WIX dynamically set install path according to registry key

I am using WIX to generate an MSI to install an application. I want the application to be installed in a subfolder of a previously installed application. The issue is that the path for this previously installed application can be changed at install time (the UI provides a directory selection dialog); the path is however saved in a registry key. How can I get the value 开发者_开发知识库of this registry key and use it as TARGETDIR value for my new application?

I'd use a ComponentSearch and set the result in TARGETDIR using a custom action.

You should take a look at the RegistrySearch element. And by the way, this paragraph of the WiX tutorial describes the approach you should follow in such situations.

Hope this helps.