false);
11 for (int i = 0; i < menuView.getChildCount(); i++) {
12 BottomNavigationItemView item = (BottomNavigationItemView) menuView.getChildAt(i);
13 item.setShifting(false);
14 item.setChecked(item.getItemData().isChecked());
15 }
16 } catch (NoSuchFieldException e) {
17 Log.e("BNVHelper", "Unable to get shift mode field", e);
18 } catch (IllegalAccessException e) {
19 Log.e("BNVHelper", "Unable to change value of shift mode", e);
20 }
21 }
22 }
分别加入4个Fragment以及布局文件（这里我发其中的一个碎片的代码）
1 public class ClassificationFragment extends Fragment {
2 private View view;
3 @Nullable
4 @Override
5 public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
6 view = inflater.inflate(R.layout.fragment_classification,container,false);
7
8 return view;
9 }
10 }
MianActivity的引用（直接贴出MainActivity的代码）
1 public class MainActivity extends AppCompatActivity {
2 private BottomNavigationView bottomNavigationView;
3 private int lastIndex;
4 List<Fragment> mFragment;
5 private Toolbar toolbar;
6 @Override
7 protected void onCreate(Bundle savedInstanceState) {
8 super.onCreate(savedInstanceState);
9 setContentView(R.layout.activity_main);
10 initDate();
11 initBottomNavigation();
12 }
13
14 private void initDate(){
15 mFragment = new ArrayList<>();
16 mFragment.add(new HomeFragment());
17 mFragment.add(new ClassificationFragment());
18 mFragment.add(new ShoppingCartFragment());
19 mFragment.add(new PersonalFragment());
20 setFragmentPosition(0);
21 }
22
23 private void initBottomNavigation(){
24 bottomNavigationView = findViewById(R.id.bv_bottomNavigation);
25 bottomNavigationView.setItemIconTintList(null); //取消图片默认颜色
26 BottomNavigationViewHelper.disableShiftMode(bottomNavigationView); //显示未选中导航栏的描述字
27 bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
28 @Override
29 public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
30 resetToDefaultIcon();//重置到默认不选中图片
31 switch (menuItem.getItemId()){
32 case R.id.menu_home:
33 menuItem.setIcon(R.drawable.home_t); //设置选中的图片
34 setFragmentPosition(0); //选中的碎片
35 break;
36 case R.id.menu_classification:
37 menuItem.setIcon(R.drawable.classification_t); //设置选中的图片
38 setFragmentPosition(1);
39 break;
40 case R.id.menu_shoppingcart:
41 menuItem.setIcon(R.drawable.shoppingcart_t); //设置选中的图片
42 setFragmentPosition(2);
43 break;
44 case R.id.menu_personal:
45 menuItem.setIcon(R.drawable.personal_t); //设置选中的图片
46 setFragmentPosition(3);
47 break;
48 default:break;
49 }
50 return true;
51 }
52 });
53 }
54
55 //重置图标
56 private void resetToDefaultIcon() {
57 MenuItem home = bottomNavigationView.getMenu().findItem(R.id.menu_home);
58 home.setIcon(R.drawable.home_f);
59 MenuItem classification = bottomNavigationView.getMenu().findItem(R.id.menu_classification);
60 classification.setIcon(R.drawable.classification_f);
61 MenuItem shoppingcart = bottomNavigationView.getMenu().findItem(R.id.menu_shoppingcart);
62 shoppingcart.setIcon(R.drawable.shoppingcart_f);
63 MenuItem personal = bottomNavigationView.getMenu().findItem(R.id.menu_personal);
64 personal.setIcon(R.drawable.personal_f);
65
66 }
67
68 //设置选中的Fragment
69 private void setFragmentPosition(int position){
70 FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
71 Fragment currentFragment = mFragment.get(position);
72 Fragment lastFragment = mFragment.get(lastIndex);
73 lastIndex = position;
74 fragmentTransaction.hide(lastFragment);
75 if(!currentFragment.isAdded()){
76 getSupportFragmentManager().beginTransaction().remove(currentFragment).commit();
77 fragmentTransaction.add(R.id.ll_frameLayout,currentFragment);
78 }
79 fragmentTransaction.show(currentFragment);
80 fragmentTransaction.commitAllowingStateLoss();
81 }
82 }
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:app="http://schemas.android.com/apk/res-auto" 4 xmlns:tools="http://schemas.android.com/tools" 5 android:layout_width="match_parent" 6 android:layout_height="match_parent"> 7 8 <FrameLayout 9 android:id="@+id/ll_frameLayout" 10 android:layout_width="match_parent" 11 android:layout_height="match_parent" 12 android:layout_above="@id/bv_bottomNavigation" /> 13 14 <com.google.android.material.bottomnavigation.BottomNavigationView 15 android:id="@+id/bv_bottomNavigation" 16 android:layout_width="match_parent" 17 android:layout_height="wrap_content" 18 android:layout_alignParentBottom="true" 19 android:background="@color/colorWhite" 20 app:itemIconTint="@drawable/bottom_navigation_item_selector" 21 app:itemTextColor="@drawable/bottom_navigation_item_title" 22 app:menu="@menu/main_bottom_navigation"> 23 24 </com.google.android.material.bottomnavigation.BottomNavigationView> 25 </RelativeLayout>
标签：导航,menu,private,底部,drawable,bottomNavigationView,id,setIcon 来源： https://www.cnblogs.com/Mr-Deng/p/11583336.html