Use Extension Method On System.Object Instance?
Jul 12, 2010
Can I make an Extension method for all the subclasses of System.Object (everything)?
Example:
<Extension>
Public Function MyExtension(value As Object) As Object
Return value
End Function
The above functions won't work for object instance:UPDATE The problem seems to occur only in VB, where members of object are looked-up by reflection (late-bound).UPDATE AFTER ANSWERED.FYI, as vb has an advantage that C# lacks that is, members of imported Modules are imported to the global scope so you can still use this functions without their wrapper:Dim myObj2 = MyExtension(myObj1)
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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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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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Jun 11, 2009
I have had several occasions recently to access a specific class several times over a relatively small time frame.So I've been storing the value of the class in Session and trying to access it on page load, if it's not available creating a new instance and storing that in session.
So instead of constantly replicating the same code for different classes on different pages I'm trying to create an extension method to do this for me.
[Code]...
I'm stuck on what to do when I make my new instance of my class (it would have to have a New() sub)
I'm not sure where to go from here... or even if this is the best way to do it.
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Mar 11, 2009
following error message:
Method not found: Void Excel.Range.set_Value(System.Object,System.Object)
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Feb 2, 2011
I'm using .NET 3.5 In my DataLayer class I have references of System.Core,System.Data.Linq, System.Data.DataSetExtensions. But I cantnot use this feature in Linq query if I have Option Strict ON:
[Code]...
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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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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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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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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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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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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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Aug 12, 2011
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?
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Dec 14, 2010
Currently working on the status bar for application. I would like the status bar to display message errors if a user makes an invalid entry. I have a module which contains the main procedure and procedures to change the text property of my status bar. A Call is made to the procedures from one of the forms that requires the user input. The application compliles but I get an unhandled exception of type 'System.Null ReferenceException' Object reference not set to an instance of an object. [Code]
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Apr 26, 2011
look after the error i'm having.
module1.vb
Imports System.Data.SqlClient
Module dbconn
[code]....
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Jan 2, 2010
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.
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Dec 4, 2009
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.
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Mar 9, 2009
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!
[Code]...
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Dec 4, 2009
i'm getting this error whenever i run this page.
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
[Code]...
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Nov 19, 2010
Basically, I've got this plugin-based application I've used all the time in VS2008 flawlessly. In my current project (VS2010 by the way) I wrote a plugin for the application and whenever I try to use an instance of a particular class (in an external dll) from my plugin, I get an error.
I tried watching the instance and I got the message:
"Cannot find the method on the object instance."
in the watch window. This has never happened before! I also found that some of the extension methods in the plugin does not work.
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Sep 26, 2010
Use the "new" keyword to create an object instance & Check to determine if the object is null before calling the method. I'm reading text from a text file using the following [Code]
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Jun 13, 2011
I have the following extension method that I've built and have working for one MVC3 project, but when trying to use it in another, the compiler (not the view) gives me the error;Error 1 'TextBoxFor' is not a member of 'System.Web.Mvc.HtmlHelper(Of TModel)'...Intellisense shows none of these html element shorcut methods.I'm sure it's just because I'm missing a reference or something, but beats me what it is.
FImports System.Runtime.CompilerServices
Public Module HtmlHelperExtension
<Extension()> _
[code]...
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Dec 3, 2009
Why would I use an extension method instead of just creating non-extension sub or function?
For ex, I could have an extension function called IsNullOrEmptyOrAllSpaces on String, which does a check as its name implies. Or I can write a stand alone function that does the same thing. Other than having the extension show up in Intellisense, is there any advantage? Is a call to the extension quicker/more efficient than a call to a regular function?
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Mar 16, 2012
I saw this post and I want to know if this is possible in VB. So like extension method, do extension properties exists in VB.Net? Here I've read they do, but cannot find any examples.
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Sep 16, 2010
Write an overload for every numeric type or if possible constrain a generic extension method to just numeric types.
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Jul 28, 2009
I am getting some wierd errors when using the ReportViewer control in Visual Studio 2008. When I try to access the LocalReport property, it displays with this error: "Cannot find the method on the object instance.". Also, I am getting invalid cast errors saying I cannot cast from Microsoft.Reporting.Winforms.ReportViewer to Microsoft.Reporting.Winforms.ReportViewer. I am getting this using either CType or DirectCast. This is really frustrating as I can find almost no documentation on this error.
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Jan 6, 2011
I have an interface ITest with a method GetResult(). I have a class Test which implements ITest and thereby defines private method GetResult().
Next I create an instance of Test in a different class. The code is as below:
Module NewClass
Public Sub New()
Dim i As ITest = New Test()
[Code]....
I am migrating existing code from VB 6 to VB.NET and hence I'm not supposed to change the access modifier of GetResult. Leaving it Private will throw InvalidCastException Unable to cast object of type 'System.Object' to type 'ITest'
Object type variable o is used in many places and hence I don't want to change that. And yes, Test implements ITest.GetMember with a different name.
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Dec 14, 2010
I have tried several versions of this with no luck. The casting of the worksheet works as my data is entered in other parts, but I have a section where I need to add data 1 column right of the cell containing the 'str(0)' value. Most of these parameters are optional. I have even tried the System.Reflection.Missing object.
[Code]...
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May 31, 2011
When I execute the code below I receive the error message: LINQ to Entities does not recognize the method 'System.Object CompareObjectEqual(System.Object, System.Object, Boolean)' method, and this method cannot be translated into a store expression.It seems to be occurring on the line For Each row2 in PCstudent.
[Code]...
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Apr 10, 2012
I know it's a stupid question but I cannot find info about it.
Public Function TestFunc() As String
Dim lMapper = cRouter.StaticPortMappingCollection
Dim lMappedPort As NATUPNPLib.IStaticPortMapping
Dim Test As String
[Code]...
How to get this value? By my way I get *System.__ComObject*
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