Library Function Error

[Paco]

Hello,

i have written a program in LabWindow/CVI 6.0 that is using a serial COM-Port and the WindowsMediaPlayer by ActiveX. The part using the WMP allready worked, afterwards i wrote also the part of the program using serial Port. Since i have written the part for the serial Port the WMP part doesn't work anymore because of a library function error.

Used Libs:

     #include <cvirte.h>
     #include "wmp.h"
     #include <utility.h>
     #include <userint.h>
     #include <rs232.h>
     #include "asynctmr.h"

Code:

     int SoundFiles = SndFiPanel_SelectedSoundFiles; (SelectedSoundFiles is a Listbox on the Panel SndFiPanel)

     ClearListCtrl (SndFiPanel, SoundFiles);                                //The Run-Time Error comes by this function call

Error Message:

     NON-Fatale Run-Time Error

     Library function Error (return value == -60)

     Control passed must be a list control.

Has somebody an idea what the problem is?

Greetings Paco

[RobertoBozzolo]

The most probable cause of this error is an incorrect value used as the panel handle in ClearListCtrl ().

Since the list control is named SndFiPanel_SelectedSoundFiles, it means that SelectedSoundFiles is the constant name of the list control on the panel while SndFiPanel is the constant name with which you have called the panel in the UIR editor. This is NOT the panel handle with which to address the panel and its controls: the panel handle is the value returned by LoadPanel () function.

That is, your code is to be modified as follows:

handle = LoadPanel (0, "file.uir", SndFiPanel);    // Made elsewere in the program

int SoundFiles = SndFiPanel_SelectedSoundFiles;   //SelectedSoundFiles is a Listbox on the Panel SndFiPanel

ClearListCtrl (handle, SoundFiles);                                //The Run-Time Error comes by this function call

It may have happened that the panel handle had the same value as its constant name, but it is to be considered as a mere coincidence. It may have happened that adding the portion of code which is in charge of the serial communication you have altered this coincidence loading another panel before that of the sound part of the application or something like this, getting the error due to the incorrect value used as the panel handle.

[Paco]

Thanks for helping me. The program is working now.

Greetings Paco