Sample deferred CustomAction

fooaction.wxs

<?xml version="1.0" encoding="utf-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
  <Fragment>
    <Binary Id="Foo.dll" SourceFile="Foo.dll" />
    <CustomAction Id="CA_FooAction" BinaryKey="Foo.dll" DllEntry="CA_FooAction" Return="check" Execute="deferred" />
    <SetProperty Id="CA_FooAction" Before="CA_FooAction" Sequence="execute" Value="[FooProp]" />
    <InstallExecuteSequence>
      <Custom Action="CA_FooAction" After="InstallValidate" />
    </InstallExecuteSequence>
  </Fragment>
</Wix>

整形しなおし。。。