Wix: Create File in Custom Action DLL

Question

I have a problem with WiX and C++ custom actions DLL: In my custom action I create a file and when I debug it, I got an access denied.

WiX file:

<CustomAction Id="ChangeConfig"
              BinaryKey="PcmConfig"
              DllEntry="ModifyConfigFile"
              Execute="immediate"
              Return="check"
              HideTarget="no" />

<InstallExecuteSequence>
  <Custom Action="ChangeConfig" Before="InstallFinalize" />
</InstallExecuteSequence>

Custom Action method:

HANDLE hFile = CreateFile(L"c:\Temp.txt", // name of the write
                          GENERIC_WRITE,
                          0,
                          NULL,
                          CREATE_NEW,
                          FILE_ATTRIBUTE_NORMAL,
                          NULL);

I saw some people suggested to change to run as deferred and Impersonate attribute set to "no", it seems it didn't call the custom action function at all.

Anyone a idea? Thanks in advance!

Answer 1

Have you tried adding a extra slash to make it "C:\\\\Temp.txt" or did the stackoverflow formatting remove it from your pasted code? If that doesn't work, try creating a C:\\Temp\\ folder as I've seen some OS's (or group policies) protect that root folder from having new files created (but allowed files to be copied into it), while sub-folders were allowed to create a new file.

HANDLE hFile = CreateFile(L"c:\\Temp.txt", // name of the write
                      GENERIC_WRITE,
                      0,
                      NULL,
                      CREATE_NEW,
                      FILE_ATTRIBUTE_NORMAL,
                      NULL);