我想在捆绑层级上判断用户想要执行的操作是安装还是卸载。这是因为我的代码中还包含一个必须确保产品未被安装的 'Condition'。然而，'Uninstall'-操作必须始终能够进行。我也知道在这个层级上内置变量 'WixBundleAction' 不可用，但其实这正是我需要的（我想）。

有人知道怎么实现吗？

请看下方代码：

<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs"
     xmlns:bal="http://wixtoolset.org/schemas/v4/wxs/bal"
     xmlns:util="http://wixtoolset.org/schemas/v4/wxs/util">

  <Bundle UpgradeCode="{94447A2A-6CB4-42DE-942A-1500531F05A9}" 
          Name="Motor UI Software" 
          Manufacturer="Remuld B.V." 
          Version="$(var.BuildVersion)" 
          DisableModify="yes">

    <!-- Search for installation of TC.MotorUi.Files.msi (search for UpgradeCode) -->
    <util:ProductSearch UpgradeCode="{3B46D4C3-1EA9-63F2-A8FF-3DA48692CA43}"
                        Result="state"
                        Variable="EXISTING_FILES_STATE" />

    <!-- Only continue if productState is absent (2) OR during Uninstall, else exit with message. -->
    <bal:Condition Message="An existing installation was detected, setup cannot continue.&#13;&#10;Please uninstall existing version first!"
              Condition="EXISTING_FILES_STATE = 2 OR WixBundleAction = 3" /> <!-- WixBundleAction not available at this point -->

    <BootstrapperApplication>
      <bal:WixStandardBootstrapperApplication Theme="rtfRemMotr"
                                              LicenseFile="Resources\EULA.rtf"
                                              ThemeFile="Resources\Theme.xml"
                                              LocalizationFile="Resources\Theme.wxl"
                                              LogoFile="Resources\RemSideLogo.png"
                                              SuppressOptionsUI="yes" 
                                              SuppressRepair="yes" />
    </BootstrapperApplication>

    <Chain>
       ...
       ...
    </Chain>

  </Bundle>
</Wix>

解决方案

I'd try WixBundleInstalled, I think it's set early enough for wixstdba. Something like:

<!-- Only continue if already installed OR productState is absent (2). -->
<bal:Condition Message="An existing installation was detected, setup cannot continue.&#13;&#10;Please uninstall existing version first!"
               Condition="WixBundleInstalled OR EXISTING_FILES_STATE = 2" />

这在所有启动条件中都相当重要，这样用户在卸载时就不会被阻止。