title: Android "string error" while developing for Android API 19?
body: <p>So, I'm developing with Android. I'd like to know, what is wrong with this code? On <strong>activity_main.xml</strong> in the <strong>res/layout</strong> directory, in the Graphical Layout editor, it gives me this error:</p>
  
  <pre><code> Couldn't resolve resource @string/edit_message
   Couldn't resolve resource @string/button_send
  </code></pre>
  
  <p>Strings:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;resources&gt;
    &lt;string name="app_name"&gt;My First App&lt;/string&gt;
    &lt;string name="edit_message"&gt;Enter a message&lt;/string&gt;
    &lt;string name="button_send"&gt;Send&lt;/string&gt;
    &lt;string name="action_settings"&gt;Settings&lt;/string&gt;
    &lt;string name="title_activity_main"&gt;MainActivity&lt;/string&gt;
  &lt;/resources&gt;
  </code></pre>
  
  <p>Layout:</p>
  
  <pre><code>&lt;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:orientation="horizontal"&gt;
      &lt;EditText android:id="@+id/edit_message"
          android:layout_weight="1"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:hint="@string/edit_message" /&gt;
      &lt;Button
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/button_send" /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>