主页面ui

<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=".ui.activity.MainActivity">

    <FrameLayout
        android:id="@+id/main_page_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginBottom="49dp"
        android:background="#EFEEEE"
        />

    <!--    导航-->
    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/main_navigation_bar"
        android:layout_width="match_parent"
        android:layout_height="49dp"
        android:layout_alignParentBottom="true"
        android:background="@color/white"
        app:labelVisibilityMode="selected"
        app:menu="@menu/moudulemain_my_navigation_items"
        tools:ignore="MissingConstraints" />


</RelativeLayout>

切换方式

    private BaseFragment lastOneFragment = null;

    private void switchFragment(BaseFragment targetFragment) {
        //如果上一个Fragment和当前要切换的fragment是同一个，那么不需要切换
        if (lastOneFragment == targetFragment){
            return;
        }
        //修改成add和hide的方式来控制Fragment
        FragmentTransaction fragmentTransaction = mFm.beginTransaction();
        //如果没有添加就添加
        if (!targetFragment.isAdded()) {
            fragmentTransaction.add(R.id.main_page_container,targetFragment);
        }else {
            fragmentTransaction.show(targetFragment);
        }
        if (lastOneFragment!=null){
            fragmentTransaction.hide(lastOneFragment);
        }
        fragmentTransaction.commit();
        lastOneFragment = targetFragment;

    }

不能切换页面

图中fragment并不会显示其他页面