Digital Workshop

I am trying to use an external DLL function from a 3rd party supplier but am not sure what Value type to use.

Both the return value and the parameters to be set are specified by the DLL supplier as being string, boolean or integer.

String is OK
If I read the manual correctly the boolean is entered with no type or quotes
Which value type do I use for an integer?


The function being called has 7 parameters and returns an integer

file=string
key=string
moduleID=string
name=String
User=Boolean
Quit=Boolean
Tag=String


A sample line of java code looks like this:

mytest res = testfunction(location, readKey, "QHD001", "", true, false, tag);


Here is my interpretation within Opus. The DLL loads fine, its the function call that gives a NULL result.

var MyDLL = LoadDLL( SYSTEM_PUBLICATION_DIR + "mytest.dll" );

readkey="abc123"
location=SYSTEM_PUBLICATION_DIR+"demofile.fil"


if (MyDLL)
{
test_return = MyDLL.CallFn("testfunction",false,"sshort","string",location,"string",readkey,"string","DQH001","none","",false,false,"string","tagvar");


Debug.trace(test_return); // this gives a NULL return


If I break this down this is what I think I am requesting:

test_return = MyDLL.CallFn // call the function from MyDLL
("testfunction", //the function is called testfunction
false, // there is no screen element
"sshort", //The return value will be of the type sshort
"string",location, // location is a string held in a variable
"string",readkey, //readkey is a string held in a variable
"string","DQH001", //DQH001 is a string
"none","", // this value is not required and is null
false, // this value is boolean false
false, // this value is boolena false
"string","tagvar"); //this value is text

Can anyone help me make sense of this?????

first, have a look at
viewtopic.php?t=2756&highlight=unmanaged and viewtopic.php?t=2674&highlight=unmanaged

If the DLL was created in a managed environment such as visual 'something' it probably won't work in Opus. Opus needs DLLs created in native WIN32 applications such as PowerBasic, Delphi, and standard C++ environments which produce unmanaged code.

I have seen a DLL load successfully but not run.

In your DLL call, I think the false should be within quotes "false"


also try "none" in place of the last two false types




Can you attach the DLL to have a try with it?? I find the best way to solve a problem like this is just to hack it---you can apply logic, but when that doesn't work, it comes down to trying all the combinations.
For integer values, I use the 'ULONG' type, so try that in place of the sshort.



Are you sure there are no syntax errors in your script, for example there is a curly missing in the DLL call, but I assume it's the way you cut and paste, you would normally get an error, but not always.

Hi 1Vision,

Sandyn is right about reviewing the other posts. He pointed me in the right direction originally and after much (and I mean much) hard work I've developed a decent undertsanding of both DLLs and using them in Opus.

One big must is to download the DLL Export Viewer - from http://www.nirsoft.net/utils/dll_export_viewer.html

If you can't see the function calls in that, then they are not available in Opus even if the DLL does load. If the FCs are there, then as Sandyn says, you can normally 'hack' together the correct code to get the information to / from the DLL.

Mack

Without having the exact details, I would suggest something like this:

Did your supplier give you a header file or other documentation of the exact types the function uses?