freeing up CoCreateObjectDotNet or removing reference

[remondo]

Hi,

I am calling a .Net function inside a dll that is unpacked into the SUPPORTDIR folder.

I noticed that if CoCreateObjectDotNet() is called, that dll would not be deleted from SUPPORTDIR after installation ends.

Then, if I purposely don't call CoCreateObjectDotNet(), that dll is automatically deleted FROM SUPPORTDIR after installation. Which leads me to suspect that I might not be freeing up the object correctly. Here is my code below.

The documentation also mentions to use CoFreeLibrary(), however, I cannot use it as it's causing Build errors.

set oLib=CoCreateObjectDotNet(szDLLpath,"DllName.ClassName");
ret = oLib.MyMethod(param);

set oLib= NOTHING; // this is not enough apparently.

Looking forward to an answer for this issue.

Thank you!

[Jenifer · Accepted solution]

Hi @remondo ,

I could see "CoCreateObjectDotNet" function is deprecated in IS2014 onwards,how about using "DotNetCoCreateObject"?

https://helpnet.flexerasoftware.com/installshield21helplib/Subsystems/installshield21langref/helplibrary/CoCreateObjectDotNet.htm?

https://helpnet.flexerasoftware.com/installshield21helplib/Subsystems/installshield21langref/helplibrary/DotNetCoCreateObject.htm#langref_appendixa_3241381926_1156948

What are the build error you get on using  CoFreeLibrary()?

Thanks,

Jenifer

[remondo]

Thank you for your reply Jennifer! You have pointed me to the right direction.

I am using Installshield 2016.

1. Regarding CoFreeLibrary(), it's my mistake, I forgot to declare the prototype

prototype void ole32.CoFreeLibrary( byval int );

In order to call CoFreeLibrary(), I need to get the handle to the dll.

So I needed to call GetModuleHandle() first to get the handle. It didn't work.

2. I also tried the UseDLL() and UnUseDLL();

Didn't work.

Caveat: UnUseDLL()'s parameter according to the documentation should not include the path.

UseDLL() needs the path though.

3. DotNetCoCreateObject()

So I had to specify a temporary app domain name, then call DotNetUnloadAppDomain() afterwards.

This worked! 

set oLib=DotNetCoCreateObject(szDLLpath,"MyDLLName.MyClassName", "tempdomain");

retDotNet = oLib.MyCSharpMethod();

retDotNet = DotNetUnloadAppDomain("tempdomain"); // returns 0