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Hello guys,
I'm novice in VB 6.0 but have some skill in VC++.
I'm developing COM-server using Visual C++ and "thin client" in VB 6.0 ("late binding").
One of function is present in COM-server as follows:
[id(5), helpstring("method Encoder")] HRESULT Encoder([out] long * Result, [out] long * LastError);
As you see, method "Encoder" receives two pointers to long data type. I can invoke that method from client written on Visual C++, but I can't do that on VB.
Is it possible to call method "Encoder" from VB Client? How?
Or I need to rewrite my COM-server and include two separate methods:
- get_EncoderResult
- get_EncoderLastError
?
Yours sincerely,
Alex Bash
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Both VBScript and VB can't call via IDispatch (what you call "late binding" in VB world) methods that receive arguments ByRef.
You can do this via early binding, though. I see you have your IDL interface defined, so why are you calling this using late binding?
Trying to make bits uncopyable is like trying to make water not wet.
-- Bruce Schneier
By the way, dog_spawn isn't a nickname - it is my name with an underscore instead of a space. -- dog_spawn
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Really?
' Client's code - VB6:
Dim o As Cx, o2 As Object
Dim p1 As Long, p2 As Long
...
Set o = New Cx
Set o2 = o
...
p1 = 0: p2 = 0
o.Encoder p1, p2 ' Call by vtable => early binding
p1 = 0: p2 = 0
o2.Encoder p1, p2 ' Call by GetIdsOfName&Invoke => late binding
p1 = 0: p2 = 0
CallByName o, "Encoder", VbMethod, p1, p2 ' forcible late binding
p1 = 0: p2 = 0
CallByName o2, "Encoder", VbMethod, p1, p2
' Server's code - C++:
STDMETHODIMP Cx::Encoder( long * Result, long * LastError)
{
*Result = 22;
*LastError = 222;
return S_OK;
}
With best wishes,
Vita
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Vi2 wrote:
Really?
' Client's code - VB6:
<code>
Dim o As Cx, o2 As Object
Dim p1 As Long, p2 As Long
...
Set o = New Cx
Set o2 = o
...
p1 = 0: p2 = 0
o.Encoder p1, p2 ' Call by vtable => early binding
</code>
Vi2 wrote:
<code>
STDMETHODIMP Cx::Encoder( long * Result, long * LastError)
{
*Result = 22;
*LastError = 222;
return S_OK;
}
</code>
I don't think a call to Encoder from a VB6 client will work with the above Encoder definition. At least when I attempted to call Encoder from a VB client using the above Encoder definition in a C++ COM object the program crashed. Is this normal behavior? Or, am I overlooking something?
Thanks,
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That's because VC++ can handle [out] parameters - VB cannot. In order to return a logical value back to a VB client your interface's final parameter must be marked as [out, retval]. However, you're wanting to return multiple values which is best suited for SAFEARRAYS.
So your question was:
Is it possible to call method "Encoder" from VB Client? How?
With your current implementation? No
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can someone tell me where to find the dial up info on a winxp pc
In the registry in some file some where where is it please help thank
lata
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I've searched around, maybe not hard enough, but I just can't seem to find a way to input data in "a" textbox as feet and inches without using two textboxes. (Visual Basic.NET 2003)
Does anyone know how I might be able to do this?
The inputed data will be used to compute sqaure and cubic feet later on in code, a dollar amount will be later multiplied to this. If that helps at all.
Thanks Folks,
Dooglo
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I'm sorry for the subject but ashamed as I am, I can't think of how to summerize (or realy even how to say) what I am looking for.
First let me say that I'm not asking anyone to write my code for me or show me step by step but I'm asking more for someone to tell me what I need to look for.
I am trying to figure out how to make a program open files that I click on. I know that is a windows setting and I know how to make my program the default 
My problem is that if I make my text editor the default text editor (tell windows to open all .txt with it) then click on a .txt, it launches my program but it doesn't open the txt file.
My problem is that I don't even know what to search for to find info on this problem.
I'm sure its simple so please don't just discard this as someone who is totaly ignorant. I have taken a hands-on aproach to vb.net as my learnvisualstudio.net lessons teach and so when I got comfortable with the basics I just started writeing and search for things as I need them.
Again, my problem now though is that I don't even know what to search for.
Thank you
2 U.S. coins equal 30 cents and one is NOT a nickle. Hmm..
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Does your app take command-line arguments? When you double-click an item in Windows Explorer, it launches something like this (unless the association is configured differently):
RegisteredApp.exe C:\Path\DocumentYouClickedOn.txt
If your app doesn't process the command-line arguments, you'll never know what file to open on launch.
Your association can be configured to launch your app in different ways, using different command-line args or using DDE, or something else. By default, it'll launch using the above method.
To find out more, just open a window in Explorer, like C:\, go to the Tools/Folder Options menu, then click on the File Types tab. Next, scroll down to TXT (Text Document) and you'll find the definition for TXT and Notepad. You'll find 3 actions if you click on Advanced: Open, Print, and PrintTo. Click on Open, then on Edit and you see that Notepad is launched like this:
C:\WINDOWS\system32\NOTEPAD.EXE %1
The %1 is replaced by the full path to the document that you double clicked on.
RageInTheMachine9532
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IC,
Thank you. I knew how windows handled opening documents but I had no idea how to catch that in my aplication. So now I know where to start (read up on accepting command line options/paramiters)
Thank you very much. This was what I needed to know++.
2 U.S. coins equal 30 cents and one is NOT a nickle. Hmm..
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Hi,
Currently i'm developing a system that store inventory record. In my system, i have a database named "rnz.mdb" and it has a table named "recordsList". The PK for the table is FormSerialNumber. The FormSerialNumber is like this --> 68001-001-001. The 1st 5 digit shows the form code.(68001 is the code for inventory form). The 3 digit in the middle is the item ID and the last 3 digits is the number of changes that have been made to the item(for example, computer upgrading). In the field also, there is a field named "Date". My problem is, my boss want the system to display the latest record for each item and at the same time keep the previous record of each of the item. The previous record will became the record's history. I can do the record history part. My problem is the latest record. How can I extract the latest record for each item from the list of records .
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Try this:
Select * from sometable a
where a.FormSerialNumber = (Select max(b.FormSerialNumber)
from sometable b where a.identifier = b.identifier
This way you select the latest record
Hope this is the answer to your "VB" guestion
Grtz, Guus
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What's the best way to document classes that you write in .NET? I know C# has some XML-comment documentation abilities, but VB .NET is limited. Plus the output of those is rather ugly.
I would like to be able to deliver nice "MSDN-looking" HTML documenation to the developers who will be using my classes, but I don't want to spend more time on the docs than on the code!
Barry Etter
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The support for XML documentation provided by the C# compiler is very nice... using the xml output it produces combined with a tool like NDoc[^] creates very nice "MSDN-looking" documentation. Or if you don't want to use NDoc, you can always create your own XSL stylesheet to process the xml documentation.
It's too bad that the VB.NET compiler does not support the same feature. You may want to look at the following:
http://vb-doc.sourceforge.net/[^]
http://www.fesersoft.com/products/VBXmlComments/[^]
http://vbxmldoc.tor-erik.net/[^]
I haven't used any of these, so I can't offer a recommendation. But one may be what you're looking for.
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How can i compare the value of a Current cell to Previous one in all of my row That are displayed in a datagrid? I got this result but I am Looking for a way which should be more efficient than mine.
Kenny
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Maybe you should check the cells before they are displayed in the datagrid. Usually there is a recordset or an array attached to it. It's easy to compare these. But perhaps this is not your question.
Grtz,
Guus
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I am working on a project in which we have to provide a UI to user in which all frames belonging to a selected mpeg2 video file are displayed. User then assign some attribute to each frame and then we have to store that video with those attributes added to each frame. Can any one give some idea about libraries or API's or controls which can help us.
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Hi all,
Im currently developing a MFC-program in Visual C++ 6.0 that will identifiy a user through his/hers fingerprint.
The C++ program needs to be launched from another program with VBA support (so Im currently testing it in MS Excel)
The C++ program also needs to return a textstring with the username (or ID or some kind of text like "George Lucas")
With my very basic skills in VBScript I have manged to run the C++ program. But is it possible to get something back from the program ??
Im guessing that the C++ program might need some kind of method to communicate back to the VB Script ... ?
Im would be very thankful for any kind of help !
/ daniel
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I have a VB project that loads a C++ DLL.
Declare the following module level API functions in your VB project.
' -- Windows API
Public Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Public Declare Function FreeLibrary Lib "kernel32" (ByVal hLibModule As Long) As Long
' -- Public function in C++ DLL
Public Declare Function Test Lib "mycdll.dll" Alias "test_vb" () As Long
To use the C++ function you can use something like the following.
Note: strDLL holds the fullpath to the C++ DLL
' -- Load the dll
lngRet = LoadLibrary(strDLL)
' -- Check for success
If lngRet <> 0 Then
' -- Run the script
Msgbox Test
Else
MsgBox "Could not load dll '" & strDLL & "'" & DEF_SPACE, vbCritical, DEF_APP_TITLE
GoTo PROC_EXIT
End If
PROC_EXIT:
' -- Clean up
If lngRet <> 0 Then FreeLibrary lngRet
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thank you, I'll look in to it
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You can do that using the Exec method of the WScript.Shell object. The Exec method will return a WshScriptExec object that can be used to monitor the status of the running program, its exit code, and get to it StdIn, StdOut, and StdErr streams.
The docs on the WshShell.Exec method start here[^].
Dim WshShell, oExec
Set WshShell = CreateObject("WScript.Shell")
Set oExec = WshShell.Exec("MyCApp.exe")
Do While oExec.Status = 0
WScript.Sleep 100
Loop
WScript.Echo oExec.ExitCode
RageInTheMachine9532
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Getting access to the StdOut would be great, thank you very much !
*edit*
Got it working now, thanks a bunch !
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say suppose in my desktop application there is a datagrid having 20 records and i want that when i move my mouse pointer on any row then background color of that will be changed say red. i know it is possible in asp.net web application but i dont know how could i get this effect in my window application using vb.net at run time in desktop application not in the web application.if it is possible for any one then please give me small sample code to implement it for desktop application using vb.net
tbhattacharjee
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If you change the Property Selection BackColor in the Grid Proerties page you can get your results. (If I understand your question properly)
Thanks,
Ken
Keshav.
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