Visual Basic

1-Jan-03 19:43

Thanks ! I'll look up the book

Oh yeah, and Happy New Year

Notorious SMC

The difference between the almost-right word & the right word is a really large matter - it's the difference between the lightning bug and the Lightning
Mark Twain

Get your facts first, and then you can distort them as much as you please
Mark Twain

Strange COM error

ProffK17-Dec-02 20:52

ProffK

17-Dec-02 20:52

In an ActiveX dll have an object called Merge, and its method called Import has rudimentary error handling. The basics of Import are shown below. When I call Import from a client, whether I’m connected to the .dll or to the .vbp, with an incorrect database or table name, I get the following error:

Method ‘Import’ of object ‘_Merge’ failed.

Now if I put a break point on my ‘Err.Raise’ line, execution stops there, but when I single step, it returns to the client project with the above error. If, when stopped on that line, I paste it into the immediate window, I get a good error message.

Could this maybe have to do with the fact that the project used to be an ActiveX .exe, and I just recompiled it as a .dll?

Public Function Import(ExecuteDatabase As String, PropagateDatabase As String, TableName As String, FileName As String) As Boolean

Dim strServer As String
Dim strDatabase As String
Dim flgTrans As Boolean

On Error GoTo ErrProc
Import = False

'Connect to configured server and database.
Set objSrv = New SQLServer
strServer = QueryProfile("Database", "Server", "(local)")
strDatabase = QueryProfile("Database", "Database", "cc_online")
objSrv.Connect strServer, "sa", ""
Set objDb = objSrv.Databases(strDatabase)
Set objTable = objDb.Tables(TableName)

...
...
...
Exit Function

ErrProc:
Err.Raise vbObjectError + 2000, "Merge.Import", "Import for table " & TableName & " failed: [" & Err.Description & "]"

End Function

byref t ype mismatch

ns17-Dec-02 9:09

17-Dec-02 9:09

I have the C dll:

#include <windows.h>
#include <stdio.h>

int _stdcall CallMe(int *a, int *b)

{ 
char ab[20];

sprintf(ab,"The value of a is %d \n",a);
MessageBox (NULL, ab, "Test DLL", MB_OK); 
b = a;

return 0; 

}

with the .def file:

LIBRARY builderDll 
EXPORTS 
CallMe (int *a, int* b) @1

I call this from VB as follows:

Private Declare Function CallMe Lib "C:\PMARModif\builderDll\Debug\builderDll.dll" (ByVal a As Long, ByRef b As Long) As Long
Private Sub Command1_Click()

Dim a As Integer
Dim b As Integer
a = 10

CallMe a, b

Form1.Print b
End Sub

When I try to run I get a byref argument type mismatch pointing at b

Appreciate your help,
ns

Re: byref t ype mismatch

Nick Seng17-Dec-02 17:08

Event Handling in VB.Net WebForms

17-Dec-02 17:08

at first glance, i would say that you're passing in long when the function takes int ??????

Notorious SMC

Regular Expressions

mikasa17-Dec-02 6:34

mikasa

17-Dec-02 6:34

Ok, I am trying to make an Expression to evaluate a Short Time format (hh:mm). I've seen the standard format of "\d\d:\d\d" but I can't use it because it allows values greater than 23 for the Hour.

I've come up with one but I need help on the 2nd digit in the hour. Basically in laymen's terms it goes something like this: (1 or 2)(??):(0 - 5)(0 - 9). The Regular Expression looks like this: "[1,2](Nothing here??):[0-5]\d".

Here's what I need to do. If the first Digit is a "1", then the 2nd digit can be "\d" or "[0-9]" (for hours 0 - 19) . Otherwise, if the first digit is "2", then the 2nd digit can only be "[0-3]" (for hours to 20 - 23).

Can anyone help?

rohancragg17-Dec-02 4:08

rohancragg

17-Dec-02 4:08

I got the following code (C#) from a VSj article and dont know how I would translate it to VB.Net, can anyone help?

What we are doing is adding a series of LinkButtons to a table on the page, assigning the CommandName and Text programmatically:

---

System.WebControls.LinkButton btn = new LinkButton();
// assign various properties of the button...
btn.Click += new new System.EventHandler(btnClick);

---

the above code presumably assigns the event to a single event handler that will then be used to work out which button fired the event and act according to the CommandName

But I dont know how to do similar in VB.Net.

Thanks for any help...

Rohan. WTF | :WTF:

Re: Event Handling in VB.Net WebForms

Nick Seng17-Dec-02 16:58

Re: Event Handling in VB.Net WebForms

17-Dec-02 16:58

i'm not too sure with what the code is trying to do( haven't really gotten into C# yet Frown | :(

) but if it's event handling you want, this might be what you're looking for:

Friend WithEvents Btn as new System.Web.UI.WebControls.LinkButton()<br />
<br />
Private Sub btnClick(arguments) handles btn.click<br />
coding<br />
End Sub<br />

I hope that's what you're loking for! Smile | :)

Notorious SMC

rohancragg17-Dec-02 22:46

rohancragg

17-Dec-02 22:46

The point of this is that I am programattically adding buttons at
runtime so I cannot have an individual event handler for each one as I
dont know how many there will be. However, the code translator at:

http://www.aspalliance.com/aldotnet/examples/translate.aspx

has helped me find the solution:

btn.Click += new System.EventHandler(btnClick)

would translate to:

AddHandler btn.Click, AddressOf btnClick

Thanks, Rohan Smile | :)

Re: Event Handling in VB.Net WebForms

Nick Seng17-Dec-02 23:24

Want to do this in VB - involves C pointers...

17-Dec-02 23:24

No, Thank You!! I learned something new today Blush | :O

Notorious SMC

ns17-Dec-02 1:49

17-Dec-02 1:49

The Following bit of code:

'    int nalg = 10
'    int* score = new int[nalg];
'
'    for (int n = 0 ; n < nalg ; n++) score[n] = 10*(n+1);
'
'
'    // call the function
'
'    int fusion_score;
'
'    Fusion_Method(&nalg, score, &fusion_score);

How would I write this in VB. Fusion_Method is a function in a C Dll that I am "loadLibrary"ing into the VB calling code.

Thanks!

Appreciate your help,
ns

Re: Want to do this in VB - involves C pointers...

CT CHANG19-Dec-02 16:33

CT CHANG

19-Dec-02 16:33

Perhasp you can try with the varptr to pass the pointer into the Fusion_Method function.

K-PAX? CHANGE THE WAY YOU LOOK AT YOURSELF, OTHERS & THE WORLD...

VB DLL for C App

NoizeGod16-Dec-02 16:36

NoizeGod

16-Dec-02 16:36

Thanks in advance,

I'm trying to author a DLL plugin for an existing application that was written in C. In other words, the C code can not change. Unfortunately, the app doesn't implement COM and I'm writing the DLL in VB6 which only implements ActiveX DLL (using COM). The app does support loading all the DLL's in a certain directory and I've got a sample header file for the function call syntax. Unfortunately, I know VB and not C so I'm trying to convert the header into VB.

I've found a way to export the functions from my DLL and the calling app does recognize them, so step 1 is out of the way. The next step is to manually initialize COM on the calling thread so VB will play nice? Then TLS can be loaded?

I think these are the correct steps but obviously, I'm having implementing them. Does anybody have any leads, examples and/or links where I can learn about this more? Surely somebody has written VB plugins for a C app?

Confused | :confused:

Thanks

Joe

Re: VB DLL for C App

CT CHANG19-Dec-02 16:29

CT CHANG

19-Dec-02 16:29

if the C code can not be change, then you how invoke the VB DLL in your C app?

K-PAX? CHANGE THE WAY YOU LOOK AT YOURSELF, OTHERS & THE WORLD...

Re: VB DLL for C App

NoizeGod19-Dec-02 17:20

NoizeGod

19-Dec-02 17:20

K-PAX, Thanks for responding.

As mentioned in my original message, "The app does support loading all the DLL's in a certain directory".

Thanks

Joe

Re: VB DLL for C App

CT CHANG19-Dec-02 17:32

CT CHANG

19-Dec-02 17:32

i miss that. As you have the header file for the DLL export function prototype which going to load by the C app. So i guest developing the Dll with C/C++ is the choise. As VB can not create normal WIN32 DLL as the LoadLibrary API need a valid dll entry point which does not generated in VB ActiveX Dll.

K-PAX? CHANGE THE WAY YOU LOOK AT YOURSELF, OTHERS & THE WORLD...

Do I Need To Close SQL Connection

yccheok15-Dec-02 19:33

yccheok

15-Dec-02 19:33

here is the portion of source code to retrieve data from database
---------------------------
Dim dr as SQLDataReader
Dim cmd as SQLCommand
Dim cnn as SQLConnection

cnn=new SQLConnection(ConfigurationSettings.AppSettings("ConnectionString"))
cnn.open()
cmd=new SQLCommand(sqlstr,cnn)
dr=cmd.ExecuteReader()

do while dr.read()
hp=dr("handphone")
loop

dr.close()
---------------------------

i was wondering do i need to close the SQLConnection cnn ?or when i close SQLDataReader dr, cnn will automatically be closed?

thank you.

regards
yccheok

Re: Do I Need To Close SQL Connection

Nick Seng17-Dec-02 16:51

17-Dec-02 16:51

You should close the connection only after you are done with the data reader. Fortunately, there is a way to automatically close the connection when you close the data reader, that is by supplying the following argument in the ExecuteReader Function:-

cmd.ExecuteReader(CommandBehavior.CloseConnection)

Notorious SMC

Application Path

SuperGeek15-Dec-02 15:21

SuperGeek

15-Dec-02 15:21

Here is what I hope will be a simple question. In the old VB6, we could use the app.path to get the application path. What do I used to do this in VB.NET?

Wayne Phipps15-Dec-02 18:48

15-Dec-02 18:48

Is this is what your looking for...

The following example gets this property and displays its value in a text box. The example assumes that textBox1 has been placed on a form.

Private Sub PrintStartupPath()<br />
   textBox1.Text = "The path for the executable file that " & _<br />
      "started the application is: " & _<br />
      Application.StartupPath<br />
End Sub

Nick Seng17-Dec-02 16:11

17-Dec-02 16:11

Application.StartupPath only works in Vb6

In vb.net, you have 2 choices that work:

1) System.Reflection.Assembly.GetExecutingAssembly.Location

2) System.IO.Directory.GetCurrentFolder

I hope this helps

Notorious SMC

Wayne Phipps17-Dec-02 21:55

17-Dec-02 21:55

If Application.StartupPath is only applicable to VB6 then why did that sample come from the .Net Framework class library? I ask this question because I have just upgraded from Visual Studio 6 to Visual Studion .Net Pro and this sample came from the .Net help. Visual Studio 6 is now not installed.

Here is the complette sample...

.NET Framework Class Library

Application.StartupPath Property [Visual Basic]

Public Shared ReadOnly Property StartupPath As String

Property Value
The path for the executable file that started the application.

Example
[Visual Basic, C#] The following example gets this property and displays its value in a text box. The example assumes that textBox1 has been placed on a form.

Private Sub PrintStartupPath()<br />
   textBox1.Text = "The path for the executable file that " & _<br />
      "started the application is: " & _<br />
      Application.StartupPath<br />
End Sub

Requirements
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows .NET Server family

.NET Framework Security:

FileIOPermission for reading and writing files. Associated enumeration: FileIOPermissionAccess.Read

See Also
Application Class | Application Members | System.Windows.Forms Namespace

Wayne Phipps17-Dec-02 22:35

17-Dec-02 22:35

I just tried it in VB.Net by the following:

TextBox1 = Application.StartupPath

Worked fine
Poke tongue | ;-P

Nick Seng17-Dec-02 23:13

17-Dec-02 23:13

BusterG wrote:
TextBox1 = Application.StartupPath

This is really weird coz Application.StartupPath doesn't work for me! Is there some other namespace or something that i'm suppose to add??? Unsure | :~

Notorious SMC

Wayne Phipps18-Dec-02 0:06