VS 2010 List(of Class) - System.NullReferenceException Error When Add The Info To The List
Jan 27, 2011I'm getting System.NullReferenceException error when I try to add the employee info to the Employees list.
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NullReferenceException Error Adding Object To A List
Jun 20, 2012I'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."
View 4 RepliesGetting Error In Code As Initially Array List Is Null / NullReferenceException Was Unhandled
Oct 19, 2009The code below is used to check if the application setting, an arraylist is populated or not via the count method.
When running the program fails with error "NullReferenceException was unhandled" as initially the setting (arraylist) will contain no values.In similar circumstances I would declare a new instance of the object or set value to string.empty or check if DBNull.
I know application settings have a save method but to reference/load them one is not needed.I also left the value field in the projects -> settings to be empty.[code]...
Error - Red "List" Says Too Few Type Arguments To System.Collections.Generic.List(Of T)'
Mar 12, 2009I have converted c# .cs to vb:= I have 6 errors on:
Red "List" says Too few type arguments to system.Collections.Generic.List(Of T)'
Orange "Calendar" says Value of type 'System.Windows.Forms.Control.ControlCollection' cannot be converted to 'Form1.Kobush.Windows.Forms.Appointment'.
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VS 2010 Find Info NOT In A List Using LINQ?
Sep 20, 2011For a class project I am supposed to search through the attached file, and write to a new file the years between 1789 and 2009 that are not present in the fifth field. What is my best bet for determining what years are not present?
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Should I make an array of integer between 1789 and 2009, then search for every year in the file, then set a flag to false if not found; is there a simpler way to accomplish this using LINQ?
VS 2010 How To Import Info From A DB To A Listbox While Crossreferencing Another List Box
Aug 3, 2011So I have a program that is supposed to support a small business. I have the work completed and the professor said it was correct but I wanted to go do a little extra.Basically, on the Order screen, you begin to type the name of a customer/supplier/employee into a text box and a list of names that fit the criteria pops up in a list box (lbMatchingAccounts). When you select it, you can hit enter new order and be transported to the Order Details screen to enter the new order.
What I wanted to do was to create a new list box (lbOrderId). What I want is to be able to select a person from lbMatchingAccounts and have all their Orders populate in lbOrderId.
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Passing A System.Collections.Generic.List To Another Class?
Jun 10, 2012I am trying to pass a System.Collections.Generic.List to another class. The collection is created in class2 and then passed into class1
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However I get a 'Null Reference Exception error' when I run the program. It seems f_str in the line 'For Each s As String In f_str' is null.
VS 2010 : Create A New Class And Have Each List Item Of That Class Such As 'btnID', 'btnText'?
Apr 27, 2011I want to read a number of items from a file and then associate each of those items with a new button at run-time, so that when the user clicks one of the buttons I can display some information about that item.Can I use a LIST to manage these buttons and items? Can I create a new class and have each list item of that class, such as 'btnID', 'btnText', etc... ?
View 2 RepliesGet Type Of Derived Generic List Class From List Item Method?
Mar 23, 2011Public Class notifierMain
Public Class Contacts
Inherits List(Of row)
Public Sub New()
[code]....
When I debug this winforms application I get curType = "notifier.notifierMain+Contacts+row" I want to the Validate function to know it is in MyContacts. How do I do this?
Make A Project Where A Teacher Views A List Box With A List Of Students Of A Class?
Nov 5, 2011I wish to make a project where a teacher views a list box with a list of students of a class. When he selects a name from the first list box the second listbox would change its data to show the grades for that one student.
View 10 Replies.net - Returning A List Using Entity Framework, 'System.Collections.Generic.List Cannot Be Converted To '1-dimensional Array
May 3, 2012i have issue returning a list in a web method. here is the code
<WebMethod()> _
Public Function getTags(para_parents As String) As List(Of getTypeDetailsByParentName_Result)()
Dim context As New PPEntities
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the error is
Value of type 'System.Collections.Generic.List(Of SaftyonRoad.getTypeDetailsByParentName_Result)' cannot be converted to '1-dimensional array of System.Collections.Generic.List(Of SaftyonRoad.getTypeDetailsByParentName_Result)'
Convert A List Linq Expression To Defined List Class?
May 26, 2012y have this class
Private Class MyClass
Public Property propertyOne() as String
Public Property propertyTwo() as String
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Using The List Class - Displaying Information From A List Into A Listbox
Mar 6, 2012I am trying to understand classes in VB 2010. I am a bit confused with displaying information from a list into a listbox.When I run the following code, the word collection appears in my list box. How do I drill down into 'hostnames' to display the info I want.
Public Class computer
Private _HostName As String
Public Property HostName As String
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NullReferenceException While Reading The Description Of The Event Log Using System.Management Class?
Jan 25, 2011I am able to query/read the event log using VB.NET 2005 (Win XP). But still I have a problem reading the "Message" / "description" of the event log.I am getting a System.NullReferenceException while reading the "Message" / "Description" of the event log.Also when I use System.Diagnostics.EventLog and read all the Event on by one I am able to read the message/description of the event. This is the code:
Public Sub ReadEvent()
Dim iCount As Int16
Dim PastFourHours As Date = Date.Now.AddHours(-4)[code]......
C# - WCF Serialization And Interfaces - Error: List(of Object) Cannot Be Converted To List(of IMyInterface)
Oct 16, 2009Does link text mean I have to return a concrete implementation? Even though I am using svcutil with the /r that includes my entites(where IMyInterface is defined). I get no errors but it changes all List(of IMyInterface) to list(of Object) and I cannot deserialize it on the client
Error: list(of object) cannot be converted to list(of IMyInterface).
VS 2010 Checking A List (Of Class) For An Element
Dec 15, 2010[code]Now how can I check if a certain employee is in the list? ie. I want to know if "John Smith" is in Employees. I see there is a .Contains method but I can't figure out how to use it on a ListIf Employees.Contains(???) Then (need to check for "John Smith" here)
View 21 RepliesError:'Feedback' Must Implement 'Function GetRuleViolations() As System.Collections.Generic.List
Mar 20, 2009I need another (dozen) pair of eyes on this. The following code:
Interface iRuleEntity
Function GetRuleViolations() As List(Of RuleViolation)
End Interface
Partial Public Class Feedback
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is giving me this error:'Feedback' must implement 'Function GetRuleViolations() As System.Collections.Generic.List(Of RuleViolation)' for interface 'iRuleEntity'.
.net - Overrides A "list Of Base Class" Property And Returning A "list Of Child Class"
Oct 19, 2010I have a base class (ex: Class1) containing a list of another base class (ex: ClassA). Each child class of first base class (ex: Class1AA, Class1AB,..) containing a list of child class of second base class (ex: ClassAA, ClassAB,...)The client must never know which child class is using, then i don't think i can use generic for my bases classes.I try something like this and many more, but i always received errors..Imports System.Collections.Generic
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Windows Forms App: System.NullReferenceException Error
May 22, 2012I have been trying to figure out the source of error in my application. What this function (GetConcentrations()) is to display data from my database onto a DataGridView. The function is called in the PageLoad but works fine but when I call it in another Sub, I get this error.
Here is the code:
Private Sub GetConcentrations()
Dim conString As String = ConfigurationManager.ConnectionStrings("dbAsthmaConnectionString").ConnectionString
Me.dataAdapter = New SqlDataAdapter("Select * from tblConcentrations", conString)
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VS 02/03 Simple Database Program - System.NullReferenceException Error
Aug 14, 2009I'm trying to run a simple database and im getting a "System.NullReferenceException" error ) & "Additional Information:Object reference not set to an instance of a object" .
txtItemName.Text = rowCurrent.Item("ItemName") <-- highlighted in yellow
Code is as follows:
vb.net
Imports System.Data.OleDB
----------------------------------------------------
Public Class Form1
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Populate A List(Of Object) In A Class Method, Where The List Was Passed To The Method As A Parameter
Aug 13, 2011I'm trying to code a class of RandomNumber. One of the class methods needs to populate a "List (Of RandomNumber)" ... which was passed as a parameter to the method ... with 10 random numbers between 1 and 50. DEAD SIMPLE :)
View 6 RepliesVS 2010 Return Items In A List Before Returning The List?
May 23, 2012That was probably bad title, but I'll illustrate what I'm trying to do. I have a method in a class that I need to call several times. The method returns a List(Of String). I'm just grabbing some information from a database.
VB.NET
Public Function GetTestList() As List(Of String)
Dim int As Integer = 0
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VS 2010 Error Checking With List Box?
Jan 24, 2012I am working on a program that gathers test scores from the user in the form of a list box (array preferably). I need to be able to check the user's entries to validate they are between 0-100. I have tried using If statements with a messagebox.show() error message.When the user enters an invalid entry the error messagebox pops up but after selecting ok the program moves on to the next test score.
The GetTestScores procedure gathers the students test scores from the user
Sub GetTestScores(ByRef intTestScores() As Integer)
Dim intCounter As Integer = 0
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VS 2010 Sorting A Listbox (after Trying To Copy Class Instances Properties To A Temp List)
Jan 25, 2012I'm trying to figure out a way to sort the entries of a listbox... but in a different way instead of the obvious one (sorted property). First of all, I need to explain how the items are populated at first:
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Error : An Exception Of Type 'System.NullReferenceException' Occurred In EZEE Restaurant.exe
Jan 18, 2010For i = 1 To 60
Me.Controls("picturebox" & i).BackColor = Color.White
Next
i want to change backcolor of picturebox but when i run program,i get this error :
An exception of type 'System.NullReferenceException' occurred in EZEE Restaurant.exe but was not handled in user code
Additional information: Object reference not set to an instance of an object.i go to Project->Add reference and then look for "System.NullReferenceException" but i don't find it.
VS 2010 Error When Removing From List(Of String)
May 8, 2010For Each s As String In list
If s.Contains("Hello") Then
list.Remove(s) 'ERROR Collection was modified; enumeration operation may not execute.
End If
Next
Why do i get that error?
VB 2010 Express Compiler Error "Class 'CLSID_CorSymWriter' Could Not Be Created: System Error &H80040154&"
Jun 12, 2010I get the following error when trying to compile the simplest prpgram. Error 1 Class 'CLSID_CorSymWriter' could not be created: System Error &H80040154& After looking at other stuff on the net I removed VB 2010, VB 2008, any C or C++ runtimes and any .NET Framework programs I could find, and then re-installed VB 2010, but the problem still persists.
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Generic TypeOf Operator - See If List Is A List(Of T) Variable - Error: "Type Expected"?
Jan 5, 2011Dim x = GetType(List(Of )) 'valid statement
Dim list As New List(Of String)
Now I want to see if list is a List(Of T) variable: Dim isList = TypeOf list Is List(Of ) On the last line I get a compile error: "Type Expected". Is there any cheap-performance TypeOf operator alternative for generics?
CRM 2011 Sdk - Get Contact Info + Associated List IDs?
Jun 25, 2012Our CRM 2011 database contains approx. 20000 contacts, and I need to loop through all of them using the SDK. Currently I'm finding the following linq query takes a very long time to execute:
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Get Date Picker Info Into A List?
Apr 25, 2012when I try to use the code
Sub getReadings()
Dim intRead As Integer
Dim dateRead As Date
intRead = CInt(txtReading.Text)
dateRead = txtDateTime.Value comes from a date/time picker
txtTest.Text = dateRead
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lstListView is just a standard lstbox. Have no idea why this is happening or how to fix it. I can post the rest of the code if needed.