NSIS：使用带空格的绝对路径调用 DLL function

Question

I'm trying to call the function int MyFunction() from myfile.dll and to display it's return value in a message box.

What works so far:

  SetOutPath "$TEMP"
  File "myfile.dll"
  ;File "System.dll" for some time I thought one needs to copy the plugin, but that's not needed
  MessageBox MB_OK "$0"
  System::Call '$TEMP\myfile.dll::MyFunction()i.r0'
  MessageBox MB_OK "$0"
  System::Free 0

As soon as I replace $TEMP by $INSTDIR it doesn't work anymore. Actually it does, as long as $INSTDIR doesn't contain blanks, what C:\Program Files (x86) unfortunately does...

At one point I figured out from this NSIS forum post that this behavior is a bug, namely this one . I didn't really figure out what's the status of it.

I also tried the workaround with kernel32::LoadLibrary and kernel32::GetProcAddress that was presented in both pages, but I don't know what to use in the line System::Call "::$1(the usual parameters here)" .

So how do I call MyFunction() now?

Answer 1

The System plug-in supports quotes in the path now:

System::Call '"$InstDir\MyLibrary.dll"::MyFunction(i 42)'

Calling KERNEL32::AddDllDirectory is required if the DLL depends on other DLLs in the same directory but a single DLL should work without it.

When using kernel32::GetProcAddress the parameters are the same, it is only the path and function name that has changed to a direct address.

Answer 2

What fixed it in the end, was adding $INSTDIR to the search path, as suggested in this answer :

 System::Call 'KERNEL32::AddDllDirectory(w "$INSTDIR")'