Please help understanding some code

[Chrissirhc]

Hi,

Could someone explain the VBA code below (Its using a windows API)

If RegOpenKeyA(MyKey, Path, hKey) <> 0 Then
y = regCreateKeyA(MyKey, Path, hKey)
End If

Thanks,

Chris

 

[rjoubert]

RegOpenKeyA attempts to open a Registry key. If it is successful, it will return a value of 0. If it doesn't find the Registry key passed in, the return value will not be 0. The If statement checks for the return value...if it is not equal to 0, it didn't find the Registry key, so it uses the RegCreateKeyA to create the Registry key.

Info on RegOpenKeyA:

http://source.winehq.org/WineAPI/RegOpenKeyA.html

Info on RegCreateKeyA:

http://source.winehq.org/WineAPI/RegCreateKeyA.html

 

[Chrissirhc]

How comes when I delete the reg key in question. The function still returns 0?

I can't seem to get the if statement to return false at the moment.

Thanks,

Chris

 

[rjoubert]

Check out the example in this link. I would suggest modifying your code to make the call to RegOpenKeyA like the call to RegOpenKey in the example.

http://www.sysdeco.no/Doc/Langref/regopenkey.htm

 

[Chrissirhc]

Thanks. Regarding the code I posted (I just wanted to understand what the author was thinking) Do you have any ideas? I mean in practice if the key is not there it still returns 0...

It may be academic, but do you have any ideas?

Thanks a lot,

Chris

 

[rjoubert]

The If statement you posted is checking for an error code, or a non-zero return value. If it returns a zero, then no error occured, in theory.

 

[Chrissirhc]

Hmm so in practice not finding a key in the registry is not an error?

 

[Chrissirhc]

Has anyone had this experience with this reg key?

 

[TonyJollans]

Has anyone had this experience with this reg key?

What reg key?

From your other thread I know this is related to code from a book that you can't post here and as I don't have the book I can't really help much.

I am not aware of any issues with this API; if it returns success it has had success. Are you absolutely sure you are trying to open the key you think you are and that it doesn't exist? If you use the handle from the Open to read a value (which you say doesn't exist), what do you get?

Enjoy,
Tony

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