title: ComboBox transparency issue how to prevent it, in wp8.1 C#
body: <p>When i opened comboBox with 4 items, It is working properly but it is showing if it has any controls behind of comboBox when it open ,those controls also visible.How to prevent and i didn't add any background color</p>
  
  <p><a href="http://i.stack.imgur.com/eE6Fr.png" rel="nofollow">ComboBox before opening image</a></p>
  
  <p><a href="http://i.stack.imgur.com/xy45b.png" rel="nofollow">ComboBox After opening image</a></p>
  
  <pre><code>&lt;ComboBox x:Name="cmbBoxPriority" Margin="157,323,17,372" Tapped="cmbBoxPriority_Tapped" Opacity="1" Background="#FFD8CFCF"   Foreground="Black"  &gt;
                      &lt;x:String&gt;Low&lt;/x:String&gt;
                      &lt;x:String&gt;Medium&lt;/x:String&gt;
                      &lt;x:String&gt;High&lt;/x:String&gt;
                      &lt;x:String&gt;Critical&lt;/x:String&gt;
                  &lt;/ComboBox&gt;
  </code></pre>