TabLayout使用自定义的图文布局，每个Tab设置不同的背景

效果

特点：
1、TabLayout使用setCustomView 实现带图标的tab；
2、每个Tab设置不同的背景；

1、页面布局：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"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:background="@color/cl_f4f1f4">

       <android.support.design.widget.TabLayout
           android:id="@+id/tablayout"
           android:layout_width="match_parent"
           android:layout_height="48dp"
           android:layout_marginStart="16dp"
           android:layout_marginTop="12dp"
           android:layout_marginEnd="16dp"
           android:layout_below="@id/cl_check_statistic"
           app:tabRippleColor="@color/bg_transparent"
           app:tabIndicatorHeight="0dp" />

       <View
           android:id="@+id/divider_line"
           android:layout_width="match_parent"
           android:layout_height="0.33dp"
           android:layout_below="@id/tablayout"
           android:layout_marginStart="16dp"
           android:layout_marginEnd="16dp"
           android:background="@color/cl_ccc" />

       <android.support.v4.view.ViewPager
           android:id="@+id/viewpager"
           android:layout_width="match_parent"
           android:layout_height="match_parent"
           android:layout_below="@id/divider_line"
           android:layout_marginStart="16dp"
           android:layout_marginEnd="16dp" />
   </RelativeLayout>

2、自定义Tab布局（左图右文字）：icon_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:layout_gravity="center"
    android:gravity="center"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/tabicon"
        android:layout_width="15dp"
        android:layout_height="15dp" />

    <TextView
        android:id="@+id/tabtext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="3dp"
        android:textColor="@color/cl_666"
        android:textSize="14sp"
        tools:text="@string/preview_text" />
</LinearLayout>

3、详细代码：

• getTabView()使用自定义布局；
• setTabBackground()设置不同背景；

@ContentView(R.layout.activity_main)
@ViewModel(MainViewModel.class)
public class MainActivity extends BaseActivity<ActivityMainBinding, MainViewModel>{
    private List<Fragment> myFragment;
    private String[] titleArr = {"待完成", "待提交", "主动检查"};
    private int[] selectedArr = {R.mipmap.icon_pending_selected, R.mipmap.icon_uncommit_selected, R.mipmap.icon_initiative_check_selected};
    private int[] unSelectedArr = {R.mipmap.icon_pending_unselected, R.mipmap.icon_uncommit_unselected, R.mipmap.icon_initiative_check_unselected};
    private final int DEFAULT_POSITION = 0;

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

    /**
     * 导航栏布局：https://blog.csdn.net/xiaoshuxgh/article/details/80389570
     */
    private void initLayout() {
        myFragment = new ArrayList<>();
        myFragment.add(new PendingFragment());
        myFragment.add(new UnCommitFragment());
        myFragment.add(new InitiativeCheckFragment());

        mBinding.viewpager.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager()) {
            @Override
            public Fragment getItem(int i) {
                return myFragment.get(i);
            }

            @Override
            public int getCount() {
                return myFragment.size();
            }

            @Nullable
            @Override
            public CharSequence getPageTitle(int position) {
                return titleArr[position];
            }
        });

        mBinding.tablayout.setupWithViewPager(mBinding.viewpager);

        // 注意：这个方法需要放在setupWithViewPager()后面
        for (int i = 0; i < mBinding.tablayout.getTabCount(); i++) {
            TabLayout.Tab tabView = mBinding.tablayout.getTabAt(i);
            tabView.setCustomView(getTabView(i));
            setTabBackground(tabView, false);
        }

        mBinding.tablayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                //设置选中图标样式
                View tabView = tab.getCustomView();
                tabView.findViewById(R.id.tabicon).setBackgroundResource(selectedArr[tab.getPosition()]);

                //设置选中字体颜色
                TextView textView = tabView.findViewById(R.id.tabtext);
                textView.setTextColor(getResources().getColor(R.color.theme_color));
                setTabBackground(tab, true);
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {
                //设置未选中图标样式
                View tabView = tab.getCustomView();
                tabView.findViewById(R.id.tabicon).setBackgroundResource(unSelectedArr[tab.getPosition()]);

                //设置未选中字体颜色
                TextView textView = tabView.findViewById(R.id.tabtext);
                textView.setTextColor(getResources().getColor(R.color.cl_666));
                setTabBackground(tab, false);
            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {
            }
        });

        setTabBackground(mBinding.tablayout.getTabAt(DEFAULT_POSITION), true);
    }

    /**
     * 使用自定义的View布局
     *
     * @param position
     * @return
     */
    private View getTabView(int position) {
        View v = LayoutInflater.from(mActivity).inflate(R.layout.icon_view, null);
        ImageView iv = v.findViewById(R.id.tabicon);
        TextView tv = v.findViewById(R.id.tabtext);

        tv.setText(titleArr[position]);
        //设置默认页面
        if (position == DEFAULT_POSITION) {
            iv.setBackgroundResource(selectedArr[position]);
            tv.setTextColor(v.getResources().getColor(R.color.theme_color));
        } else {
            iv.setBackgroundResource(unSelectedArr[position]);
            tv.setTextColor(v.getResources().getColor(R.color.cl_666));
        }
        return v;
    }

    /**
     * TabLayout每个Tab选中背景不一样。
     * https://blog.csdn.net/qq_32606467/article/details/103068611
     *
     * @param tab
     * @param selected
     */
    private void setTabBackground(TabLayout.Tab tab, boolean selected) {
        Drawable drawable = null;
        switch (tab.getPosition()) {
            case 0:
                if (selected) {
                    drawable = mActivity.getDrawable(R.drawable.tab_background_selected_0);
                } else {
                    drawable = mActivity.getDrawable(R.drawable.tab_background_unselected_0);
                }
                break;
            case 1:
                if (selected) {
                    drawable = mActivity.getDrawable(R.drawable.tab_background_selected_1);
                } else {
                    drawable = mActivity.getDrawable(R.drawable.tab_background_unselected_1);
                }
                break;
            case 2:
                if (selected) {
                    drawable = mActivity.getDrawable(R.drawable.tab_background_selected_2);
                } else {
                    drawable = mActivity.getDrawable(R.drawable.tab_background_unselected_2);
                }
                break;
        }

        ViewCompat.setBackground(tab.view, drawable);
    }
}