似乎我需要暂停托管代码，以便该过程出现在调试窗口中.可以通过调用MessageBox.Show来完成.之后，msiexec托管代码条目将出现在流程中，如果我附加了该条目，则将能够调试自定义操作代码.

It appears that I need to halt my managed code so the process will appear in the debug window. It can be done by calling MessageBox.Show. After that the msiexec managed code entry appears in the processes and if I attach to it I will be able to debug my custom actions code.