title: Android:layout_toLeftOf ~ No resource found
body: <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;merge xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;TextView
          android:id="@+id/pickerDialog_title"
          android:layout_width="100dp"
          android:layout_height="wrap_content"
          android:gravity="left|center_horizontal"
          android:text="HELLO WORLD!!" /&gt;
      &lt;NumberPicker
          android:id="@+id/pickerDialog_selector"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@id/pickerDialog_title" /&gt;
      &lt;Button
          android:id="@+id/pickerDialog_cancel"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@id/pickerDialog_selector"
          android:layout_toLeftOf="@id/pickerDialog_set" //Cannot find @id/pickerDialog_set
          android:gravity="center"
          android:text="Cancel" /&gt;
      &lt;Button
          android:id="@+id/pickerDialog_set" //Here it is
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@id/pickerDialog_selector"
          android:layout_toRightOf="@id/pickerDialog_cancel"
          android:gravity="center"
          android:text="Set" /&gt;
  &lt;/merge&gt; 
  </code></pre>
  
  <p><code>No resource found that matches the given name (at layout_toLeftOf with value @id/pickerDialog_set</code></p>
  
  <p>It was my understanding that, <code>android:id</code> should be prefixed as <code>@+id/</code>, with reference made to the view to be prefixed as <code>@id/</code></p>
  
  <p><b>How do i reference ids correctly?</b></p>