How do I pass msiexec properties to a Wix C# custom action

I have an MSI being created with Wxs 3.0. My MSI references a C# custom action, written using the new C# Custom Action project (http://blogs.msdn.com/jasongin/archive/2008/05/23/custom-action-project-templates.aspx)

I want to pass an argument to msiexec that gets routed to my custom action - eg:

msiexec /i MyApp.msi ENVIRONMENT=TEST#

In my Wxs, I refer to my custom action like this:

<Property Id="ENVIRONMENT"/>
<Binary Id="WixCustomAction.dll"  SourceFile="$(var.WixCustomAction.Path)" />
<CustomAction Id="WixCustomAction" BinaryKey="WixCustomAction.dll"    DllEntry="ConfigureSettings"/>
<InstallExecuteSequence>
   <Custom Action="WixCustomAction" After="InstallFiles"></Custom>
</InstallExecuteSequence>

My C# custom action is setup like this:

[CustomAction]
public static ActionResult ConfigureSettings(Session session)
{

}

I was expecting to be able to access the property like this:

string environmentName = session.Property["ENVIRONMENT"];

but this doesn't seem to work.

How do I access the propery I passed to msiexec in my custom action?

From stackoverflow

• Your CA needs to be a deferred CA in order to run after InstallFiles. Deferred CA's do not have access to properties, but they do have access to CustomActionData. See this blog post for a discussion on how to get what to do about it. (this example is a VBScript CA, but you will be able to retrieve the value through the session.CustomActionData collection)

• Just for completeness; utilising the method described by Jeremy Lew, in the blog above allows for the following:

  Calling:

  msiexec /i ITP.Platform.2.msi ENVIRONMENT=QA CONFIGFILE=EnvironmentConfig.xml
  

  With this in the Wxs:

  <Property Id="ENVIRONMENT" Secure="yes" />
  <Property Id="CONFIGFILE" Secure="yes" />
  <Binary Id="Itp.Configurator.WixCustomAction.dll" SourceFile="$(var.Itp.Configurator.WixCustomAction.Path)" />
   <CustomAction Id="SetCustomActionDataValue" Return="check" 
        Property="Itp.Configurator.WixCustomAction" Value="[ENVIRONMENT],G2,[CONFIGFILE],[TARGETDIR]ITP_v$(var.VERSION_MAJOR)" />  
  
  <CustomAction Id="Itp.Configurator.WixCustomAction" Return="check" Execute="deferred"
        BinaryKey="Itp.Configurator.WixCustomAction.dll" DllEntry="ConfigureItpBrandSettings" />
   <InstallExecuteSequence>
     <Custom Action="SetCustomActionDataValue" After="InstallFiles"></Custom>
     <Custom Action="Itp.Configurator.WixCustomAction" After="SetCustomActionDataValue"></Custom>
   </InstallExecuteSequence>
  

  With custom action:

      /// <summary>
      /// CustomAction keys should be Environment,BrandId,ConfigPath,itpBasePath
      /// </summary>
      /// <param name="session"></param>
      /// <returns></returns>
      [CustomAction]
      public static ActionResult ConfigureItpBrandSettings(Session session)
      {
          string[] arguments = GetCustomActionDataArguments(session);
  
          string environmentName = arguments[0];
          string brandId = arguments[1];
          string configPath = arguments[2];
          string itpBasePath = arguments[3];
  
    //Do stuff
  
          return ActionResult.Success;
      }
  
      private static string[] GetCustomActionDataArguments(Session session)
      {
          string[] keys = new string[session.CustomActionData.Keys.Count];
          session.CustomActionData.Keys.CopyTo(keys,0);
          return keys[0].Split(',');
      }
  

  works.

  Parsing the CustomActionData arguments is pretty ugly, but it does work. - hopefully someone knows a more elegant way to do this.

• If instead of

  <CustomAction Id="SetCustomActionDataValue" Return="check" Property="Itp.Configurator.WixCustomAction" Value="[ENVIRONMENT],G2,[CONFIGFILE],[TARGETDIR]ITP_v$(var.VERSION_MAJOR)" />
  

  you write this:

  <CustomAction Id="SetCustomActionDataValue" Return="check" Property="Itp.Configurator.WixCustomAction" Value="Environment=[ENVIRONMENT];G=G2;ConfigFile=[CONFIGFILE];TargetDir=[TARGETDIR]ITP_v$(var.VERSION_MAJOR)" />
  

  then you will be able to reference your variables like this:

  string env=session.CustomActionData["Environment"];