How to use DllCall with a function that returns a tuple

[ozymandius257]

I have a DLL which returns a tuple value (boolean, string).

I tried using the following:

$Result = DllCall("mydll.dll", "BOOLEAN:STR", "Check_if_running")

but I get back @error = 2 (unknown return type)

If I change the return type to just BOOLEAN, I then get @error = 3 (function not found in the DLL)

I'm trying to do this as I have written a program using the DLL in VB.Net, but I'm wondering if the same program in AutoIt would produce an exe which would have a smaller memory usage, as the program has to run 24 hours a day on machines with limited memory.

 

 

[Danp2]

I'm guessing that you would need to use type STRUCT. See the 3rd example for DllCall in the help file.

[Danyfirex]

Hello, show your dll function declaration information.

 

Saludos

[ozymandius257]

Hi, sorry for the long delay - been away.

 

Anyway, still no success, so I wrote a simple function in my dll which just returns a string, but I'm still getting @error returned as 3 - "function not found in the DLL file".

I know the function is there, as I wrote the DLL in VB.net, so here's my autoit code...

Local $Returned = DllCall("c:\mydll.dll", "STR", "Test", "STR", "Test")
if @error <> 0 Then
    MsgBox(0, "Error", @error)
Else
    MsgBox (0, "", $Returned[0])
EndIf

And the dll function is this:

Public Function Test(strInput As String) As String

        Return "The input string was " & strInput

    End Function

The only thing I can think of is that the function is in a class inside the DLL, so if the class is called 'TestFunctions', how would I pass that in the DLLCall? - I've tried 

DllCall("c:\mydll.dll", "STR", "TestFunctions/Test", "STR", "Test")

DllCall("c:\mydll.dll", "STR", "TestFunctions\Test", "STR", "Test") 

DllCall("c:\mydll.dll", "STR", "TestFunctions:Test", "STR", "Test")

DllCall("c:\mydll.dll", "STR", "TestFunctions.Test", "STR", "Test") with no joy 😕

 

[Danp2]

2 hours ago, ozymandius257 said:

I know the function is there, as I wrote the DLL in VB.net

See this post for an explanation of why the function can't be found.