I am using the following attribute (as described here) to try and display a help file for my UDFs in excel:
[ExcelFunction(HelpTopic="MyHelp.chm!102")]
Unfortunately when I click the link "Help on this function" nothing is happening. If I make the reference invalid as follows:
[ExcelFunction(HelpTopic="MyHelpInvalid.chm!102")]
I get a popup from Excel saying "Help reference is not valid", and if I remove the tag I get a popup saying "No help available", so I know that this attribute is being read correctly.
My help file is in the same directory as my .xll file, and I am using MS Office 2010 (64 bit) on a windows 7 machine. The rest of the functionality in the addin works correctly. Can anyone help me find what id causing this problem?
Also, out of curiosity, does anyone know what the "!102" after the help file name means / does?
I think you have answered your own question. The 102 refers to the help TopicId. I presume you are seeing the error because that topic is is not defined in your help file.
You can read some more here: Determine topic id to open it in CHM file And maybe: How to get a list of topics from a chm file in C#