开发环境:
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效果图:
《《《代码在底部》》》
1,新建项目
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2,新建若干Fragment,内容一样,改一下显示出来的Text,名字分别为test1Fragment,test2Fragment,test3Fragment,默认TextView的Text属性分别设置为Fragment1内容,Fragment2内容,Fragment3内容,以示区分
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3,拖拽一个FrameLayout
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4,拖拽一个BottomNavigationView
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5,调整代码
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6,新建一个菜单资源给BottomNavigationView使用
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7,BottomNavigationView和新建的菜单项关联
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8,进一步调整代码
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9,MainActivity中的代码
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10,红色部分导入类即可解决
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代码如下:
1,nav_menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/navigation_home"
android:icon="@android:drawable/ic_dialog_map"
android:title="Frame1" />
<item
android:id="@+id/navigation_tools"
android:icon="@android:drawable/ic_menu_compass"
android:title="Frame2" />
<item
android:id="@+id/navigation_play"
android:icon="@android:drawable/ic_menu_gallery"
android:title="Frame3" />
</menu>
2,activity_main.xml
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
tools:ignore="ExtraText">
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/nav_menu"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_menu"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:menu="@menu/nav_menu"
tools:layout_height="50dp" />
</RelativeLayout>
3,fragment_test1.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".test1Fragment">
<!-- TODO: Update blank fragment layout -->
<TextView
android:id="@+id/text1Fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Fragment1内容" />
</FrameLayout>
4,MainActivity.java
package com.example.bottomnavigationviewstudy;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import android.os.Bundle;
import android.view.MenuItem;
import com.google.android.material.bottomnavigation.BottomNavigationView;
import com.google.android.material.navigation.NavigationBarView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
ArrayList<Fragment> mFragments = new ArrayList<Fragment>();
test1Fragment t1f = new test1Fragment();
test2Fragment t2f = new test2Fragment();
test3Fragment t3f = new test3Fragment();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BottomNavigationView navView = findViewById(R.id.nav_menu);
mFragments.add(t1f);
mFragments.add(t2f);
mFragments.add(t3f);
//设置默认加载视图
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new test1Fragment()).commit();
// navView 点击事件
navView.setOnItemSelectedListener(new NavigationBarView.OnItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
String a = (String) item.getTitle();
//判断是哪个item被点击了
switch (a) {
case "Frame2":
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new test2Fragment()).commit();
break;
case "Frame3":
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new test3Fragment()).commit();
break;
default:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new test1Fragment()).commit();
break;
}
item.setChecked(true);
return true;
}
});
}
}