android - hardcoded string "row three", should use @string resource

Question

I'm a beginner android developer , I was trying to run this Linear Layout in eclipse :

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

  <LinearLayout
      android:orientation="horizontal"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:layout_weight="1">
      <TextView
          android:text="red"
          android:gravity="center_horizontal"
          android:background="#aa0000"
          android:layout_width="wrap_content"
          android:layout_height="fill_parent"
          android:layout_weight="1"/>
      <TextView
          android:text="green"
          android:gravity="center_horizontal"
          android:background="#00aa00"
          android:layout_width="wrap_content"
          android:layout_height="fill_parent"
          android:layout_weight="1"/>
      <TextView
          android:text="blue"
          android:gravity="center_horizontal"
          android:background="#0000aa"
          android:layout_width="wrap_content"
          android:layout_height="fill_parent"
          android:layout_weight="1"/>
      <TextView
          android:text="yellow"
          android:gravity="center_horizontal"
          android:background="#aaaa00"
          android:layout_width="wrap_content"
          android:layout_height="fill_parent"
          android:layout_weight="1"/>
  </LinearLayout>

  <LinearLayout
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_weight="1">
    <TextView
        android:text="row one"
        android:textSize="15pt"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"/>
    <TextView
        android:text="row two"
        android:textSize="15pt"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"/>
    <TextView
        android:text="row three"
        android:textSize="15pt"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"/>
    <TextView
        android:text="row four"
        android:textSize="15pt"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"/>
  </LinearLayout>

</LinearLayout>

And, I noticed :
1) yellow line under android:text="Yellow"
2) yellow line under android:text="row four"
the Triangle warn says [I18N] Hardcoded string "Yellow", should use @string resource " and same for the rest of the warnings.Any suggestion?

Answer 1

It is not good practice to hard code strings into your layout files. You should add them to a string resource file and then reference them from your layout.

This allows you to update every occurrence of the word "Yellow" in all layouts at the same time by just editing your strings.xml file.

It is also extremely useful for supporting multiple languages as a separate strings.xml file can be used for each supported language.

example: XML file saved at res/values/strings.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="yellow">Yellow</string>
</resources>

This layout XML applies a string to a View:

<TextView android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:text="@string/yellow" />

Similarly colors should be stored in colors.xml and then referenced by using @color/color_name

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="Black">#000000</color>
</resources>