title: Delphi - How trigger a Windows Message from a Form and retrieve it in a component that is in that Form using Delphi?
body: <p>How trigger a Windows Message from a Form and retrieve it in a component that is in that Form using Delphi?</p>
  
  <p>Ex:</p>
  
  <p>In Form:</p>
  
  <pre><code>PostMessage(Handle, MY_MESSAGE, 0, 0);
  </code></pre>
  
  <p>In my Component (that is in same Form):</p>
  
  <pre><code>procedure OnMyMessage(var Msg: TMessage); message MY_MESSAGE;
  </code></pre>
  
  <p>in my case, OnMyMessage is simply not called!</p>
  
  <p><strong>The message is not only for this component, it is public, present on Form even if the component is not present. Thank you!</strong></p>