Android学习之“BottomNavigationView+ViewPager”实现底部导航与翻页
一、效果图
未使用app:labelVisibilityMode=“labeled”
二、实现步骤
1. 创建一个新的项目NavigationTest
2. 在app文件夹下的build.gradle中添加BottomNavigationView所需要的依赖库
implementation 'com.android.support:design:28.0.0' //底部导航栏
3. 在res文件夹下面新建menu文件夹，并新建bottom_navigation_view.xml作为导航栏的菜单文件，内含导航栏的选项图标和选项文字。将图标资源放入drawable文件夹下
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/item_bottom_navigation_view_home"
android:icon="@drawable/home"
android:title="首页" />
<item
android:id="@+id/item_bottom_navigation_view_pt_job"
android:icon="@drawable/pt_job"
android:title="兼职" />
<item
android:id="@+id/item_bottom_navigation_view_message"
android:icon="@drawable/message"
android:title="消息" />
<item
android:id="@+id/item_bottom_navigation_view_personal"
android:icon="@drawable/personal"
android:title="我的" />
</menu>
4. 在values/colors.xml添加选中与未选中的颜色
<!--底部导航栏颜色-->
<color name="bottom_navigation_view_checked">#1874CD</color>
<color name="bottom_navigation_view_unchecked">#7EC0EE</color>
5. 在drawable文件夹下新建bottom_navigation_view_selector.xml作为底部导航栏样式的配置文件。
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:color="@color/bottom_navigation_view_checked" android:state_checked="true" />
<item android:color="@color/bottom_navigation_view_unchecked" android:state_checked="false" />
</selector>
6. 修改主函数的布局文件activity_main.xml BottomNavigationView在底部，ViewPager填满上方剩余部分。
<?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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.v4.view.ViewPager
android:id="@+id/activity_main_view_pager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
</android.support.v4.view.ViewPager>
<android.support.design.widget.BottomNavigationView
android:id="@+id/activity_main_bottom_navigation_view"
android:layout_width="match_parent"
android:layout_height="52dp"
app:itemBackground="@null"
app:itemIconTint="@drawable/bottom_navigation_view_selector"
app:itemTextColor="@drawable/bottom_navigation_view_selector"
app:labelVisibilityMode="labeled"
app:menu="@menu/bottom_navigation_view">
<!--app:labelVisibilityMode="labeled"该属性固定住图标与文字，
具体效果参见上方效果图展示-->
</android.support.design.widget.BottomNavigationView>
</LinearLayout>
7. 准备填充ViewPager的Fragment
A. 在values/strings.xml字符串资源文件中添加以下字符串
<string name="s_bottom_navigation_view_home">首页</string>
<string name="s_bottom_navigation_view_message">消息</string>
<string name="s_bottom_navigation_view_personal">我的</string>
<string name="s_bottom_navigation_view_pt_job">兼职</string>
B. Fragment的布局文件（以首页Fragment为例）
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="@string/s_bottom_navigation_view_home"/>
</android.support.constraint.ConstraintLayout>
C. Fragment的Java文件（以首页Fragment为例）
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class HomeFragment extends Fragment {
public static HomeFragment newInstance(){
HomeFragment indexFragment = new HomeFragment();
return indexFragment;
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_home,container,false);
return view;
}
}
8. 新建ViewPagerAdapterForNav.java 作为ViewPager的适配器
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import java.util.ArrayList;
import java.util.List;
public class ViewPagerAdapterForNav extends FragmentStatePagerAdapter {
//碎片集合
private List<Fragment> mFragments = new ArrayList<>();
public ViewPagerAdapterForNav(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
if (mFragments == null){
return 0;
}else{
return mFragments.size();
}
}
@Override
public Fragment getItem(int i) {
return mFragments.get(i);
}
public void setFragments(List<Fragment> fragments) {
this.mFragments = fragments;
notifyDataSetChanged();
}
}
9. 修改MainActivity.java完成相应功能
import android.support.design.widget.BottomNavigationView;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
//碎片集合
List<Fragment> mFragments;
//组件
private BottomNavigationView mBottomNavigationView;
private ViewPager mViewPager;
//适配器
private ViewPagerAdapterForNav mViewPagerAdapterForNav;
private MenuItem menuItem;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//隐藏标题栏
android.support.v7.app.ActionBar actionBar = getSupportActionBar();
actionBar.hide();
//实例化组件
initElement();
//初始化碎片集合
initFragments();
//导航栏与ViewPager联动
//给底部导航栏和ViewPager设置监听器
mBottomNavigationView.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
if (menuItem != null) {
menuItem.setChecked(false);
} else {
mBottomNavigationView.getMenu().getItem(0).setChecked(false);
}
menuItem = mBottomNavigationView.getMenu().getItem(position);
menuItem.setChecked(true);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
//为ViewPager设置适配器
mViewPagerAdapterForNav = new ViewPagerAdapterForNav(getSupportFragmentManager());
mViewPager.setAdapter(mViewPagerAdapterForNav);
mViewPagerAdapterForNav.setFragments(mFragments);
}
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener = new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem item) {
menuItem = item;
switch (item.getItemId()) {
case R.id.item_bottom_navigation_view_home:
mViewPager.setCurrentItem(0);
return true;
case R.id.item_bottom_navigation_view_pt_job:
mViewPager.setCurrentItem(1);
return true;
case R.id.item_bottom_navigation_view_message:
mViewPager.setCurrentItem(2);
return true;
case R.id.item_bottom_navigation_view_personal:
mViewPager.setCurrentItem(3);
return true;
}
return false;
}
};
private void initElement(){
mBottomNavigationView = (BottomNavigationView)findViewById(R.id.activity_main_bottom_navigation_view);
mViewPager = (ViewPager)findViewById(R.id.activity_main_view_pager);
}
private void initFragments(){
mFragments = new ArrayList<>();
mFragments.add(HomeFragment.newInstance());
mFragments.add(Pt_jobFragment.newInstance());
mFragments.add(MessageFragment.newInstance());
mFragments.add(PersonalFragment.newInstance());
}
}