片段中的 Textview 显示背景颜色但不显示文本

Question

I have a piece of code that relies on android-fragments but I am facing an issue when the text in the textview does not show when I run the app in my phone while on android studio, it shows perfectly. My code is as follows:

MainActivity.java

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

    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    navigationView = (NavigationView) findViewById(R.id.nav_view);
    bottomNavigationView = (BottomNavigationView) findViewById(R.id.bottom_navigation);
    bottomNavigationView.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
    openFragment(HomeFragment.newInstance("", ""));
}

public void openFragment(Fragment fragment) {
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.container, fragment);
    transaction.addToBackStack(null);
    transaction.commit();
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?> 
<androidx.drawerlayout.widget.DrawerLayout
    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/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

  <include
     layout="@layout/app_bar_main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:id="@+id/includeTool"/>

  <FrameLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:id="@+id/container"/>

  <com.google.android.material.navigation.NavigationView
     android:id="@+id/nav_view"
     android:layout_width="wrap_content"
     android:layout_height="match_parent"
     android:layout_gravity="start"
     android:fitsSystemWindows="true"
     app:headerLayout="@layout/nav_header_main"
     app:menu="@menu/activity_main_drawer" />
</androidx.drawerlayout.widget.DrawerLayout>

fragment_home.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="wrap_content"
   tools:context=".fragments.HomeFragment">

   <View
      android:layout_width="match_parent"
      android:layout_height="?attr/actionBarSize"
      android:background="@color/bg_screen1"
      android:layout_alignParentTop="true"
      android:layout_alignParentStart="true"
      android:layout_alignParentLeft="true"
      android:id="@+id/view_container_top"
      android:visibility="invisible"/>

   <RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_below="@id/view_container_top"
      android:layout_above="@id/view_container_bottom">

     <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:src="@mipmap/ic_launcher"
        android:id="@+id/pic"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginLeft="8dp"
        android:contentDescription="TODO" />

     <TextView
        android:id="@+id/text_home"
        android:layout_below="@id/pic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="308dp"
        android:layout_marginEnd="8dp"
        android:gravity="center_horizontal"
        android:textAlignment="center"
        android:textSize="20sp"
        tools:text="home fragment" />
   </RelativeLayout>
   <View
      android:layout_width="match_parent"
      android:layout_height="?attr/actionBarSize"
      android:visibility="invisible"
      android:id="@+id/view_container_bottom"
      android:layout_alignParentBottom="true" />
</RelativeLayout>

Also below is a screenshot of how the app appears on the phone. As you can see from the screenshot the purple horizontal line in the middle of the screen is the textview background with no text on it.

Answer 1

Change:

tools:text="home fragment" 

To:

android:text"home fragment"

The tools tag is for Android Studio, the device won't see it

Answer 2

The problem is in TextView tag, replace the tools:text to android:text here:

<TextView
    android:id="@+id/text_home"
    android:layout_below="@id/pic"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="8dp"
    android:layout_marginTop="308dp"
    android:layout_marginEnd="8dp"
    android:gravity="center_horizontal"
    android:textAlignment="center"
    android:textSize="20sp"
    android:text="home fragment" />