使用Bottom Navigation Activity实现Android底部导航栏

最近看到Android Studio里新建Activity时共选择模板中Bottom Navigation Activity可以实现Android底部导航的效果，在网上没啥参考资料，于是自己搞个教程方便大家学习指正哈。话不多说，直接效果图:（Android Studio：2.3.1）







步骤：

1.新建Bottom Navigation Activity,包含layout文件activity_navigation.xml和class文件NavigationActivity：

   



activity_navigation.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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.lin.coursetwo.NavigationActivity">

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

<TextView
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" />

</FrameLayout>

<android.support.design.widget.BottomNavigationView
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" />

</LinearLayout>

NavigationActivity.java代码：

package com.lin.coursetwo;

import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;

import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import android.widget.TextView;

import com.lin.coursetwo.fragment.FragmentOne;
import com.lin.coursetwo.fragment.FragmentThree;
import com.lin.coursetwo.fragment.FragmentTwo;

public class NavigationActivity extends AppCompatActivity {

private TextView mTextMessage;
private FragmentOne fragmentOne;
private FragmentTwo fragmentTwo;
private FragmentThree fragmentThree;
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
mTextMessage.setText(R.string.title_home);
showNav(R.id.navigation_home);
return true;
case R.id.navigation_dashboard:
mTextMessage.setText(R.string.title_dashboard);
showNav(R.id.navigation_dashboard);
return true;
case R.id.navigation_notifications:
mTextMessage.setText(R.string.title_notifications);
showNav(R.id.navigation_notifications);
return true;
}
return false;
}

};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_navigation);
init();
mTextMessage = (TextView) findViewById(R.id.message);
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}

//init（）用来初始化组件
private void init(){
fragmentOne=new FragmentOne();
fragmentTwo=new FragmentTwo();
fragmentThree=new FragmentThree();
FragmentTransaction beginTransaction=getFragmentManager().beginTransaction();
beginTransaction.add(R.id.content,fragmentOne).add(R.id.content,fragmentTwo).add(R.id.content,fragmentThree);//开启一个事务将fragment动态加载到组件
beginTransaction.hide(fragmentOne).hide(fragmentTwo).hide(fragmentThree);//隐藏fragment
beginTransaction.addToBackStack(null);//返回到上一个显示的fragment
beginTransaction.commit();//每一个事务最后操作必须是commit（），否则看不见效果
showNav(R.id.navigation_home);
}

private void showNav(int navid){
FragmentTransaction beginTransaction=getFragmentManager().beginTransaction();
switch (navid){
case R.id.navigation_home:
beginTransaction.hide(fragmentTwo).hide(fragmentThree);
beginTransaction.show(fragmentOne);
beginTransaction.addToBackStack(null);
beginTransaction.commit();
break;
case R.id.navigation_dashboard:
beginTransaction.hide(fragmentOne).hide(fragmentThree);
beginTransaction.show(fragmentTwo);
beginTransaction.addToBackStack(null);
beginTransaction.commit();
break;
case R.id.navigation_notifications:
beginTransaction.hide(fragmentTwo).hide(fragmentOne);
beginTransaction.show(fragmentThree);
beginTransaction.addToBackStack(null);
beginTransaction.commit();
break;
}
}

}

2.新建三个Fragment类：FragmentOne、FragmentTwo、FragmentThree和对应的三个layout文件：fragment_one.xml、fragment_two.xml、fragment_three.xml

FragmentOne代码：

package com.lin.coursetwo.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.lin.coursetwo.R;

public class FragmentOne extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_one,container,false);
return view;
}
}

FragmentTwo代码：

package com.lin.coursetwo.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.lin.coursetwo.R;

public class FragmentTwo extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_two,container,false);
return view;
}
}

FragmentThree代码：

package com.lin.coursetwo.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.lin.coursetwo.R;

public class FragmentThree extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_three,container,false);
return view;
}
}

fr
c23a
agment_one.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#4BAE4F"
android:gravity="center">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="这是第一个页面"
android:textSize="30dp"
android:textColor="#ffffff"
android:gravity="center"/>

</LinearLayout>
</LinearLayout>

fragment_two.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#785447"
android:gravity="center">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="这是第二个页面"
android:textSize="30dp"
android:textColor="#ffffff"
android:gravity="center"/>

</LinearLayout>
</LinearLayout>

fragment_three.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#00BBD3"
android:gravity="center">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="这是第三个页面"
android:textSize="30dp"
android:textColor="#ffffff"
android:gravity="center"/>

</LinearLayout>
</LinearLayout>

至此：一个简易的android底部导航功能就实现了，当然还有许多需要修改的地方，但整体的架构已经出来，希望大家能够参考指正，给我们一个新思路。