所有Visual Studio定制操作都在安装了所有文件之后运行，因此在安装主输出之前，您不能使用定制操作来安装另一个MSI.另外，由于不允许同时进行基于MSI的安装，因此通过自定义操作运行基于MSI的安装可能会失败.

All Visual Studio custom actions run after all the files have been installed, so you cannot use a custom action to install another MSI before your primary output is installed. Also, running an MSI-based install from a custom action is likely to fail because concurrent MSI-based installs are not allowed.

执行此操作的通常方法是创建一个引导程序包，该程序包会在安装MSI之前先安装依赖项，然后从这里开始:

The normal way to do this is to create a bootstrapper package that installs dependencies before your MSI is installed, start here:

https://msdn.microsoft.com/en-us/library/ms165429.aspx