title: How to check property value in a WCF activity?
body: <p>I am really new to windows workflow and I need to create an activity. I did that:</p>
  
  <pre><code>class CustomActivity : Activity { }
  </code></pre>
  
  <p>This activity has custom a property and I did that:</p>
  
  <pre><code>class CustomActivity : Activity 
  {
      /// &lt;summary&gt;
      /// Creation of the Value Property.
      /// &lt;/summary&gt;
      [Description("The value of the property to set")]
      [Category("Configuration")]
      [Browsable(true)]
      [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
      public string Value { get; set; }
  }
  </code></pre>
  
  <p>Now I would like to check what the user set in this property when he uses the designer. For example, if he compiles the workflow, is there any callback when the workflow is compiled, so I could generate compilation error ? Or any integrity check callback ?</p>
  
  <p>Thanks for you help.</p>