title: How to use multiselect in GridView with custom adapter?
body: <p>I have the <code>GridView</code> with <code>ImageView</code> and <code>TextView</code> in every cell. That worked fine and have no problems. But I need multichoice in this <code>GridView</code>. I want that the selected cells will be gray and unselected cells must be white. I've try to make selector with this code:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;selector xmlns:android="http://schemas.android.com/apk/res/android" &gt;
      &lt;item android:state_selected="false" android:drawable="@drawable/item_unselected" /&gt;
      &lt;item android:state_selected="true" android:drawable="@drawable/item_selected" /&gt;
  &lt;/selector&gt;
  </code></pre>
  
  <p>and set <code>android:choiceMode="multipleChoice"</code> in my <code>GridView</code>, but it doesn't work. How I can to do that?</p>