title: MSBuild extract properties from one project to another
body: <p>Say I have two project files "Parent.proj" and "Child.proj".  If I declare a property in Parent.proj called <code>MyProp</code> I can pass this to Child.proj with the following code:</p>
  
  <pre><code>&lt;MSBuild Projects="Child.proj" Targets="dostuff" Properties="MyProp=MyValue" /&gt;
  </code></pre>
  
  <p>This is fine, but I want to know if there is a way of referencing <code>MyProp</code> within Child.proj without Child.proj being called by Parent.proj.</p>
  
  <p>I know I can declare the same property in Child.proj and this will get overriden when Child.proj is called by Parent.proj but I want to avoid repeating a property value.</p>