Visual Basic

Re: Simple transactional updating in .Net

9-Jul-07 4:23

Easy. All you have to do is read the documentation on System.Transactions[^]

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

MatthysDT9-Jul-07 5:17

MatthysDT

9-Jul-07 5:17

Thank You!
That seems to be what I needed!

_______________________________________________________________________
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"you can't forget something you never knew..." M. Du Toit

error when commiting the row to the original data store(urgent)

cutequencher8-Jul-07 23:14

cutequencher

8-Jul-07 23:14

i am having this error when i am about to delete a data row

inline with this is a message box saying:
object reference not set to an instance of an object. do you want to correct the value?

if i click yes, it will delete the row if no it will ignore the deletion

i've already checked all of my declarations and pretty sure that i've declared everything right. please help me about this. thanx!

Re: error when commiting the row to the original data store(urgent)

Tom Deketelaere8-Jul-07 23:48

Re: error when commiting the row to the original data store(urgent)

8-Jul-07 23:48

Normally this error acurs when you are accessing a variable that hasn't been initialized yet

for instance

dim s as datatable

s.delete... ' this will give your error

s = new datatable...

The right way would be

dim s as datatable
s= new datatable...
s.delete...

the best way to check if this is the case is asinging a stander value to your variables and then try it again if you still get te error something else is going on

cutequencher8-Jul-07 23:57

cutequencher

8-Jul-07 23:57

it has nothing to do with the declaration... ive just mentioned that i already checked the declaration. it has something to do with the datagrid, its properties and errors bound to it. but thanx anyway.

Re: error when commiting the row to the original data store(urgent)

Dave Kreskowiak9-Jul-07 4:19

Re: error when commiting the row to the original data store(urgent)

9-Jul-07 4:19

OK. You're calling a method or setting/reading a property on what you think is a valid object that isn't actually pointing to an instance of an object. In other words, you're trying to do something like Nothing.Method(params). Obviously, Nothing, or null in C# doesn't have any methods or properties, so this will throw the message you're talking about.

There is nothing wrong with the DataGrid that will cause this problem. It's being thrown by code you wrote. Perhaps you're calling a method on an object your code is assuming exists, probably as a return value from a method, or as an object in a collection where the collection doesn't have any objects in it, when it should be checking for the existance of an object before it tries to use it.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

cutequencher9-Jul-07 14:28

cutequencher

9-Jul-07 14:28

ok i get it... but how could i resolve the problem? i am trying to catch the error but the try and catch does'nt work with it. thanx!

Re: error when commiting the row to the original data store(urgent)

Dave Kreskowiak10-Jul-07 12:24

how to create ocx (activex) control in vb.net

10-Jul-07 12:24

The problem is going to be in either the code that setup the DataAdapter or TableAdapter that you're using, or in the code you're using to do the Update. Without seeing any of this code, it's impossible for anyone to tell you what's wrong.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Tom Deketelaere8-Jul-07 23:07

8-Jul-07 23:07

I've found out that in order to use my user controls in ms access I'll need to write them as activex controls (ocx) but I can't seem to get it working in vb.net.

Anyone have any experiance doing this?

Vasudevan Deepak Kumar9-Jul-07 2:07

Vasudevan Deepak Kumar

9-Jul-07 2:07

Will this help you?

http://www.codeproject.com/cs/miscctrl/htmlwincontrol.asp[^]

Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips

Tom Deketelaere9-Jul-07 3:11

9-Jul-07 3:11

I've been looking at that one for the better part of the day now and can't seem to get it working.

It could be that it works fine for use on the web but I have to use it in access so...

I'v been reading alot about this and it seems it is no longer supported by microsoft in the .net2 wich really suckes how am I supposed to get my user controls into access now Sigh | :sigh:

Dave Kreskowiak9-Jul-07 4:13

9-Jul-07 4:13

TDDragon wrote:
I'v been reading alot about this and it seems it is no longer supported by microsoft in the .net2

WHA??? Who told you that?? Attributing a class for COM Interop is very much supported, even into .NET 3.0 and 3.5.

How do you have your class/methods/properties attributed?? Was the resulting .DLL registered on the target machine using REGASM?? Regsrv32 won't work with a .NET assembly.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Tom Deketelaere9-Jul-07 4:30

9-Jul-07 4:30

when I try to register it on the target machine it gives me an error

as for where or who told me that there was no support I can't really answer that beceause I don't know anymore (I'v been reading articles and blogs all day long and everything is starting to bee very blurry)

I'v added the following to my class:
<Guid("1376DE24-CC2D-46cb-8BF0-887A9CAF3014"), ClassInterface(ClassInterfaceType.AutoDual), ProgId("Preview.PreviewDialog")> Public Class PreviewDialog
...

<ComRegisterFunction()> Public Shared Sub RegisterClass(ByVal key As String)
Dim sb As New StringBuilder(key)
sb.Replace("HKEY_CLASSES_ROOT\", "")
Dim k As RegistryKey = Registry.ClassesRoot.OpenSubKey(sb.ToString(), True)
Dim ctrl As RegistryKey = k.CreateSubKey("Control")
ctrl.Close()
Dim inprocServer32 As RegistryKey = k.OpenSubKey("InprocServer32", True)
inprocServer32.SetValue("CodeBase", Assembly.GetExecutingAssembly().CodeBase)
inprocServer32.Close()
k.Close()
End Sub
<ComUnregisterFunction()> Public Shared Sub UnregisterClass(ByVal key As String)
Dim sb As New StringBuilder(key)
sb.Replace("HKEY_CLASSES_ROOT\", "")
Dim k As RegistryKey = Registry.ClassesRoot.OpenSubKey(sb.ToString(), True)
k.DeleteSubKey("Control", False)
Dim inprocServer32 As RegistryKey = k.OpenSubKey("InprocServer32", True)
k.DeleteSubKey("CodeBase", False)
k.Close()
End Sub

when I build this it seems that he is trying to register it but isn't able to do so for the vbpowerpack.dll so I'm currently writing a simple usercontrol without the vbpowerpack to see if it makes a difference

My control is visible already in the insert add-in menu of access but I get an error when I try to do soo.

I'm currently thinking (hoping) its because of the vbpowerpack

Tom Deketelaere9-Jul-07 4:49

9-Jul-07 4:49

After creating a very simple user control (contains just a button and checkbox and no code) it would seem that my code above indeed works fine (I can use this user control in access 2003 (still have to find it in 2007 but don't expect much trouble there))

So apperently it was the vbpowerpack that gave me so much trouble Sigh | :sigh:

still have to see how I can make access catch events and get property's from my user control but that at least I can get my user control to display on a form already Big Grin | :-D

thanks for the assistence

Null value

magedhv8-Jul-07 23:07

magedhv

8-Jul-07 23:07

please help
i wanna make a code that tell visual basic if the value of ("reglz")= dbnull then
go to err1:
when i type that ,he underline the word dbnull (u can't use it as experision

here is my code

        cmd.CommandText = "select sum(fatrq1)reglz from reglz where fatrname = '" + ComboBox1.Text + "'"<br />
        'fatrq1<br />
        dr = cmd.ExecuteReader<br />
<br />
        dr.Read()<br />
<br />
<br />
        If f = DBNull Then<br />
            GoTo hh<br />
<br />
        End If<br />
<br />
        f = dr("reglz")<br />

any suggestion ???

Re: Null value

Nilesh Hapse8-Jul-07 23:20

Nilesh Hapse

8-Jul-07 23:20

Pls use IsDBNull

Re: Null value

Vimalsoft(Pty) Ltd8-Jul-07 23:26

Vimalsoft(Pty) Ltd

8-Jul-07 23:26

Go to this Article
http://www.codeproject.com/useritems/VBNET_Null_Values_in_Int.asp[^]

Vuyiswa

Re: Null value

Tom Deketelaere8-Jul-07 23:37

vb6 code doesn't work in VBA(ms access).

8-Jul-07 23:37

replace your code with the following

if isdbnull(f) then
goto hh
end if

Asif Rehman8-Jul-07 22:15

Asif Rehman

8-Jul-07 22:15

I have microsoft fingerprint reader. its SDK from griule.com.
samples provided with SDK are in VB6,VB.NET,C#.NET etc.
but I need samples to work in MS.ACCESS2003.

all work fine when I copied all the code from VB6 to VBA(ms access).
here's what I have to changes.
1). made a public variable to refer to form.(Public frmMain As Form) as VB6 has a form with name(frmMain).

here's what I experience when I call a function.

herers the definition provided in for VB6.

Function CapRawImageToHandle (ByRef RawImage As Variant, ByVal width As Long, ByVal height As Long, ByVal hdc As Long, ByRef handler As IPictureDisp) As Long

'Call to function in VB6
frmMain.ctrl.CapRawImageToHandle raw.img, raw.width, raw.height, frmMain.hDc, handle

I got an error application-defined or object-oriented error.
I guess frmMain.hDC is causing problem as I don't know how to refer to ms access form's hDC property.

Asif Rehman

Re: vb6 to VBA(I found solution). But

Asif Rehman8-Jul-07 22:57

Asif Rehman

8-Jul-07 22:57

I have changes frmMain.hdc to frmMain.hWnd
now it works fine but.

I've got Image Control on form. and want to show the image taken from
handle variable.

' handle to finger image
Dim handle As IPictureDisp
frm.GrFingerXCtrl1.CapRawImageToHandle raw.img, raw.width, raw.height, frm.Hwnd, handle

    ' draw image on picture box
    If Not (handle Is Nothing) Then
        formMain.img.Picture = handle
    End If

it gives error when I update Image Control(msaccess) in this way.(file not found).

Asif Rehman

VB.net user controls in Access 2007

Tom Deketelaere8-Jul-07 21:39

Re: VB.net user controls in Access 2007

8-Jul-07 21:39

I posted this a last week (I know) but didn't get an answer that helped me.
the answer I did get showed how to ad standard vb.net controls to a toolbar but this is not exactly what I want (maybe my question wasn't specific anough) so let's try again.

I have developed a user control in vb.net (it displays all files in a folder with a previeuw and some additional information and functions)

Now my boss asked me to see if we can't use it in "ms access 2007" since I'm very new to access (about 1 month user and developer now) I have no idee of how to get started at this.

basicly I need to be able to create a new form that holds my vb.net user control on it and is able to catch certain events (declared in the user control)

Any help on this would be appriciated (I looked on the internet but al I could find was how to put controls in the toolbar (to be clear this is not what I want my controls need to go on the form itself))

Thanks in advance

Paul Conrad29-Jul-07 6:07

Paul Conrad

29-Jul-07 6:07

Have you figured out if this is possible?

"Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

Re: VB.net user controls in Access 2007

Tom Deketelaere29-Jul-07 20:46