Does An Object Retrieved From A List Get A Copy Of That Object Or A Reference To It

Feb 1, 2012

In VB.net, when I retrieve a value from a list do I get a copy of that value or a reference to it?

dim blah as someObject
dim listOfBlahs as list(of someObject)
listOfBlah.add(new someObject(1))

[Code]....

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Asp.net Mvc - Creating A List (of String) Giving Error" Object Reference Not Set To An Instance Of An Object"

Nov 1, 2011

MVC 3 razor VB.NET project. I have resorted to manual building a list for a drop down box so I can insure certain values are available in the select list and also to control what the first item is in the list. The below is my code snippet for the part that is giving me problems..

[Code]...

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VS 2010 "Object Reference" Error When Adding Object To List (Of T) Property

Apr 25, 2011

I have a class that has a property that I declare like this:

VB.NET
Private _DirectoryList As List(Of FileDirectoryInfo) ''' <summary> ''' Array of directories. ''' </summary> ''' <value>Object</value> ''' <returns>Directory array list</returns> ''' <remarks>N/A</remarks> Public Property Directory As List(Of FileDirectoryInfo) Get Return _DirectoryList End Get Set(ByVal value As List(Of FileDirectoryInfo)) _DirectoryList = value End Set End Property

[Code]...

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Add Object To Collection (copy Not Reference)?

Mar 27, 2009

i have a user define object which i'm initializing with data from external datafiles.... the purpose of this object is to reduce the amount of disk/data access and processing required every time i need to add an instance of this object to a collection.so, whenever i add a copy of this object to a collection, i would simply reference the "base" object, and avoid having to process all the data and perform the conversion and so on...the issue is when i add the object

Collection.add(Base_Object, Key)

the collection ITEM is a Reference to the base object and not a copy.

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Deep Copy - Is Object Returned By Reference From Function ?

Aug 5, 2011

If I instantiate an object within a function in VB.NET and return it, does it return it be reference or by value. IE - should I be worried about performance if I write something like this:

Public Function ret_obj_func() As big_object
Dim ret_obj As New big_obj(<lots of stuff>)
Return ret_obj
End Function

If I call this function from somewhere else, will it instantiate the object in the ret_obj and then create a deep copy to pass back a copy to the caller, Or will it just pass back a reference?

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.net - "Object Reference Not Set To An Instance Of An Object" Trying To Add To List?

Dec 19, 2011

I've created A list of object "emails" which contains the "email" object which has 3 parameters (String Address, String Subject, String Body)I then want to add to the list by creating more instances of "email". However, I've tried so many different ways and it's having none of it.

Public Class Test
Public emails As List(Of Email)

[code].....

If I click button1 I get the error "Object reference not set to an instance of an object".

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Copy List Object To Another List Object

Jun 15, 2012

I am having a problem when setting VB.NET list object to another.I create an instance on ReadLocations and than create an object of ReadLocation where then I loop through ReadLocations and set ReadLocation1 equal to rl. What happens is that if I then go and change ReadLocation1 to something else (assdfhsd) it will also change the ReadLocations index. I am really confused why it would be doing that unless it is "=" sign means referencing instead of actually setting the value. Please help as I am a C# developer but the program I am modifying is in VB.NET.[code]

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Object Reference Error "Object Reference Not Set To An Instance Of An Object"?

Aug 26, 2011

I have this bit of code

Private Sub SpellChkMenuItem_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles SpellChkMenuItem.Click
Dim activeRichTextBox = TryCast(Me.ActiveControl, RichTextBox)
'clsFS.CheckSpelling(activeRichTextBox)[code]....

When I am in the rtb and click on spell check button it tells me the error "Object reference not set to an instance of an object." On this line

SpellChecker.Text = activeRichTextBox.Text

But it is suppose to be getting the focused rtb correct? So why is it not referenced

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Use Retrieved Table Values As Object Names?

May 2, 2012

I've Created a Table in my Database "T_OPTIONS"

my table looks like this.[code]...

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Very Simple Ssis Script Transformation Giving Object Reference Not Set To An Instance Of An Object

Mar 1, 2012

I have an ssis package that takes a flat file and dumps it to SQL. During that process, 150 columns need to have '-' and '.' removed from them. I have done this using a Script Transformation.

Public Overrides Sub Input0_ProcessInputRow(ByVal Row As Input0Buffer)
Dim column As IDTSInputColumn90
Dim rowType As Type = Row.GetType()

[code]....

Edit I've discovered that this line is the problem

Dim strCol As String = columnValue.GetValue(Row, Nothing).ToString()

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.net - Process.start System.nullreferenceexception: Object Reference Not Set To An Instance Of An Object

Oct 16, 2011

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

[code]....

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Asp.net - Checking For A Session Variable... Returns (Object Reference Not Set To An Instance Of An Object)

Jan 12, 2011

In the Session_Start of the Global.asax i have

Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
Session("login") = False

[code]....

Why i am getting error the error Object reference not set to an instance of an object. at line

If Current.Session("login") Is Nothing Then

while checking for the login state as follows?

If GetLogin = False Then
'Do something
End if

I mean i have already created the instance on the Session_Start... Haven't i?

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Error System.NullReferenceException Occurred - Object Reference Not Set To An Instance Of An Object

Jan 12, 2010

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

in form2:
dim frm as new form1
msgbox(frm.x)

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Error: System.NullReference Exception: Object Reference Not Set To An Instance Of An Object

Jan 5, 2010

I am getting this error when I try to print my report. Here is my print code.

Private Sub PrintToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PrintToolStripMenuItem.Click
Dim Print_Dialog As New PrintDialog

[code].....

Here is my error: System.NullReference Exception: Object reference not set to an instance of an object.

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Line Of Code Is Generating This Error - Object Reference Not Set To An Instance Of An Object?

Aug 14, 2010

with datagridview1

while looping through all the cells

i am trying to allot a cell value to another cell value basing on some conditions
& finally delete one column.my code is as fallows

Dim i, x As Integer
i = 0
x = Me.DataGridView1.Rows.Count[code]....

error i am getting is : Object reference not set to an instance of an object.it is extremely surprising for me the same code has worked nice for me but why & how the same line of code is generating this error.

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Object Reference Not Set To An Instance Of An Object When Searching For User In Active Directory?

May 8, 2012

I tryed searching for an user in active directory using the code below but it gives me the error in the title of this post above:

AD = New DirectoryEntry("LDAP://OU=SchoolOUhere,OU=Staff,DC=garrard,DC=ketsds,DC=net", "", "", AuthenticationTypes.Secure)
AD2 = New DirectoryEntry("LDAP://OU=_Groups,OU=Staff,DC=garrard,DC=ketsds,DC=net", "", "", AuthenticationTypes.Secure)

[Code]...

Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. - "Sherlock holmes" "speak softly and carry a big stick" - theodore roosevelt. Fear leads to anger, anger leads to hate, hate leads to[URL]...

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Object Reference Not Set To An Instance Of An Object With A Class With An Array Of Classes As A Member?

Aug 6, 2010

Here is the structure that I have:

Friend Class StandardFormatFile
Friend fileType As String
Friend numberOfSeries As Integer

[code].....

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VS 2008 - Error With Arraylist In My.Settings - Object Reference Not Set To An Instance Of An Object

Mar 14, 2010

The issue is when I try to add a new item to the ArrayList with the following code, it gives me an error:

vb Private Sub btnLabelAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLabelAdd.Click
Dim result As String = InputBox("New Filter Label:", "Label List")

[CODE]................

Object reference not set to an instance of an object.

I'm not really sure what I'm supposed to be doing with this. It's a new setting I just added and it's empty, so I'm not sure if that has anything to do with it or not. Anyone know what's going on and what needs to be done to get it to accept a value and not want to be "initialized"?

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VS 2008 Error - System.NullReferenceException: Object Reference Not Sent To An Instance Of An Object

Oct 23, 2009

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).

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List Of T Find Date Or Other Property In A Object In The List - Then Return Found Object?

Sep 3, 2009

After reading all the examples for list of T exists and Find and find first, none show how to handle multi-property objects. Below is bare bones example maybe someone could flesh out to show how this should be done.

Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim DatePriceList As New List(Of DateAndPrice)
DatePriceList.Add(New DateAndPrice(Date.Parse("1/1/2000"), 10.12))
DatePriceList.Add(New DateAndPrice(Date.Parse("1/2/2000"), 11.12))

[Code]...

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Failure To Create Data Controls To Access Database Object Reference Not Set To An Instance Of An Object?

May 3, 2011

I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"

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Fill_Text Code Throws An Error : System.NullReferenceException:Object Reference Not Set To An Instance Of An Object

Apr 18, 2010

I got the following code from the demo code samples and just changed the textbox names. But it throws an error:

Private Sub Fill_TextBox()
Dim Num As Integer
Dim DSet As DataSet

[code]....

The error is:

System.NullReferenceException:Object reference not set to an instance of an object.

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Cast A Reference To An Object To A Reference To An Object Of The Same Class?

Mar 17, 2012

The book "Beginning ASP .NET 4 in VB 2010" contains the following:NOTE: TaxableProduct inherits from Product.You can also cast in the reverse directionfor example, cast a Productreference to a TaxableProduct reference. The trick here is that this

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Event Handler Code Cause A Object Reference Not Set To An Instance Of An Object. Error (only Present On Live Server, Ok On Dev)?

Mar 4, 2010

Here is the code for the button click event;

Protected Sub CompetenciesButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles CompetenciesButton.Click
Dim con As String = WebConfigurationManager.ConnectionStrings("foo").ToString()

[code].....

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'Object Reference Not Set To Instance Of An Object' While Creating Pivot In Excel

Jun 23, 2012

I'm trying to create a pivot table by opening an Excel file from my drive.But I'm receiving the error saying "Object reference not set to an instance of an object".[code]

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.net - Getting An ASP.NET Error System.NullReferenceException: Object Reference Not Set To An Instance Of An Object?

Oct 30, 2011

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.

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Application - Getting An Error Stating Object Reference Not Set To An Instance Of An Object

May 2, 2010

I am making an application that takes information from the textboxes and saves it to a sequential access file or text file named checkfile.txt. I have the textfile in the proper location within the project folder.

I am getting an error stating Object reference not set to an instance of an object.

And this part of the code is highlighted

CODE:

Here's the code:

CODE:

Attached image(s)

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Asp.net - Nested Repeater Error: Object Reference Not Set To An Instance Of An Object?

Jul 28, 2011

I am taking some code that I have used for a nested listview before and trying to make it work with a nested Repeater but I am getting an error.

System.NullReferenceException: Object reference not set to an instance of an object.

.aspx
<asp:Repeater ID="reMainNav" runat="server">
<HeaderTemplate><ul></HeaderTemplate>[code].....

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Error - Creating The Form - Object Reference Not Set To An Instance Of An Object

Apr 13, 2012

I'm having this problem with my code and cannot seem to get past it although it was working fine before. The error is "An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object." The code is:

CODE:

I am trying to get information to be pulled out of a database and show in text boxes on another form (frmviewsdets). The error occurs when it gets to the line frmviewsdets.txtsnumber.Text = rdr("StudentNumber") and even when a breakpoint is applied there it just moves on to the next and so on.

I have tried to show frmviewsdets before I pull the data out of the database beut I get the same message.

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Error - NullReferenceException Was Unhandled - Object Reference Not Set To An Instance Of An Object

Apr 15, 2009

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

[code]....

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