NullReferenceException In VB?
Oct 21, 2010I am getting a NullReferenceException was unhandled error when i run my debugging in this part of my code:Dim x As Integer = Val(index.Chars(0))
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.NET - NullReferenceException Unhandled?
Sep 19, 2011This never happened to me, and the less data one has (usually) the less you can say what happened.I am trying to write a simple query analyser. I randomly receive these kind of crashes:
[Code]...
The file specified above does not exist. The place where it crashes is wrapped with Try-End Try. Moreover, yes, I have the painting event set up but it should not concern it (or maybe it does?). I have to add that I use visual basic express edition. The error occurs ocasionally - sometimes when I'm lucky nothing happens, and when I'm not then I get this crash.
Catching NullReferenceException?
Apr 5, 2011When I debug a program my IDE simply does not catch System.NullReferenceException - execution continues as if there were nothing wrong.Moreover, when I go to the menu Debug/Exceptions System.NullReferenceException is not even in the list(Common Language Runtime Exceptions).
I manually add it (there is the Add button) and I put a checkmark in the 'Thrown' and 'User unhandled' column - now IDE catches it, but after I re-load the project the situation re-appears - and NullReferenceException is not on the list again. What may be wrong?
Update:No, when I step through the code the execution does not continue but exits the current block of code (sub or function). There were no Try...Catch blocks and there is a message: A System.NullReferenceException occured in MSCorlib.dll... But why doesn't the debugger stop at this line?
Get A NullReferenceException In The Following Scenario?
Jun 8, 2010How can I get a NullReferenceException in the following scenario?
Dim langs As IEnumerable(Of SomeCustomObject) = //some LINQ query
If langs Is Nothing Then Return Nothing
If langs.Count = 1 Then //NullReferenceException here
What am I missing here? Debug shows that langs is really just a LINQ queryresult without any results...
NullReferenceException Error?
Nov 21, 2009Okay after searching two listbox's on a form I am trying to put a number as a string in a label setup for that but keep exgetting a NullReferenceexception error on the label. Label being "shippingDataLabel.text".e is my code;
Public Class MainForm
Dim fifteenShipping As Integer = 15
Dim twentyShipping As Integer = 20
[code].....
NullReferenceException In .NET After Upgrade To 4.0?
Jul 25, 2011I have a VB.NET solution that I just upgraded. It was originally in .NET 1.1, I upgraded to .NET 2.0 and verified that it would build and run correctly. Then I upgraded from 2.0 to 4.0. It is still building with no errors, but when I try to run I am getting a NullReferenceException in Global.asax.vb. The really weird thing is, the line that is throwing the exception is this:
Dim dt As System.Data.DataTable I am not trying to use the variable, just declare it. Further down a Function is called that returns a DataTable and sets the variable, but I don't even get to that line. It is throwing the NullReferenceException on the Dim line. Has anyone run across this before? Is this some issue with upgrading?
[Code]...
I did a Rebuild Solution before posting. This is a web application and the only files I see in the bin folder are the dll files I am referencing. I'm not sure what else I should clean up.
NullReferenceException VB2005?
Mar 16, 2009I've seen so many posts on this but I just don't understand how to fix it.
HTML
Me.txtDeletedItem.Text = objDeleteLog.Name
[b]Me.txtDeleteReason.Text = objDeleteLog.Code.Description[/b]
[code]....
NullReferenceException Was Unhandled
Jan 25, 2012vb
Imports System.Windows.Forms.HtmlDocument
Public Class test_vbdotnet
Private Sub runtime()
[Code].....
I want VB.NET to get access to the innerText and make a if statement out of it. But it always returns error. (see the comments for details.)
NullReferenceException Was Unhandled?
Nov 30, 2010This is driving me slighty madder than i usually am. The thing thats bugging me is the EXACT same code works in a test project i did with an sdf database.See my comments in the code
vb Private Sub tbScan_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles tbScan.KeyUp
[Code]...
NullReferenceException With String?
May 7, 2011VB
Dimserial As New Processserial.StartInfo.FileName = "adb"serial.StartInfo.Arguments = "get-serialno"serial.StartInfo.UseShellExecute = Falseserial.StartInfo.RedirectStandardOutput =
[code].....
System.NullReferenceException
Feb 24, 2010I've got a little problem here:
Code:
Dim DirInfo As IO.DirectoryInfo = Nothing
... some code ...
Me.Tag = DirInfo.FullName
In this code, DirInfo.FullName is sometimes null. So I put this code inside a Try Catch. Although it works fine but I see a System.NullReferenceException in Immediate Windows. I just want to prevent it.
So tried:
If DirInfo.FullName IsNot Nothing Then Me.Tag = DirInfo.FullName
If DirInfo.FullName <> Nothing Then Me.Tag = DirInfo.FullName
If DirInfo.FullName <> "" Then Me.Tag = DirInfo.FullName
But I still get this System.NullReferenceException! How should I check DirInfo.FullName so I prevent this exception?
UNZIP NullReferenceException?
May 12, 2009I keep getting a NullReferenceException error on this UNZIP code:
Dim Sh As New Shell
Dim SF As Folder = Sh.NameSpace("C:\test.zip")
Dim DF As Folder = Sh.NameSpace("C:\test")
[Code]....
i checked to see if i had a test.zip file in my root dir...its there... i have shell32 referenced
.net - ConvertAll Fails With NullReferenceException?
Jul 21, 2011I am trying to flatten a multi-dimensional array with ConvertAll but I can't get it to work:
Private Function Flatten(ByRef a As Object) As Object
Dim elements As Integer = 0
Dim size As Integer[code]...
Why does it throw NullReferenceException?
.net - Process.WaitForExit() Causes A NullReferenceException
May 18, 2009The following code causes a NullReferenceException
tStartParameter = String.Format(tStartParameter, tTo, tSubject)
tProcess = Process.Start(New ProcessStartInfo(tStartParameter) _
With {.UseShellExecute = True})
tProcess.WaitForExit()
[Code]....
causes this exception:
InvalidOperationException: No process is associated with this object.
Asp.net - NullReferenceException Even After Checking With IsDBNull
May 22, 2012I have the following code:
Dim getProspect = (From p In dbContext.IRF_Prospects _
Where p.url = prospect_url _
Select p).FirstOrDefault
[Code]....
When I execute it, it throws an object reference not set to an instance of an object error on getProspect.user_id. Why is it doing this? Shouldn't the fact that I'm verifying it exists using IsDBNull first keep this from happening?
Asp.net - NullReferenceException On Web User Control
Oct 28, 2010As a test, my boss asked me to convert a (not very critical) ASP.NET site from 1.1 to 4.0. Well, it's not extremely difficult and things are going well so far. However, I've hit a small snag. I keep getting a NullReferenceException when I run this code:
Public Property PageTitle() As String
'===========================================================================
'Exposes the PageTitle property of the child control.
[Code]......
Catch NullReferenceException Or Test For Nothing First?
Nov 12, 2010We have a property whose job is to look up a description. If the lookup fails it should show an empty string.
So we can code the property like this:
If foo.bar Is Not Nothing Then
Return foo.bar.Description
Else
[Code]....
But are there any problems (performance, purity, other?) with just catching and ignoring the error?
You sometimes read it's expensive to throw an exception but I am not sure whether the author means it's expensive to build in exceptions using the Throw keyword (which I am not doing) or whether he means it's expensive to allow exceptions to occur (as I would be doing).
Error - NullReferenceException Was Unhandled
Jun 3, 2009I have made a tic tac toe board and when i go to debug the application i get a "NullReferenceException was unhandled".
this happens diring this part of the code:
Dim x As Integer = Val(index.Chars(0))
Getting A NullReferenceException Was Unhandled Error
Jun 3, 2009I am getting a NullReferenceException was unhandled error when i run my debugging in this part of my code: Dim x As Integer = Val(index.Chars(0))
what can i do so this will stop and my program will work?
NullReferenceException Error In VB Application?
Apr 11, 2011I'm building a voting system for calls, and have tried to build it in VB. So far this is what I have:
Dim con As New OleDb.OleDbConnection
Dim dbProvider As String
Dim dbSource As String
[code]....
This code is contained within a "Record Call" button. On the form, there are four radio buttons, all with different text values which should be entered in to the "voting" table.My problem is that when I select a radio button and click on "Record Button" it then displays this error:
NullReferenceException: Object reference not set to an instance of an object.
This error is displayed on the line
dsNewRow = ds.Tables("voting").NewRow()
NullReferenceException For A Class Array
Mar 23, 2010I'm pretty new to VB.NET (VS 2008) so I apologize in advance if my problem is very basic.
I have defined several public arrays with fixed dimension is a public class:
Code:
Now in the main class I'm declaring two global variables:
Code:
I can then redim "parent2.V()" without problem.
Everything works fine with "parent1" but "parent2" gives me a NullReferenceException when I try to read/write from it. Troubleshooting tips tell me "Use the 'new' keyword to create an object instance" which is what I did. How to declare that array "parent2"?
NullReferenceException Unhandled For Combobox1?
Dec 10, 2010on Form1, i have a combobox1 where i have 15 values. im using a case statement with those 15 values to decide what is the next form to go to. i need to make sure the user cannot add in his own text to it or click the NEXT button without having any value at all. how do i add these "exceptions" to my code?
i would think any exception would go before the case so that it could tell you didnt put in the right answer before it looks through the case statment and give you a nullexceptionhandler reference.
NullReferenceException When DataGridViewComboBoxCell Is Clicked?
Jan 19, 2012I get the following error message when entering edit mode on a DataGridViewComboBoxCell:
System.NullReferenceException was unhandled Message=Object reference not set to an instance of an object.
Source=System.Windows.Forms
StackTrace:
[Code]...
NullReferenceException With ToolTip.CreateHandle?
Jun 18, 2010We sporadically get errors when we try to update a tool tip, like thisToolTip.SetToolTip(myLabel, customDataStructure)The error we get is a NullReferenceException: Object reference not set to an instance of an objectDoes anyone know the cause of this?Is a simple Try/Catch that eats the NullReferenceException a feasible option? We don't want our entire application to blow up when we get this.
View 9 RepliesVS 2005 NullReferenceException Was Unhandled
Aug 20, 2010I am working on my project with the listbox, I am reading the strings through the text file and split the strings to input them on the listbox.[code]When I selected the item on the listbox, I get the error.Error: Object variable or With block variable not set.
View 11 RepliesVS 2008 DataGridViewPrinter NullReferenceException?
Oct 8, 2009I get this error message: Object reference not set to an instance of an object at the bolded line of this
Public Sub MyPrintDocument_PrintPage(ByVal sender As Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles myprintdocument.PrintPage
Dim more As New Boolean
more = mydatagridviewprinter.DrawDataGridView(e.Graphics)
If more Then e.HasMorePages = True
End Sub
Here is DrawDataGridView:
[Code]...
VS 2008 System.NullReferenceException?
Nov 25, 2009Function GetHtml(ByVal url As String, ByRef web As WebBrowser) As String
Dim WebString As String
Dim myURI As New Uri(url)
web.Url = myURI
WebString = web.Document.Body.InnerHtml
Return WebString
End Function
System.NullReferenceException
.net - NullReferenceException Unit Testing Error
Sep 18, 2011Doing some homework on unit testing and in all honestly i just don't get why i get this error.
i got a simple method that select all text when tab and testing if the actually textbox1 is selected. I just don't get why i'm getting a nullReferenceException at target.txtbox1_Enter(sender, e)
Private Sub txtbox1_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtbox1.enter
Dim txtBox As TextBox
[Code].....
.net - Visual Basic: NullReferenceException Was Unhandled?
Nov 9, 2011I can't work out what's causing it. The error report says "Object variable or With block variable not set." for the line "allSlotLabels(i).Image = imgCherries". This line is no different from the other, so I guess it's just the error it picked up first after randomly generating the number.
[Code]...
Adding Row To Database And Get NullReferenceException Was Unhandled?
Sep 6, 2009Using Visual Basic 2008 Express Edition, and trying to set up code for an Add button to add a row to an SQL database. The code below is copied from the Help, and modified to reflect the fact my dataset is called Test_SQL_DbDataSet, my table is called Details, and just 2 columns at the moment .. "ID" and "Detail"
Dim newDetailsRow As DataRow = Test_SQL_DbDataSet.Tables("Details").NewRow()
newDetailsRow("ID") = "10"
newDetailsRow("Detail") = "Maint"
Test_SQL_DbDataSet.Tables("Details").Rows.Add(newDetailsRow)
When I select it, I get a "NullReferenceException was unhandled" error saying "Object reference not set to an instance of an object"