I'm hoping someone can assist. I'm still learning VB so excuse my lack of knowledge. The below code is a mashup of a code snippet I found that effectively reads from an SQLite database. The initial code snippet consisted of a textbox for input, a textbox for output, and also consisted of a datagrid to store the contents and a button to activate the lookup.
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I have one list that pushes to another list. Think of a shopping cart situation. If you double-click on the white area after the list of items in the first window, I get a null exception error when I push the info to the second window. How can I avoid that error??
Existing Code is below...
Private Sub lstBooksAudio_doubleclick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lstBooksAudio.DoubleClick
If lstBooksAudio.SelectedItem = "" Then
MsgBox("Please Click on an item.")
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I am trying to create a treeview in VB.net, the data has to be loaded from MSAccess 2010 database. When I try to run this program I get error : Argument Null Exception was unhandled, 'column' argument cannot be null and the program crashes. I have pasted the code as under:
Imports System.Data.OleDb
Public Class frmRating
Private Sub frmRating_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles
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I am building a VB.net application using VB Express 2008 which connects to a MySQL database. Right now, I am only selecting records, but will be writing code for update / insert. I have installed the MySQL Net Connector, most recent stable build. I have set a reference to it in project references. It makes a connection and reads just fine, no issues there at all.
My problem is this: When exiting the project (via calling "End") I am receiving a null Exception error. Here is the error[code]....
It's saying I cant access this object in my class. Why? I'm pretty sure Ive used this method several times before. Below is some bits of code to figure this out. Object reference not set to an instance of an object."
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Public Class Form1
Dim int As Integer = 0
Dim CustomerTable As New DataTable
Dim instance As New InvalidOperationException()
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This is the code this exception occurs when i click on the home button of my webbrowser.or i enter any site on the combobox.
I am loading data from an excel sheet using the following code.The first test I did worked fine.But when I tried another sheet it errored on a cell that was blank"Object reference not set to an instance of an object".Even though the sheet in the first test had blank cells.I need the loop to load the blank cell in the datatable
For nRow = 1 To objSheet.UsedRange.Rows.Count - 1
dr = dt.NewRow
For nCol = 0 To objSheet.UsedRange.Columns.Count - 1
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In the following code an error arises because the date being passed to the cDate function is Null. However, the catch statement is in error and reports index out of range on the Catch Ex as Exception line. The exception helper says the word Exception is in error and advises that it is index out of range.
View 12 RepliesI am working on a vb windows form application with several connected forms. Its used to manipulate a MySQL database. One of the sub-forms has the following code snippet:
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i have the following code but when i select button1 i get the following error: Null Reference Exception was unhandled-object reference not set to an instance of an object. - any idea's how to fix it ?i have underlined the line of code that is highlighted when the error occurs
Imports System.Data
Public Class Form1
Dim Ping As Net.NetworkInformation.Ping
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I've moved my Database connection string into my app.config - however its causing a null exception error when i use it
App.Config
vb
<connectionStrings>
[Code].....
Not sure what I am doing wrong, but here is the code.
SQL Server Express 2008 R2
VB 2010
Private Sub FillDataSetAndViewGrid()
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I am getting a "null reference exception" error when I run my application, this error occurs even before the webbrowser has navigated anywhere. Why would I get this error without a webbrowser document complete occurring?
vb
Dim HTML As String = WebBrowser2.Document.Body.InnerHtml.ToString
If HTML.Contains("Submit Comment") Then EnterData() Else NextURL()
End If
I don't understand why I would get this error when I haven't even navigated anywhere? Forgot to say that this code is inside WebBrowser2 document_complete.
I am working on creating an application (game) for a PocketPC with Visual Studio2005 in VB/.NET. I try to dynamically create a (new)button upon clicking a label and assigning certain properties to this button. For this I used below displayed code, but this button does not appear on 'Form1' - which is big enough to display it- but creates an error: A NullReferenceException. Such occurs when you try to reference an object in your code that does not exist, but I think I just did by using'..New..' Who can tell me what is wrong and how to fix this? [Code]
View 16 RepliesBackground: I wrote code that will output all the currently logged in User's Active Directory group names. I want the group name (ex: Acomp_user_BIG) via IdentityReference.Translate instead of the current user's SID's (ex: S-1-5-32-544) returned via IdentityReference.Value.
Here is code that I used:
Public ReadOnly Property Groups As IdentityReferenceCollection
Get
Dim irc As IdentityReferenceCollection
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Due to this error I am getting a default date 1/1/1900. Variable 'dr' and 'dr1' is used before it has been assigned a value. Here's the code:-
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Warnings: Variable 'targetPath' is used before it has been assigned a value. A null reference exception could result at runtime.
View 39 RepliesI have a fairly simple piece of code:
Private _PurchaseDelivery as PurchaseDelivery
Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As PurchaseDeliveryItem)
[Code]....
Which is inside a class which overrides a custom list base. The code is occassionaly throwing an unhandled exception, System.NullReferenceException, on this line when used in production:
If _PurchaseDelivery IsNot Nothing AndAlso _PurchaseDelivery.DefaultSKUBinID.HasValue Then
DeafultSKUBinID is declared as an Integer? (Nullable Int) in the PurchaseDelivery class. I cannot see what might be causing this error, why would this be returning an error?
I've placed a treeview on my form and when debugging everything works as planned. However, when I publish the application and run it on another machine, I get a null reference exception. This form is an MDIchild and another form in the same child collection loads its TreeView data with no problem.Here's my code, MajorCategories(), MiddleCategories(), MinorCategories() are all arrays of Structures filled in an outside subroutine.
Private Sub CategoryMaintenance_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
RedrawTree()
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When I put a break point to the last if clause in the sub ("If (backOrder < 0) Then", see below) it runs until the break point, if I put the break point further below, I get the following error:
Cannot insert the value NULL into column 'OrderID', table 'WHM.dbo.OrderDetails'; column does not allow nulls. INSERT fails. The statement has been terminated.
I've discovered first hand that it only happens when prodqty is bigger then qtyOnStock, thus executing the if clause.
The code:
Private Sub NCOSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NCOSubmit.Click
Dim sqlText As String = ""
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I tried adding a loop inside this loop but continue to get the error "Null reference exception was unhandled" before the loop ends.
For rowIndex = 0 To dgvVisit.RowCount - 2
MessageBox.Show(dgvVisit.Rows(rowIndex).Cells("CoPayCharge").Value.ToString)
For rowIndex1 = 0 To dgvPayment.RowCount - 2
MessageBox.Show(dgvPayment.Rows(rowIndex).Cells("CoPayPaid").Value.ToString)
Next
Next
n my project i am to enter a name and a test mark into two separate text boxes and then select the button to store the information into the arrays, one array for names and another for marks, but when it is reset using the Erase <Array> fuction andi try to re enter information, no matter what information is entered i get a "Null Reference Exception Unhandled" Error.I am using Visual Basic 2008.My code is as it says from now:
Public Class frmAdverageTestMarkCalculator
Dim ClosingMsg As String
Dim Closingtitle As String
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I imported an app from vb6 to vb.net It works fine. It has one axmsflexgrid control. Now I want to add another axmsflexgrid control in the same app. I tried to copy and paste from one frame (groupbox) to another and got this error:
"An error occurred while processing this command: Exception from HRESULT:0x800A018A (CTL_E_GETNOTSUPPORTED)"
An inputs on how would I fix this? Or just make a new axmsflexgrid?
I am testing a program, and I am getting a null reference error at this line. oParent.Invoke(oParent.cUpdatingSolidWorks, iSolidWorksItem). I have stepped through the program, and all the items are created. A watch window with the three objects all have data in them. I am wondering what would cause this error if the objects exist. [Code]
View 5 RepliesI have built my project successfully but when I run App. I get error message:value cannot be nullParameter name: activationContext
View 3 Repliesvisual basic application prompting me a message "Object reference not set to an instance of an object". i have 2 project in one solution. One is developed in c# and other is in vb. i am calling a method of c# project in vb project. the vb code is:[code]when i debug vb project individually it works properly and when i call vb application from c# application, it prompting error. is i missed out any .net framework reference? [code]
View 1 RepliesI have a module and form. Module has a structure.
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Actually values are not stored in that array list permanently. its storing temporarily and then destroying. i want to store that values in that arraylist permanently.
Can anyone give me some easy to understand exception-handled error messages, like this:
Catch parameter As SqlException MsgBox("Unable to save record due to invalid parameters.", MsgBoxStyle.Information, "Unable To Save Record")dbConn.Close()for the following events:
- During database connection error
- Error occurred uring saving, deleting
- Unable to load data from database
Kindly include what kind of exception that would be as well.
My site has been running fine for sometime now until recently I see in the event viewer a null reference exception in the DNN core:
DotNetNuke.Common.Globals.GetStatus() in
F:BuildsMaintenanceWorkingDirectoryLibraryCommonGlobals.vb:line
1125 at DotNetNuke.Common.Initialize.InitializeApp(HttpApplication
app) in
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the line 1125 is:
_Status = UpgradeStatus.None
Which is a property of the Globals class and an Enum Also when this happens it doesnt just do it once then sort its self it does it roughly every minute for an hour or so.I made sure all dataprovider.instances are either in a using or a try catch finally or self closing(if the reader is not used)?
I have the following code, which is meant to loop through a list of CheckBoxes and if checked if gets the text contained in the linked textbox through the tag of the Checkbox, i have used it before and it worked fine but this time i am getting the following error:
Null Reference Exception was unhandled
Dim DisCheckBox As CheckBox() = {chk0_6, chk6_12, chk12_18, chk18_24, chk2_3, chk3_4, chk4_5, chkXSB, chkSB, chkMB, chkLB, chkXLB, chkS, chkM, chkL, chkXL, chkXXL, chkXXXL, chkXXXXL, chkW8, chkW10, chkW12, chkW14, chkW16, chkW18, chkW20}
For Each Chk In DisCheckBox
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