TabHost+Fragment

完成TabHost+Fragment的主界面导航

Fragment

5个fragment，列举其一：

import android.annotation.SuppressLint;
import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment1 extends Fragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @SuppressLint("InflateParams")
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return
                inflater.inflate(R.layout.fragment1, null);
    }
}

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ImageView
        android:id="@+id/imageview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scaleType="fitCenter"
        android:src="@drawable/xianjian01" >
    </ImageView>
</LinearLayout>

继承类：

import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.fragment.app.FragmentManager;
import androidx.lifecycle.Lifecycle;
import androidx.viewpager2.adapter.FragmentStateAdapter;

import java.util.List;

/**
 * 适配器对象
 * @author 白
 */
public class MyFragmentPagerAdapter extends FragmentStateAdapter {
    private final List<Fragment> fragmentList;

    public MyFragmentPagerAdapter(@NonNull FragmentManager fragmentManager, @NonNull Lifecycle lifecycle, List<Fragment> fragmentList) {
        super(fragmentManager, lifecycle);
        this.fragmentList = fragmentList;
    }

    public MyFragmentPagerAdapter(FragmentActivity fm, List<Fragment> fragmentList) {
        super(fm);
        this.fragmentList=fragmentList;
    }

    @NonNull
    @Override
    public Fragment createFragment(int position) {
        return fragmentList.get(position);
    }

    @Override
    public int getItemCount() {
        return fragmentList.size();
    }

    @Override
    public long getItemId(int position) {
        return fragmentList.get(position).hashCode();
    }
}

MainActivity：

import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.viewpager2.widget.ViewPager2;

import com.google.android.material.tabs.TabLayout;
import com.google.android.material.tabs.TabLayoutMediator;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private final int[] tabIconView = {
            R.drawable.icon_home_nor,
            R.drawable.icon_meassage_nor,
            R.drawable.icon_selfinfo_nor,
            R.drawable.icon_square_nor,
            R.drawable.icon_more_nor
    };
    private final String[] tabTitles = {
            "首页",
            "消息",
            "好友",
            "广场",
            "更多"
    };
    private void addMyFragmentPagerAdapter() {
        List<Fragment> fragmentList = new ArrayList<>();

        Fragment1 fragment1 = new Fragment1();
        Fragment2 fragment2 = new Fragment2();
        Fragment3 fragment3 = new Fragment3();
        Fragment4 fragment4 = new Fragment4();
        Fragment5 fragment5 = new Fragment5();

        fragmentList.add(fragment1);
        fragmentList.add(fragment2);
        fragmentList.add(fragment3);
        fragmentList.add(fragment4);
        fragmentList.add(fragment5);

        MyFragmentPagerAdapter fragmentAdapter = new MyFragmentPagerAdapter(getSupportFragmentManager(),getLifecycle(), fragmentList);
        TabLayout tabLayout = findViewById(R.id.navigation);
        ViewPager2 viewPager = findViewById(R.id.view_pager);
        viewPager.setAdapter(fragmentAdapter);

        new TabLayoutMediator(tabLayout, viewPager,
                (tab, position) -> {
                    tab.setIcon(tabIconView[position]);
                    tab.setText(tabTitles[position]);
                }
        ).attach();
    }

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

布局文件：

<?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:id="@+id/father_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white">

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/maintab_toolbar_bg"
        android:layout_alignParentBottom="true"
        app:tabGravity="fill"
        app:tabIndicatorFullWidth="true"
        app:tabIndicatorGravity="top"
        app:tabIndicatorHeight="2dp"
        app:tabMode="fixed"
        app:tabRippleColor="#ADD8E6"
        app:tabUnboundedRipple="true"/>

</RelativeLayout>