== Versus Object.Equals(object) In .NET?

Sep 22, 2008

when I was a comparitive novice to the novice I am right now, I used to think that these two things were syntactic sugar for each other, ie. that using one over the other was simply a personal preference. Over time, I'm come to find that these two are not the same thing, even in a default implementation (see this and this). To further confuse the matter, each can be overriden/overloaded seperately to have completely different meanings.

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Function - Pass Object Versus Reference Object In Parent?

Dec 1, 2011

I am working on a application that has quite a few functions involved and have been thinking of the following: If I have a function that has a few paramaters, is it more efficient to pass the objects to the function(Example 1) or reference the objects in the parent(Example 2)? Does it matter if the objects are large or not?

Example:

Class mainform
Public myGenericList As New List(Of String)
Public myDatarowArray() As DataRow

[Code].....

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Overriding Equals For An Object With ID

Oct 11, 2011

Is it the best override for Equals (in VB.NET) for an object having an unique ID? [code]I took that example from the MSDN, but not entirely sure if from all points of view (including performance) is the better solution.[code]

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VS 2008 - Suitability Of Referencing Object By ID / Key Versus Instance

Sep 19, 2010

Often I have a list of object A, and I have another object type B that needs to hold a reference to one instance in that list. So, as far as I can imagine, it's three ways to hold such reference:

1. Make B hold the instance variable of type A
2. Make B hold some other key/ID of the A instance
3. Make B hold an integer of the list index of the A instance

I guess 3 is quite limited, and mostly suited for use locally inside a method, in a for-next loop etc. But with the other two I tend to have the feeling that I should use 2) over 1), as I believe I shouldn't "duplicate" the object.. But wonder if that is a mistake. I guess it's only holding a reference to the stack memory, so it doesn't really make any overload compared to holding just an integer key/ID..

Further my thought is that with 1), I don't have to loop through the list to get the correct instance, as it already holds it. However if A changes, it may not be reflected in B.A, if the A has been given a new instance, so then 2) would instead give access to the updated object A. So perhaps if A is a "dynamic" object that may have been reinitialized (if that's a word), I need to use method 2). However if it's a type of object that is only changed when for example the user opens a program settings form, and this setting form only changes value type variables, then perhaps 1) is appropriate?

This is kind of the case I have some times, and I wonder if I should then use 1), as it doesn't require me to loop through the list by key/ID. It makes other object hold the full reference, which is not really necessary, but maybe still more efficient? Although at the same time, maybe I shouldn't really care much about looping through an object list either, if the list is not very big.

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Office Automation :: Excel Object Library 10.0 Versus 11.0 Version?

Jan 6, 2012

I have 2003 xls file which is saved on a web share point. File combines vbs functionalities, of which one is uploading data to this file (from another file on the same share point) by clicking command button.When I open file from my location it all functionalities are working without problems. My customer is running it from his location, he is also using Excel 2003, the moment he wants to upload the data he gets the bug.

Message: Method "Worksheets" of object "_Global" failed

I checked and it seems that in the references he has 10.0 object library and I have 11.0 What i can do to unify the coding so it is indifferent from Object Library version?I have read about late va early binding, I guess i'm using late binding I also check that i can adjust late binding buy standard codes.

Dim oExcel As Object
Dim oWorkbook As Object
Dim oWorksheet As Object

[code]....

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Flattening An Object Hierarchy Using A Shim Class - Initializing Derived Object Properties From The Base Object?

Jul 10, 2010

I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:

newProperty1 - a new string property of the derived class

flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class

Code example:

Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......

Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.

Code example:

' property names are in the string array fieldNames

'baseObjQuery is an ienumerable of baseObj

'derivedObjList is a list of derivedObj[code].....

Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?

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Error - LINQ To Entities Does Not Recognize The Method 'System.Object IIf(Boolean, System.Object, System.Object)'

Jul 29, 2011

I am getting following error whenever I want to use IIf function inside entity framework query.

LINQ to Entities does not recognize the method 'System.Object IIf(Boolean, System.Object, System.Object)' method, and this method cannot be translated into a store expression.

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Method 'System.Object CompareObjectEqual(System.Object, System.Object, Boolean)' Has No Supported Translation To SQL.?

Apr 16, 2010

What do I need to convert?

Dim CEESearchByAppNo = From CEEsearch In dbCEE.tblScanneds _
Where CEEsearch.AppNo = iAppNo

[code].....

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Calculate The Direction An Object Is Facing In Degrees If Object A Is At X1, Y1 And Facing Object B Which Is At X2, Y2?

May 8, 2009

How do I calculate the direction an object is facing in degrees, if object A is at x1, y1 and facing object B which is at x2, y2?

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.net - IEnumerable.Equals Seems To Call The Wrong Equals Method

May 23, 2012

I implemented a PagedModel class to wrap around IEnumerable to provide paging data for grids in my MVC app.I used Resharper's auto-generated Equality code telling it to check the data, total rows, page number, and page size fields.[code]I found the call to Equals(other._ModelData, _ModelData) peculiar, as AFAIK, this checks that it is the same object rather than that the contained items are the same. Because my tests were failing anyways, I went ahead and changed it to other._ModelData.Equals(_ModelData) with no success. Then I reflected into it at debug time and found that other._ ModelData.GetType().GetMethod("Equals",{GetType(Object)}).DeclaringType was Object! Obviously, that would result in the failed comparison.I came up with a solution to create a EnumerableEquals method which compares every item in the two enumerables to confirm the are the same, but it seems sloppy. Is there anything I can do to use the normal .Equals method? [code]

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Exception Found - Cannot Access A Disposed Object. Object Name:'System.Net.Sockets.NetworkStream'

Dec 31, 2009

Occasionally I encountered this exception message while trying to download file from a server using System.Net.FtpWebRequest and System.Net.FtpWebResponse Object.

Download a file.ftpRequest_DL.Method = WebRequestMethods.Ftp.DownloadFile get the response object
Dim ftpResponse_DL As FtpWebResponse = CType(ftpRequest_DL.GetResponse, FtpWebResponse)

[Code]...

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Object Scope - Lose The Object In Selected Date Change Event In Calendar

Oct 18, 2010

If I declare my object at the beggining of my page class, and instantiate it in a dropdownlist selected_index change event. Shouldn't this object be available thru out the entire page and also persist thru a postback? I lose the object in my selected date change event in my calendar.

[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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Create A Global Object But Have The Events Within That Object Fire On A Separate Thread?

Oct 26, 2009

I have an object that is defined as a global variable based on custom class. Within that class I have an event that gets fired a certain intervals. These events are fired on the same thread as where the object is declared. How do I create a global object, but have the events within that object fire on a separate thread?

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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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Format Date In Data Grid View Object Not Set To An Instance Of An Object?

Jan 29, 2012

I'm trying to set the format of a column in a datagridview.When I put the format statement in the on load event for the form, it has no effect. When I put it in the cellformatting event I get the "Object reference not set to an instance of an object" error. I checked the column name. What I am doing wrong?

This is the code:Private Sub MeetingTblDataGridView_CellFormatting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) Handles MeetingTblDataGridView.CellFormatting
Me.MeetingTblDataGridView.Columns("Starttime").DefaultCellStyle.Format = "HH:mm:ss"
End Sub What I'm trying to do is get rid of the date part of a Date/Time field (stored in an Access database) in a datagridview column.

dp.SyntaxHighlighter.ClipboardSwf = '/dp.SyntaxHighlighter/Scripts/clipboard.swf'
dp.SyntaxHighlighter.HighlightAll('09dde30f062e451a854266e66205b1cf')

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Handle An Object's Object Property Changed Event In .NET Windows Forms?

Jun 7, 2012

I know how to handle a single objects property changed event very easily. I want to handle a objects property changed event that is part of another object.

Given Object:

[ObjectY = Y]
+ Public WithEvents X As ObjectX

I would like to do something like:

Private Sub XPropertyChanged() Handles Y.X.PropertyChanged

Right now I need to create a object that equals the object inside that object and then handle this variable pointers property changed, but that is just annoying.

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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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Microsoft Activex Component Can't Create Object While Initializing An Object Of SoapClient30

Jan 12, 2011

I am trying to write an VBA application in Excel 2010 using "Microsoft Soap Toolkit 3.0" on 64 bit Windows 7 to consume an web service. But i got an error while initializing an object of SoapClient30.

Error message is :: Runtime error '429' :ActiveX component can't create object.

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Object Collision - An Object Bounce Back When It Collides With An Rectangle Shape?

Mar 21, 2012

how I could have an object bounce back when it collides with an rectangle shape. There are multiple rectangle shapes and I don't want to do it all seperately for each one.

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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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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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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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