InnoSetup：用于在文件/文件夹存在时取消设置的Pascal脚本

Question

In my InnoSetup I use several file actions in the InstallRun section. If those are executed correctly without problems then a certain temp folder should have been deleted.

If something has gone wrong then the temp folder is still there. In that case I want the setup to be canceled with a messagebox displaying an error message of my choice.

As I have no experience (yet) with Pascal script I kindly ask you to provide me with an example script yo do this.

Thanks in advance!

Addition: I'll now explain the reason I need this. The scenario is updating an existing version, which is a Windows Service application. Before updating those files I have to uninstall the services first. For this I use my own commandline that's in the installation package. The other new files will be temporary unpacked to a temp folder (subfolder of app folder). After the Windows services are uninstalled the new files are moved from the temp folder to the app folder. If something goes wrong here I want to cancel the setup and show an error message to the user. I can best tell if something has gone wrong by checking if the temp folder is still there.

Answer 1

Assuming that you mean the [Run] section, it is not possible to cancel the installation that late in the process.

Instead, you should look at using PrepareToInstall . In this, all you need to do is to stop and deregister the old service, either directly via API or by invoking a command on the old service EXE as you choose. (Don't forget to handle the case when the service doesn't exist yet, for new installs.)

After this [Files] will replace the files as normal and you can then [Run] or use code (via AfterInstall or CurStepChanged(ssPostInstall) , depending on the time you want it to happen) to re-register and start the service.

No need to muck around with temporary folders -- which is good, because that would have caused problems for uninstall as well.