Need help with a VB.NET error ... please help! Details within

  • Thread starter Thread starter D P
  • Start date Start date
D

D P

Hello everyone, I am new here and I hope I can get the help I need.

I will be as descriptive as possible!!

I have developed an app using VB.NET that requires making a connection
to an access DB that sits on the same machine in which the app is
running. First off, this works PERFECTLY on my PC, but not on the PC
where it will be running.

It needs to open the local database and generate a snapshot of the
report that is specified ( .... the report DOES exist in the DB by the
same name that is used in code).


Here is the code snippet....
(I am using Northwind.mdb as a test DB!!!)

=============================================

Dim oAccess As Access.Application
Dim sDBPath As String 'path to DB
Dim sReport As String


'Testing
sReport = "Summary of Sales by Year"

' Start a new instance of Access for Automation:
oAccess = New Access.Application


sDBPath = "C:\NorthWindODBC\NorthWind.mdb"

***** Error occurs here on OpenDatabase *****
oAccess.OpenCurrentDatabase(filepath:=sDBPath, Exclusive:=False)

oAccess.DoCmd.Minimize()

oAccess.Visible = False



'Output in snapshot format to a temp file

oAccess.DoCmd.OutputTo(Access.AcOutputObjectType.acOutputReport,
sReport, "Snapshot Format", "C:\NorthWindODBC\temp.snp", False)


'Quit access
oAccess.Quit()

'Free
oAccess = Nothing


==============================================

This works as I mentioned on my PC but not on the PC where it will be
running.

I have dloaded and installed the .NET Framework on the target PC,
installed the latest MDAC.

I have copied the exe and reference file dlls from the bin folder of my
project folder to the target PC ... nothing works. Even creating setup
and installing it.

My PC is Windows XP, and Target is Windows 2000!


The error I get is .....

system.nullreferenceexception: Object Reference not set to an instance
of an object

This error is occuring on the line I indicated above (***)

Any ideas?? Thanks in advance to anyone with any ideas on how to solve
this!

OH .... and I have set permissions and things like that on the DB itself
and the folder where it is located!
 
Hi DP,

I don't see it and if I knew that these questions are often answered I would
not give an answer but wait. However they are not.

Problem is of course that you have to debug on the other computer.

The most probable is that this is the problem.
Dim oAccess As Access.Application
Click to expand...

You can this test of course withouth direct debugging by something as

If oAccess Is nothing then messagebox.show("it is nothing")

I hope this helps anyeway?

Cor
 
D P said:
Hello everyone, I am new here and I hope I can get the help I need.

I will be as descriptive as possible!!

I have developed an app using VB.NET that requires making a connection
to an access DB that sits on the same machine in which the app is
running. First off, this works PERFECTLY on my PC, but not on the PC
where it will be running.

It needs to open the local database and generate a snapshot of the
report that is specified ( .... the report DOES exist in the DB by the
same name that is used in code).


Here is the code snippet....
(I am using Northwind.mdb as a test DB!!!)

=============================================

Dim oAccess As Access.Application
Dim sDBPath As String 'path to DB
Dim sReport As String


'Testing
sReport = "Summary of Sales by Year"

' Start a new instance of Access for Automation:
oAccess = New Access.Application


sDBPath = "C:\NorthWindODBC\NorthWind.mdb"

***** Error occurs here on OpenDatabase *****
oAccess.OpenCurrentDatabase(filepath:=sDBPath, Exclusive:=False)

oAccess.DoCmd.Minimize()

oAccess.Visible = False



'Output in snapshot format to a temp file

oAccess.DoCmd.OutputTo(Access.AcOutputObjectType.acOutputReport,
sReport, "Snapshot Format", "C:\NorthWindODBC\temp.snp", False)


'Quit access
oAccess.Quit()

'Free
oAccess = Nothing


==============================================

This works as I mentioned on my PC but not on the PC where it will be
running.

I have dloaded and installed the .NET Framework on the target PC,
installed the latest MDAC.

I have copied the exe and reference file dlls from the bin folder of my
project folder to the target PC ... nothing works. Even creating setup
and installing it.

My PC is Windows XP, and Target is Windows 2000!


The error I get is .....

system.nullreferenceexception: Object Reference not set to an instance
of an object

This error is occuring on the line I indicated above (***)

Any ideas?? Thanks in advance to anyone with any ideas on how to solve
this!

OH .... and I have set permissions and things like that on the DB itself
and the folder where it is located!
Click to expand...
Do you have a full installation of the same version of MS Access on the
target PC as exists on the development PC?
You don't need Access installed to use an Access database with VB.NET, but
you are using an Access application object.
 
* D P said:
I have developed an app using VB.NET that requires making a connection
to an access DB that sits on the same machine in which the app is
running. First off, this works PERFECTLY on my PC, but not on the PC
where it will be running.

It needs to open the local database and generate a snapshot of the
report that is specified ( .... the report DOES exist in the DB by the
same name that is used in code).


Here is the code snippet....
(I am using Northwind.mdb as a test DB!!!)

=============================================

Dim oAccess As Access.Application
Dim sDBPath As String 'path to DB
Dim sReport As String


'Testing
sReport = "Summary of Sales by Year"

' Start a new instance of Access for Automation:
oAccess = New Access.Application


sDBPath = "C:\NorthWindODBC\NorthWind.mdb"

***** Error occurs here on OpenDatabase *****
oAccess.OpenCurrentDatabase(filepath:=sDBPath, Exclusive:=False)
Click to expand...

Ever thought of posting to an Access group?
 
Hi Peter,

Was already answered as this by Armin in the other thread in this double
post 2 hours ago.

Cor
 
Hi Peter,

I shall be wrong, however when I readed your message after I had readed the
solution from Armin one hours before, which was the same as yours, I
thought will we all do that who are active in this newsgroup.

However probably it was just an coincident.

Cor
 
Cor Ligthert said:
Hi Peter,

I shall be wrong, however when I readed your message after I had readed the
solution from Armin one hours before, which was the same as yours, I
thought will we all do that who are active in this newsgroup.

However probably it was just an coincident.

Cor
Click to expand...
Yes it *was* a coincidence. No probably about it. I had not seen the other
thread started by the same OP, nor had I looked for such a thread.
I, like many others here, have limited time to read and respond to requests
for help. When I see a post where I believe I may have an insight, I
respond. I don't scour the newsgroups looking for the possibility that the
OP posted the same question in the same, or other groups multiple times.
The way I see it, a question answered twice is far better than a question
unanswered.
 
Back
Top