Database Binding And Data Navigation Project Error - Null Reference?
Mar 4, 2012
I am trying not to become intimidated or give up.I created a simple database and added stored procedures to read the data on a Windows form using Visual Basic in VS 2010.First I tried the Data Grid Example and all worked, I was able to view the data using a connection string to call the Stored procedure.I have stepped it up a notch by trying to bind data to form controls and I am getting this error message when I try to navigate through the data.
System.NullReferenceException was unhandled
[code].....
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Jul 4, 2010
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.
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Jan 15, 2011
I am basically 4 weeks into my first ever programming class and we are working on a project for the game "Hangman". While I have struggled with everything for the past 3 weeks, I have finally cams across something I have no idea how to correct. I am getting a Null.Reference error in the following line of my
If Not strWordToGuess.Contains(strLetterGuessed) Then
Now this code was provided in my project files, it was dated 4/07, I am currently working in VB 8 express, I am thinking this might have something to do with it.
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Feb 15, 2010
I just tried to convert some of my Projects from VB2008 to VB2010 RC, but got compiling Errors while compiling the resX Files. Seems like the reason are ImageLists/Icons, since if I remove them the files compile fine. I already tried to edit the Forms witch are showing the Errors with the Designer. The Designer changed the Content of the resX file lightly, but the error was still present Here the Error(German Version): 'FormsfrmUserTmpBUTable.resx : error RG0000: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.' I recall a similar error in the Beta, but since I can't find it anymore, I guessed it was fixed.
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Jan 4, 2010
Im trying to write code that will insert 'records' into an xml file, but everytime i click the button to make the changes to the XML file, it throws a null reference exception, ive gone through this code must be 100 times and cannot find what needs to be declared as 'new' as i know nodes can't be 'new' and the doc is 'new'
Imports System.Xml
Public Class frmuseradmin
[code]......
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Sep 18, 2009
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]
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Dec 14, 2009
Public Class Form1
Dim int As Integer = 0
Dim CustomerTable As New DataTable
Dim instance As New InvalidOperationException()
[code].....
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.
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Jun 13, 2012
I know I'm being an idiot here and I just can't work it out. But i'm trying to take some data back from a vb.net database. It's falling over with a Object reference not set to an instance of an object error. And before the code runs it's saying the variable is being used before it's set, but I can't see how. Code:
Private taNotifications As dsDataTableAdapters.NotificationsTableAdapter = New dsDataTableAdapters.NotificationsTableAdapter
Dim notification As dsData.NotificationsDataTable = taNotifications.GetDataByClientID(userrow.UserID)
If notification.Rows.Count > 0 Then
Dim notificationrow As dsData.NotificationsRow
Dim forwardURL As String = notificationrow.ForwardLocation
End If
It falls over on the Dim forwardURL As String = notificationrow.ForwardLocation
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Aug 11, 2010
I have searched for two weeks, every night, exhaustively reading forum threads and trying all suggested solutions no matter how outlandish. Just as is the case with the many many forum threads about this same issue, the site works fine on my development machine. It deploys with no errors. It works from the production server and reads data from the database, but when it attempts to access a profile it crashes with this error.
A number of posts say to check or uncheck an option called "remove app_code.compiled file" but apparently this was a Visual Studio 2005 option. It is nowhere to be found in Visual Studio 2010. A number of posts say to make sure the App_Code.dll is present in my bin directory. It is present. I've deleted the app_code.compile file manually to see if that made any difference. I've changed the target framework from 4.0 to 2.0 and 3.5. I've completely deleted the site in IIS, created a different folder with a different name and redeployed the site with every combination of "allow this precompiled site to be updatable" and "Use fixed naming and single page assemblies".
i've included references to System.Web.Profile and System.Web and System.Web.Profile.ProfileCommon. I've created a new, fresh website targeting .net framework v4.0 and copied that web.config file to my application and recreated my profile entries to ensure that I didn't jack anything up in the config file along the way.
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Jul 8, 2009
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
[code].....
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Mar 1, 2009
am trying to write to a database via a stored procedure. I am trying to save my values to an object and then write to the database. When I click the button to save the record I am getting a null reference.The below is from the frmDMR class.
Public Class frmDMR
Private m_dmrissue As DMRData
Public Property NewDmrIssue() As DMRData
[code]....
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Apr 13, 2011
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]
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Apr 28, 2011
Background: 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
[Code].....
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Jul 23, 2011
I explain what I would do immediately:I have to extract data from a table using html htmlAgility Pack This 'my code that when executed gives me' a reference error.I can not figure out what is wrong, I am more 'I can not do this
a Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
Dim web As New HtmlAgilityPack.HtmlWeb()
Dim doc As New HtmlAgilityPack.HtmlDocument()
doc = web.Load("http://www.mia_pagina")
[Code]...
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Feb 20, 2012
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:-
[Code]...
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Jan 22, 2009
I have a module and form. Module has a structure.
[Code]...
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.
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Apr 24, 2011
when i try to assign data to an array from a text box, i get a null reference exception, stating "Object reference not set to an instance of an object".
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Jun 24, 2010
Im new to VB.net programming and I was wondering on how can I hardcode all of this components. What I'm trying to accomplish is that I want to create my own Binding Navigation along with other components hardcoded so that I can navigate through the DatagridView with my own buttons.. Here is a screenshot
[Code]...
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Jan 12, 2011
I'm using an interop dll in a VB.NET project to get access to some functions in a MFC project.
Dim bIsSupposedToWork As Boolean = True
Dim api As API = GetObject(, "MyProject.API")
[CODE]...
Why?
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Apr 25, 2011
I have 2 projects, one built in VB.NET and another in C#.NET. I want to use certain functionality of VB.NET into C#.NET and hence I have added the dll file of VB.NET solution into C#.NET as a reference by browsing the dll from my system. Say dll name for VB.NET is myData.dll. In my C#.NET project I am trying to declare it as a namespace i.e. "using myData;" and its giving me an error of "Type or namespace name could not be found"
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Sep 16, 2010
I am migrating a project from VS2008 to VS2010 (Framework 4)and I keep getting the following error when trying to use databinding with a child property in VB2010.
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Dec 15, 2011
I 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?
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Aug 1, 2011
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
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Jun 23, 2011
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
[code].....
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Jan 5, 2012
Module Module1
Public Structure structure1
Public TRANS() As structure2
End Structure
Public Structure structure2
Public X() As Integer
End Structure
End Module
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Jun 22, 2010
I can't get past this error in my loop through the data reader specifically dr(12). I tried adding .To String but that doesn't seem to work either. Can someone help me with what need to do so it can read even if there is a Null value. My code is below:
While objDataReader.Read()
'Set up DataRow object
Dim dr As DataRow = DataReaderTable.NewRow
[code].....
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Jan 12, 2009
I am trying to make a small application and I have a problem in binding data after filtering them.I use VB 2005 and SQL 2005. The data are shown in datagridview and I bind the selected row to the text boxes of the form. eg.[code]Later on I search the data for some records and at the same time I remove the databinding. When I try to bind them again it does not work because the index is from the whole data and not the filter data.I have fixed the problem in another situation where I had autonumberin as a primary key and I used this as an index. In this case I use platesno as an index and it's not working.
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Jan 20, 2012
I am trying to extract a hyperlink using the open file dialog with no success.System.NullReferenceExceptionObject reference not set to an instance of an object.
at DPR_Library_5.FormCode.CTRL177_5_Clicked(Object sender, ClickedEventArgs e) in \srv-na01user
epInfoPathProjectsDPR_Library_Final_1_GetFileFormCode.vb:line 76
[code]....
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Feb 4, 2012
I am trying to load an image onto a web form depending on the image's URL path inside a database. I can get this to work, however I am trying to display a dummy image incase the record in the database has no image and the column is NULL.
Below is the code that I imagined would work but I receive an error:
Conversion from type 'DBNull' to type 'String' is not valid.
'// Load Item Image in imgMenuItem Image Control //
If (Not IsDBNull(Rdr("img_url"))) Then
imgMenuItem.ImageUrl = Rdr("img_url")
[Code].....
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Apr 25, 2009
I developed an application with old VB form and binding the data from Oracle database into VB form. Actually, I tried to bind the data more than 35000 records in to grid. But, it takes more than half an hour and also form was hanged and there is no output. Can you please let me know the solution to fix it and bind the data without any hang in my application. What are the steps to be followed to fix it?
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