Visual Basic, I need help from a vb and vc++ expert

I need help from a vb and vc++ expert

Author	Message
hain2.. #1 / 8	I need help from a vb and vc++ expert Jonathan, If the parametars are passed correctly, I would guess GFP is caused by the function itself. Here is a small basic sample. From VC++: extern "C" BOOL Pascal EXPORT ExportedFunction(int i,char* szTest) { char szChr[10]; itoa(i,szChr,10); AfxMessageBox(szChr); AfxMessageBox(szTest); return TRUE; Quote: } In DEF file: EXPORTS ; Explicit exports can go here Calling From VB: Declare Function ExportedFunction Lib "yourdll" (ByVal i As Integer, ByVal szChar As String) As Boolean Private Sub Command5_Click() Dim bRetval As Boolean bRetval = ExportedFunction(100, "Made it - Have Fun") End Sub Run your VC++ app in debug mode with breakpoints and check out passing parameters from your VB app. I do it all the time. HTH Quote: > I am having trouble getting vb to call my vc++ dll. Everytime I run my > demo, > I get a GPF. The Visual C++ demo program I wrote works fine. If there is > anyone > out there who is an expert on matters concerning the use of and writing > of vc++ > dlls for vb then e-mail me and I will send you the visual c++ dll and > source > and the vb demo program and source. BTW I am using visual studio 6 to do > all this. > -- > Jonathan Wilson > http://www.--.com/ Sent via Deja.com http://www.--.com/ Before you buy.
Sat, 06 Jul 2002 03:00:00 GMT

Adheer Pa #2 / 8	I need help from a vb and vc++ expert Jonathan, When you are calling the VC++ DLL's from your program , check the declaration , the data types and ByRef / ByVal properties. You may need to change the data-types from VC DLL to VB , probably that's what is causing the problem. Regards, Adheer. Quote: > I am having trouble getting vb to call my vc++ dll. Everytime I run my > demo, > I get a GPF. The visual c++ demo program I wrote works fine. If there is > anyone > out there who is an expert on matters concerning the use of and writing > of vc++ > dlls for vb then e-mail me and I will send you the visual c++ dll and > source > and the vb demo program and source. BTW I am using visual studio 6 to do > all this. > -- > Jonathan Wilson > http://members.xoom.com/wilsonj/
Sat, 06 Jul 2002 03:00:00 GMT

Pieter Philippaert #3 / 8	I need help from a vb and vc++ expert Also note that Visual Basic only supports Standard Calls, so don't forget to add _stdcall to the C declaration of your function, i.e.: int _stdcall MyFunction(...) {...} Regards, Pieter Philippaerts http://kpdweb.cjb.net/ Quote: > I am having trouble getting vb to call my vc++ dll. Everytime I run my > demo, > I get a GPF. The visual c++ demo program I wrote works fine. If there is > anyone > out there who is an expert on matters concerning the use of and writing > of vc++ > dlls for vb then e-mail me and I will send you the visual c++ dll and > source > and the vb demo program and source. BTW I am using visual studio 6 to do > all this. > -- > Jonathan Wilson > http://members.xoom.com/wilsonj/
Sat, 06 Jul 2002 03:00:00 GMT

Adam Kehle #4 / 8	I need help from a vb and vc++ expert Also, make sure you pass all strings "ByVal" (see MSDN article about passing strings to DLLs) Adam Kehler Quote: > Also note that Visual Basic only supports Standard Calls, so don't forget to > add _stdcall to the C declaration of your function, i.e.: > int _stdcall MyFunction(...) > {...} > Regards, > Pieter Philippaerts > http://kpdweb.cjb.net/ > > I am having trouble getting vb to call my vc++ dll. Everytime I run my > > demo, > > I get a GPF. The visual c++ demo program I wrote works fine. If there is > > anyone > > out there who is an expert on matters concerning the use of and writing > > of vc++ > > dlls for vb then e-mail me and I will send you the visual c++ dll and > > source > > and the vb demo program and source. BTW I am using visual studio 6 to do > > all this. > > -- > > Jonathan Wilson > > http://members.xoom.com/wilsonj/
Sat, 06 Jul 2002 03:00:00 GMT

Jonathan Wilso #5 / 8	I need help from a vb and vc++ expert I am having trouble getting vb to call my vc++ dll. Everytime I run my demo, I get a GPF. The visual c++ demo program I wrote works fine. If there is anyone out there who is an expert on matters concerning the use of and writing of vc++ dlls for vb then e-mail me and I will send you the visual c++ dll and source and the vb demo program and source. BTW I am using visual studio 6 to do all this. -- Jonathan Wilson http://members.xoom.com/wilsonj/
Sun, 07 Jul 2002 03:00:00 GMT

Jonathan Wilso #6 / 8	I need help from a vb and vc++ expert Don't worry, I figured out the problem. I was allocating an array of 0 elements because the VB constant I was pasing to redim was not declared public in the bas module so therefore the program was gpfing when the dll tried to access memory it wasn't allowed to access. Quote: > Also note that Visual Basic only supports Standard Calls, so don't forget to > add _stdcall to the C declaration of your function, i.e.: > int _stdcall MyFunction(...) > {...} > Regards, > Pieter Philippaerts > http://kpdweb.cjb.net/ > > I am having trouble getting vb to call my vc++ dll. Everytime I run my > > demo, > > I get a GPF. The visual c++ demo program I wrote works fine. If there is > > anyone > > out there who is an expert on matters concerning the use of and writing > > of vc++ > > dlls for vb then e-mail me and I will send you the visual c++ dll and > > source > > and the vb demo program and source. BTW I am using visual studio 6 to do > > all this. > > -- > > Jonathan Wilson > > http://members.xoom.com/wilsonj/ -- Jonathan Wilson http://members.xoom.com/wilsonj/
Sun, 07 Jul 2002 03:00:00 GMT

Jonathan Wilso #7 / 8	I need help from a vb and vc++ expert Don't worry, I figured out the problem. I was allocating an array of 0 elements because the VB constant I was pasing to redim was not declared public in the bas module so therefore the program was gpfing when the dll tried to access memory it wasn't allowed to access. Quote: > Jonathan, > When you are calling the VC++ DLL's from your program , check the > declaration , the data types and ByRef / ByVal properties. You may need to > change the data-types from VC DLL to VB , probably that's what is causing > the problem. > Regards, > Adheer. > > I am having trouble getting vb to call my vc++ dll. Everytime I run my > > demo, > > I get a GPF. The visual c++ demo program I wrote works fine. If there is > > anyone > > out there who is an expert on matters concerning the use of and writing > > of vc++ > > dlls for vb then e-mail me and I will send you the visual c++ dll and > > source > > and the vb demo program and source. BTW I am using visual studio 6 to do > > all this. > > -- > > Jonathan Wilson > > http://members.xoom.com/wilsonj/ -- Jonathan Wilson http://members.xoom.com/wilsonj/
Sun, 07 Jul 2002 03:00:00 GMT

Jonathan Wilso #8 / 8	I need help from a vb and vc++ expert Don't worry, I figured out the problem. I was allocating an array of 0 elements because the VB constant I was pasing to redim was not declared public in the bas module so therefore the program was gpfing when the dll tried to access memory it wasn't allowed to access. Quote: > Also, make sure you pass all strings "ByVal" (see MSDN article about passing > strings to DLLs) > Adam Kehler > > Also note that Visual Basic only supports Standard Calls, so don't forget > to > > add _stdcall to the C declaration of your function, i.e.: > > int _stdcall MyFunction(...) > > {...} > > Regards, > > Pieter Philippaerts > > http://kpdweb.cjb.net/ > > > I am having trouble getting vb to call my vc++ dll. Everytime I run my > > > demo, > > > I get a GPF. The visual c++ demo program I wrote works fine. If there is > > > anyone > > > out there who is an expert on matters concerning the use of and writing > > > of vc++ > > > dlls for vb then e-mail me and I will send you the visual c++ dll and > > > source > > > and the vb demo program and source. BTW I am using visual studio 6 to do > > > all this. > > > -- > > > Jonathan Wilson > > > http://members.xoom.com/wilsonj/ -- Jonathan Wilson http://members.xoom.com/wilsonj/
Sun, 07 Jul 2002 03:00:00 GMT

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