I 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]...
Function 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
I'm trying to make a simple equalizer I have my windows media control and a trackbar, this is the code im using.
Private Sub TBGLevel_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TBGLevel.Scroll
Dim equalizer As WMPLib.IWMPEqualizerSettingsCtrl
equalizer.gainLevel1 = TBGLevel.Value
End Sub
Upon moving the trackbar I get this error
NullReferenceException was unhandled Object reference not set to an instance of an object.
I also tried
Public equalizer As WMPLib.IWMPEqualizerSettingsCtrl
Same error occured.Basically i hit play so it would go through my playlist on the form then attempted to move that gainlevel and it produced the error.
i have a code that grabs an image from a site, this works fine and it does get the image fine, but every now and again my internet runs slow and it takes a while for the image to pop up thus causing the error:[code]How would i make it display the msgbox if it returns NullReferenceException error ?
View 9 Repliesi have a small problem with my code that only happens every now and again.Im using multi threading on this and every now and again i get this error: System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object."
Some times the program completes perfect with no errors and sometimes i get the above error.When i get the error there is always 1 item left in the list but when it completes perfect no items are left.Again this error does not appear every time, only every now and again. For example i had to run my program like 20 time to get this error, 19 times it worked perfect with no errors and 1 time with this error.
I have 5 columns in my datagridview, I want the ability to hide them, depending on which checkboxes are ticked (I have 4 checkboxes). This can either be as soon as the checkbox changes state or after a button is clicked to reload the dataset/gridview.
View 3 Replies[code] this is my code n i want to store data at runtime in the my database.i used data base as an access07 and my platform is vb.net..Now come to the point when i run the project it terminates when i'm inserting my data in the access file.[code]
View 4 RepliesMy code
Dim pointer As Integer, index As Integer
For pointer = 1 To 6
For index = 0 To 5999
[CODE]...
All i get is an error message saying NullReferenceException was unhandled the bold part is were it says the error is
I have recently gotten my hands on a free, open-source IMAP connection API.So far, I have been successful in creating a connection to one of my accounts.Where I'm getting stuck is retrieving folders and/or emails from those folders.Does there happen to be anyone here that is familiar with this API, or even Gmail (particularly the folder structure for IMAP)?
If not, here is a link to the DLL that is listed on sourceforge and the company's website that created it (if you feel like testing):
Koolwired
Sourceforge - Koolwired API
I have created a test account so feel free to use the code below without worrying about username/password issues; I'll just delete it when I'm done with it.Here is the code I have made so far for making a connection:
Dim gSession As New Koolwired.Imap.ImapConnect("imap.gmail.com", 993, True)
Dim gAuthenticate As New Koolwired.Imap.ImapAuthenticate(gSession, "imap_test@serysoft.com", "imap_test")
Try
[code]....
When I run that code, I get an error that states:System.NullReferenceException: Object reference not sent to an instance of an object. (The bold line in the above code).
Now, I'm not sure exactly what that means. Does that mean it tried to access the server and "INBOX" doesn't exist so it gets returned a NULL value? Or is it possibly the coding itself?Maybe the Gmail folder system is weird due to the fact they use labels (even though from what I have read online, the labels act as the folders in the IMAP system).
look after the error i'm having.
module1.vb
Imports System.Data.SqlClient
Module dbconn
[code]....
I 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))
View 7 RepliesThis 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.
When 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?
How 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...
Okay 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].....
I 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.
I'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]....
vb
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.)
This 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]...
VB
Dimserial As New Processserial.StartInfo.FileName = "adb"serial.StartInfo.Arguments = "get-serialno"serial.StartInfo.UseShellExecute = Falseserial.StartInfo.RedirectStandardOutput =
[code].....
I'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?
I 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
I 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?
The 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.
I 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?
As 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]......
We 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).
I 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))
I 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?
I'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()