title: Anyway to create a custom MSBuild property in WIX wxs file?
body: <p>My target is to auto-name the output msi file with version number in WIX 3.6 project. I find this link:
  <a href="http://blog.tentaclesoftware.com/archive/2010/08/05/99.aspx" rel="nofollow">Automated installer version numbers for WiX, revisited</a> but we have a slightly different scenario: we don't want to control our product version number by referencing to any assembly's version number. Instead, we just simply want to assign it in wix files. Specifically, I have a wxi file which defines a property like this:</p>
  
  <pre><code>&lt;?define VersionNumber = "1.1.2000" ?&gt;  
  </code></pre>
  
  <p>As a result, I can use this VersionNumber variable anywhere inside our Product.wxs file. But since the easiest way to rename the output msi file seems to be adding a postbuild task in MSBuild, I must pass this VersionNumber out to the MSBuild project file. This is what stops me.</p>
  
  <p>I tried the other way around, i.e., to define the VersionNumber constant in the MSBuild and use it inside WIX. It works fine except I must keep this constant the same for different Build/Platform combinations. We are building our software in VS IDE which means if we modify the version number in IDE's window, it would only apply to the specific Build/Platform combination and the other combinations will remain unchanged(I know if I am building from command line I can simply pass a version number to overwrite the existing one). And that is what I don't want to see. I like the idea to only define the version number in one place to avoid any possible mistake. </p>
  
  <p>Any help will be appreciated!</p>