Exception: Index was outside the bounds of the array

[Coen]

Hi,

I'm dealing with a master-detail relationship. A datagrid bound to the
detail data. When navigating through the records (next record:
Me.BindingConte xt(mDv1).Positi on += 1), I notice a delay of about 2 sec's if
the detail datagrid is empty (no records to show for this master-record). The
delay happens only once per application run!! After exception debugging a
found that when this happens a "first chance exception of type
'System.IndexOu tOfRangeExcepti on' is thrown. Who knows how to deal with/solve
this situation?

Regards Coen

[Cor Ligthert]

Coen

Probably something as (roughly typed here)
\\\\
if mDV1.count - 2 > me.bindingconte xt(mDv1).Postit ion then
Me.BindingConte xt(mDv1).Positi on += 1)
end if
///
I hope this helps?

Cor

[Coen]

Hi Cor, thanks for your response.

Unfortunately this is not the case. The delay happens whenever the related
detail table has no related rows to show. This can happen at master row nr 5
of 100, or whatever... Any case the master table is not even near his last
record. The most important issue is that it always happens only once per
application-run, and only if the related detail table has for the current
master record no corresponding detail rows.

Again, any help is welcome.
Regards Coen.

"Cor Ligthert" wrote:

Coen

Probably something as (roughly typed here)
\\\\
if mDV1.count - 2 > me.bindingconte xt(mDv1).Postit ion then
Me.BindingConte xt(mDv1).Positi on += 1)
end if
///
I hope this helps?

Cor

[Cor Ligthert]

Coen,

After that an exception is thrown the "same" next exception takes only some
milliseconds so you will probably not see that however it is probably much
more in your program.

From the information I have now I cannot see what it can be, however it
should than be somewhere in your related table in the way you describe it.

Cor

[Cor Ligthert]

However I agree that there should than be an exception, when you did not as
some people do put an empty Try Catch block around it

Try
do something
Catch
End Try

What is of course the worsest thing in programming so I assume you did not
do that.

Cor

[Coen]

Cor,

I'm not using empty Try Catch blocks. But I have found the cause of this
exception. The exception only occurs when the related datagrid's READONLY
property is put to true. Navigating to the next (master) record without any
related detail records to show (in the datagrid), causes this
IndexOutOfRange Exception. Of course I can work around this like:

grdContacts.Rea dOnly = False
Me.BindingConte xt(mDv1).Positi on += 1
grdContacts.Rea dOnly = True

This works fine, I have tested this successfull. Still I'm supprised this
happens. I think, this was not necessary in VS2002+Framewor k 1.0. I could
check this next wednesday. I wonder if this is logic and necessary, I would
like your opinion of this.

Regards Coen

"Cor Ligthert" wrote:

However I agree that there should than be an exception, when you did not as
some people do put an empty Try Catch block around it

Try
do something
Catch
End Try

What is of course the worsest thing in programming so I assume you did not
do that.

Cor

[Cor Ligthert]

Coen,

I tested this in a program I have, however I see in the related datagrid a
nice header with no rows.

This datagrid is with columnstyles by the way.

Cor

[Coen]

Cor, I suppose you turned on "catching the IndexOutOfRange Exception", via the
Debug menu, Exceptions, CLR exceptions, System,
System.IndexOut OfRangeExceptio n. --> Breaking into the debugger? Otherwise
you'll see only a two sec's delay (only once), but no execute interuption.

I downsized my project, also using a dataset without a dataview, but the
exception is still there, however the remaining code is very basic. I'll
paste it underneath, so maybe you can have a look at it? The form contains
four textboxes (bound to the master table), four navigation buttons, and one
datagrid (detail-rows). A connection is made to the Northwind database
(please modify the connectionstrin g).

Maybe you see a difference with your testcode?
Regards Coen

--------------------- Start Code: -------------------
Imports System
Imports System.Data
Imports System.Data.Sql Client

Public Class Form1
Inherits System.Windows. Forms.Form

Dim myConnection As SqlConnection
Dim mDs As New DataSet
Dim mDa1 As SqlDataAdapter
Dim mDa2 As SqlDataAdapter

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load

myConnection = New
SqlConnection(" server=(local)\ INSTANCE01;Trus ted_Connection= yes;database=no rthwind")
mDa1 = New SqlDataAdapter( "SELECT * FROM Customers", myConnection)
mDa2 = New SqlDataAdapter( "SELECT * FROM orders", myConnection)

'Fill dataset
mDa1.Fill(mDs, "Customers" )
mDa2.Fill(mDs, "Orders")

'Define relation
mDs.Relations.A dd(New DataRelation( _
relationName:=" relCustomersOrd ers", _

parentColumn:=m Ds.Tables("Cust omers").Columns ("CustomerId "), _

childColumn:=mD s.Tables("Order s").Columns("Cu stomerId"), _
createconstrain ts:=True))

'Eventhandlers navigatie
Call AddHandlers()

'Some textboxes databinding to the master table
txtCustomerId.D ataBindings.Add ("Text", mDs.Tables("Cus tomers"),
"CustomerId ")
txtCompanyname. DataBindings.Ad d("Text", mDs.Tables("Cus tomers"),
"CompanyNam e")
txtContactname. DataBindings.Ad d("Text", mDs.Tables("Cus tomers"),
"ContactNam e")
txtPostalcode.D ataBindings.Add ("Text", mDs.Tables("Cus tomers"),
"PostalCode ")

'Bind the datagrid to the detail table via the datarelation
grdOrders.DataS ource = mDs.Tables("Cus tomers")
grdOrders.DataM ember =
mDs.Tables("Cus tomers").ChildR elations("relCu stomersOrders") .ToString
grdOrders.ReadO nly = True 'Set the datagrid to READONLY

End Sub

Private Sub AddHandlers()
'Eventhandler navigate-buttons
AddHandler btnFirst.Click, AddressOf Me.Navigate
AddHandler btnNext.Click, AddressOf Me.Navigate
AddHandler btnPrevious.Cli ck, AddressOf Me.Navigate
AddHandler btnLast.Click, AddressOf Me.Navigate
End Sub

Private Sub Navigate(ByVal sender As System.Object, ByVal e As
System.EventArg s)

'grdOrders.Read Only = False '--> This line prevents the
IndexOutOfRange Exception
With Me.BindingConte xt(mDs.Tables(" Customers"))
Select Case sender.name
Case "btnFirst"
.Position = 0
Case "btnPreviou s"
.Position -= 1
Case "btnNext"
.Position += 1
Case "btnLast"
.Position = .Count - 1
End Select
End With
'grdOrders.Read Only = True '<-- This line prevents the
IndexOutOfRange Exception

End Sub
End Class

[Cor Ligthert]

Coen,

I tried it and no errors (it delays however no exception).

I assume that you have option strict not on, because this row should not be
accepted in my opinion
Select Case sender.name
It has to be
Select Case DirectCast(send er, Button).Name

However that should not give the exception.

Cor

[Coen]

Cor, you are right about the late binding, I have option strict put ON now.
But indeed this is of no influence in this exception matter.

If you are experiencing a delay, something must be happening there. I
suppose you also tried running while all the exceptions set to the "Break
into the debugger" option? Also in your project, something must be causing
the delay...

By the way, using
Dev. env. 7.1.3088
Framework: 1.1.4322 SP1

Coen

"Cor Ligthert" wrote:

Coen,

I tried it and no errors (it delays however no exception).

I assume that you have option strict not on, because this row should not be
accepted in my opinion
Select Case sender.name
It has to be
Select Case DirectCast(send er, Button).Name

However that should not give the exception.

Cor