NullReferenceException Was Unhandle When Loop An Object?
Mar 15, 2012
I got two form. form 1 i ask the user a number of guest form 2 i ask each guest their name, their age
i decide to make a loop base on the number of guest but then i got this error. NullReferenceException was unhandled how to solve this...i underline under my code
Private Sub btnBook_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBook.Click iTest = CInt(txtChildren.Text Do Until (iCounter = iTest) And (bIsNextClicked = True) PassengersDetails(iCounter).ShowDialog() Loop End Sub
i have never learn to loop an groupbox or anything so i don't know what wrong but the compiler said "NullReferenceException was unhandle" and here is my code.
iNumberOfPassengers = CInt(txtAdult.Text) gboPassengerDetails.Hide() Dim gboNextPassenger(iNumberOfPassengers) As GroupBox
I am trying to start the process with the following parameters When I try to start it though I get an System.nullreferenceexception: Object reference not set to an instance of an object
Dim exepath As String = Application.StartupPath + "inffmpeg.exe" Dim sr As StreamReader Dim cmd As String = " -i """ + input + """ -ar 22050 -y """ + output + """" Dim ffmpegOutput As String
i am using VB.net 2003 and i am trying to get the number of rows of a dataset from form1 into form2 in order to use it for something else and i am getting the error"System.NullReferenceException occured...Additional information: object reference not set to an instance of an object"...my code is like this:in form1:Public x as integer= me.dataset.table.rows.count here it gives me the error
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).
I am completely new to ASP.NET and VB as well as C#. I am trying to add customers to a contact list out of a DB. Then the list can be referenced to call them up. But when I try to run it I get System.NullReferenceException: Object reference not set to an instance of an object. In line 19.
Here is my code:Page 1 is default page...it connects to the database and grabs the contact information and allows me to select the current contact and add them to a listbox on a separate page:
Imports System.Data Partial Class _Default Inherits System.Web.UI.Page
[code]....
The error occurs on line 19 (For Each customerEntry As DictionaryEntry In Customer) in the second set of code from the default2 class.
I'm finishing up working on the high score list of my Jeopardy game. The only problem that I'm running into is when I try to start from scratch without a textfile in the Debug folder.I get a NullReferenceException was unhandled - Object reference not set to an instance of an object. I get this message with the line If (myPlayers.Length - 1) > 2 Then just before I start to compare the scores and reorder the list by score if necessary.I already declared myPlayers as an array of structures in the beginning of the form.
Private myPlayers() As Players
It writes the name and score to the file, but then gives me that error. My goal is to only fill the file with the three players names and their scores.I figured since the file doesn't exist, I'm doing something in that specific code that effects my reference to myPlayers but I can't figure out what exactly. I tried adding
If (myPlayers.Length - 1) > 2 AND File.Exists("highScore.txt") Then
but its still giving me the error.
'read in scores, add scores to file or create new file if neccessary If File.Exists("highScore.txt") Then Dim InputFile As StreamReader
I am coding in vb.net. At times the data is empty/null this is due to user's input into the db.i will like to bypass it, however i get no luck.here is snippet of my code:
If hct.mydbvalue.name IsNot Nothing Then dr("mydbvalue") = hct.mydbvalue.name End If
I still get an error: System.NullReferenceException: Object reference not set to an instance of an object.is there a way if it is a null value to not do anything?
My login is working fine, but occasionally when I start to run and debug the prog, it will stop running and point to this error. This is my login page
Partial Class Admin Inherits System.Web.UI.MasterPage Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Dim ans As String = Session("Status").ToString()
I have a custom class that all my pages inherit from
Public Class Page : Inherits Page Private Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load 'Display Admin Controls (Buttons) ' If User.Identity.IsAuthenticated Then
[code]....
But for some reason I'm getting this error:
System.NullReferenceException: Object reference not set to an instance of an object.
on this line
If User.Identity.IsAuthenticated Then
This only started happening in IIS7. I have been using this application in IIS6 for over a year without issue, and it's only since I migrated to IIS7 yesterday that this exception started.
i wrote a very simple app and it runs fine on windows xp machines, but on windows 2000 machines... i am getting the following error.. ... nothing showing up in build nor does it happen on xp machines?
************** Exception Text **************System.NullReferenceException: Object reference not set to an instance of an object. at System.Windows.Forms.Control.WaitForWaitHandle(WaitHandle waitHandle) at System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous) at System.Windows.Forms.Control.Invoke(Delegate method, Object[] args) at System.Windows.Forms.Control.Invoke(Delegate method) at
[code]....
When JIT debugging is enabled, any unhandled exceptionwill be sent to the JIT debugger registered on the computerrather than be handled by this dialog box.
I am soooo very new to vb express. i wrote a very simple app and it runs fine on windows xp machines, but on windows 2000 machines. i am getting the following error. nothing showing up in build nor does it happen on xp machines??i have no idea how to fix it!
so I was working on a autoviewer for the site enhanceveiws.net. I have a SmartError Filter in the code. However I got an error. NullReferenceException was unhandled. Object reference not set to an instance of an object. Here is the code.
My codes: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim con As String = "Database=barcouncil;Data Source=dev;UserId=root;password=;" Dim cn As New MySqlConnection Dim da As New MySqlDataAdapter
This is my first ever post in this wonderful forum. I am new to vb.net programming. Given below is a piece of code which throws a system null reference exception at the end of the loop. I am unable to figure out the problem. "drledger" is null at the end of the loop. Even though i am able to catch the exception what can be done to avoid the null reference exception.
Private Sub btnSalesExport_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSalesExport.Click Dim iRowMax As Integer
I got two forms. Form 1 I ask the user a number of guest Form 2 I ask each guest their name, their age
I decide to make a loop throught form2 array base on the number of guest but then I got this error. NullReferenceException was unhandled.
Private Sub btnBook_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBook.Click iTest = CInt(txtChildren.Text) Do Until (iCounter = iTest) And (bIsNextClicked = True) PassengersDetails(iCounter).ShowDialog() Loop End Sub
I'm having problems with Datagridview Column I have a dataset containing a table called Inventory, which i databound to my datagridview.At my form load event, i set one column's backcolor to blue like this-
I'm trying to add objects from a class I created using data from an excel worksheet to a list using a for loop [code]When I run it I receive "System.NullReferenceException was unhandled by user code Message=Object reference not set to an instance of an object."
Actually this application will run on window start up. what i try to do is to delete the file for certain date. I ask the program to delete file if set date equal to now system date... i also ask the program to check if the file is exist or not. If the file is exists. the program run properly but if the file not exists then on windows start up. .NET framework unhandle problem come out [Code]
In an application I am working on I have created a product class which represents an inventory item. I have also created an inventory class which represents a collection of product objects.In the constructor of the Inventory class I load 4 products into a product collection. Each product consists of a code, description price and quantity. Within the form load i would like to add a procedure that loads each products code property into a combo box.Obviously I could do this by hard coding the values but I would like to loop through the collection of products and populate the combo box with the codes contained inside the product collection. This is what I am struggling with. Below is the code for my inventory and product class.
Public Class Product Private sCode As String Private sDescription As String
In an application I am working on I have created a product class which represents an inventory item. I have also created an inventory class which represents a collection of product objects. In the constructor of the Inventory class I load 4 products into a product collection. Each product consists of a code, description price and quantity.
I'm trying to loop through a collection object in vb2010.The code was originally used in Vb6 The book said that I needed to code a NewEnumerator method first in order to be able to loop through my collection. I coded the following:
[code]...
It gives an error for IUnknown, staging that IUnknown is not accessible in this context because it is a 'Friend'.In the line in the function I removed the Set since it's no longer needed.The error message for this line is '_NewEnum' is not a member of 'Microsoft.VisualBasic.Collection'What are these messages and how do I fix this in VB 2010?m_colCourse is not a system collection.
Whenever I try to create a new CD object I get a stack overflow. I want a parameter to be passed into mediaFactory so that it could be determined what type of media is created. Why I might be having problems with this when I do this "Dim media As CD = New CD()" Public MustInherit Class MediaFactory Inherits MediaContext Implements IMedia Public Sub New(ByVal typeId As Integer) [Code] .....
