title: WIX Toolset How to Set a Property
body: <p>This seems like it should be intuitive, but so far its been anything but.  How do I simply set a property I have defined in my product.wxs when my custom dialog first opens?  </p>
  
  <p>My Property is called "Port" which is initialized as blank.  I have another called "df_Port", which I set to "8080".  (These are set in my Product.wxs) When my Custom Dialog opens I want to set "Port" to "df_Port".  I also have an Edit control on the dialog whose "Property" setting is set to "Port". So obviously the User should be able to update Port, but if they hit the "Back" button, but eventually come back to this dialog, the default value of the Edit Control should go back to "8080"</p>
  
  <p>I have tried SetProperty, but it requires a Before or After property, and I have no clue on this.  I have also tried to create a CustomAction, but this hasn't worked either:</p>
  
  <pre><code>&lt;CustomAction Id="caPort" Property="Port" Value="[df_Port]"/&gt;
  </code></pre>
  
  <p>The control shows as blank, instead of "8080"</p>
  
  <p>I am using Wix 3.9 R2</p>