BottomNavigationView+fragment 实现底部菜单栏

第三方大神：GitHub - aurelhubert/ahbottomnavigation，GitHub - roughike/BottomBar， Ashok-Varma/BottomNavigation。

直接上代码：

activity_main：

xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.administrator.tablayout.MainActivity">

            android:id="@+id/content"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:visibility="visible">

                    android:id="@+id/message"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="@dimen/activity_vertical_margin"
            android:layout_marginLeft="@dimen/activity_horizontal_margin"
            android:layout_marginRight="@dimen/activity_horizontal_margin"
            android:layout_marginTop="@dimen/activity_vertical_margin"
            android:text="@string/title_home"
            android:visibility="gone" />

    

            android:id="@+id/vp_content"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:visibility="gone">

    

            android:id="@+id/navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="?android:attr/windowBackground"
        app:menu="@menu/navigation" />

MainActivity代码：

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import android.widget.FrameLayout;
import android.widget.TextView;

import com.example.administrator.tablayout.fragment.BlankFragment;
import com.example.administrator.tablayout.fragment.FragmentOne;
import com.example.administrator.tablayout.fragment.FragmentTwo;
import com.example.administrator.tablayout.fragment.ItemFragment;
import com.example.administrator.tablayout.fragment.PlusOneFragment;

public class MainActivity extends AppCompatActivity {

    private TextView mTextMessage;
    private BlankFragment blankFragment;
    private ItemFragment itemFragment;
    private PlusOneFragment plusOneFragment;
    private FrameLayout fl;
    private Fragment[] fragments;
    private int lastShowFragment = 0;

    private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
            = new BottomNavigationView.OnNavigationItemSelectedListener() {

        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()) {
                case R.id.navigation_home:
                    if (lastShowFragment != 0) {
                        switchFrament(lastShowFragment, 0);
                        lastShowFragment = 0;
                    }
                    return true;
                case R.id.navigation_dashboard:
                    if (lastShowFragment != 1) {
                        switchFrament(lastShowFragment, 1);
                        lastShowFragment = 1;
                    }
                    return true;
                case R.id.navigation_notifications:
                    if (lastShowFragment != 2) {
                        switchFrament(lastShowFragment, 2);
                        lastShowFragment = 2;
                    }
                    return true;
            }
            return false;
        }

    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        fl = (FrameLayout) findViewById(R.id.content);
        mTextMessage = (TextView) findViewById(R.id.message);
        BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
        navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
        initFragments();

    }

    /**
     * 切换Fragment
     *
     * @param lastIndex 上个显示Fragment的索引
     * @param index     需要显示的Fragment的索引
     */
    public void switchFrament(int lastIndex, int index) {

        android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

        transaction.hide(fragments[lastIndex]);

        if (!fragments[index].isAdded()) {

            transaction.add(R.id.content, fragments[index]);
        }

        transaction.show(fragments[index]).commitAllowingStateLoss();
    }

    private void initFragments() {

        FragmentOne one = new FragmentOne();
        FragmentTwo one2 = new FragmentTwo();
        FragmentOne one3 = new FragmentOne();

        fragments = new Fragment[]{one, one2, one3};
        lastShowFragment = 0;
        getSupportFragmentManager()
                .beginTransaction()
                .add(R.id.content, one)
                .show(one)
                .commit();
    }

}

over很简单。