I keep Getting a NullReferenceException Error but I have declared a NEW structure. See below:
Structure ISACReply
Public RTD As ArrayList
Public SAC As ArrayList
Public DRT As ArrayList
[code]....
When I try to execute the subroutine "calltest" I get a NullReferenceException in the line that says " rv.DRT.Add("HELLO") " even though I have set rv to an instance of ISACReply using NEW.
I have two structures Public Structure myResearchData
Public batchName As String
Public arraylistRData As ArrayList
End Structure
Public Structure myResearchSubData
Public researchDescription As String
[Code]...
Cleared MyResearchData.arraylistRData for new data to be put in but it also clears the arraylist inside MyResearchDataAList and didn't old the contents of the arraylist
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I m getting an error NullReference Exception was handled at this line of code
Dim snmp As New SimpleSnmp
snmp = New SimpleSnmp(host, community)
coming from this question i was wondering why:
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'this throws an "Object reference not set to an instance of an object"-Exception'
[Code]....
A CType(obj, Boolean) would evaluate to False(just as CBool(obj)), i think because the compiler uses a helper function, but that is not my theme. Why does casting Nothing to Boolean evaluates to False, whereas casting an object that is Nothing to Boolean throws an Nullreference-Exception? Does that make sense?
I am developing a windows application in vb.net and getting an error of system.nullreference exception.I am trying to insert data in the database, insertion occurs in the first go. But, when i stop the porgram and re-run, i get the exception.
Imports System.Data
Imports System.Data.OleDb
Imports System.EventArgs
[code]....
I'm getting a design time NullReferenceException on Dim db As Database = DatabaseFactory.CreateDatabase()and I can't figure out what to do about it. Has anyone experienced this problem or know the solution?
View 6 RepliesI have a TreeView with a parent node and two children node. Each of the nodes contain a checkbox stored in a TreeViewItem. I want the two children node checkboxes to be set to IsChecked=true when the user checks the parent node and I want the two children node checkboxes to be IsChecked=false when the user unchecks the parent node.
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I want to make a structure within a structure. Basically it will appear like this:
Structure ID
dim CardType as string
im CardCode as string
[code]......
I have created a Class Library (dll) with a module and a class in it.The module declares a structure, and an instance of this structure.In the class, there is an arraylist declared.My main program calls a function in the class library class. The class calculates data, stores it in the instanceof structure. Then adds it to the arraylist.When i want to use this data in my main program, i get a Cast void error. Its because The structure of the data in the array if of the structure in Class Library module. Is there a way to change the structure of this array to an identicle structure in the main programs Module. When the function returns the arraylist I have tried storing it in a tmp arraylist and copying, cloning etc the data into another arraylist in my main program. still not working. Do i have to loop through all the data and copy each value to a new instanceofstructure, and store this in the new arraylist?
View 3 Repliesa simple question:I have this structure:
View 8 RepliesI was wondering if I can use an ArrayList inside a structure as one of the structure's properties.Or it may be better to replace the structure with a class. If so, can I use an ArrayList as a property of the class.So what I want to do is have the ArrayList as the property of the structure and be able to add items to the ArrayList and clear the ArrayList from a clear method of the structure.
i.e.,
structure.ArrayList.Add (item)
structure.Clear
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I'm trying to use my own structure as a dynamic array (ArrayList?) but can't find the right syntax.
Public Structure BLsCompsRootDir
Public BL As String
Public Component As String
[code].....
i got this code from the net , but i can't make this code work on the system i am programming so, i used the same codes to another system and it worked, when i tried using it to my system, it failed, so i started a new program and it still fails... what is wrong with my program? here is a sample of the code:
[code]...
whenever i run the program, it compiles, but when i click the commit button, this message appears "NullReference Exception was unhandled Object reference not set to an instance of an objects" and it points to .NewRow
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.
When the following executes, I get the error 'NullReference Exception' - Object reference not set to an instance of an object. TestClass has Get and Set methods for the integer property TestWord.How should the following be changed to let me set TestWord in six elements of TArr?
Dim TArr(5) As TestClass
For i As Integer = 0 To 5
TArr(i).TestWord = i * 10
Next
I have a function which iterates through the TextBoxes in my form (and its child controls) and adds each TextBox's name and text to an ArrayList using a structure I called valTxtBox.
Here's a snippet of the
VB.NET
Public Structure valTxtBox
Public nome As String
Public texto As String
End Structure
[Code] .....
Now, the problem is that if I call Clear() for valsTxtBox in the getctrls() function, not all the elements get added to the ArrayList. However, if I don't call Clear() it works just fine. BTW, I'm using VS2008 express which might be relevant.
I have a structure like this:
Code:
Public Structure Interval
Public temp As Double
[Code].....
'I want to be able to add to the array like an ArrayList though... 'after assigning values, like this:
interval(0).add
After gathering the Machine names on the (sealed) LAn i am then getting the ip addresses, MAc address and Macine User name of each machine on the LAn..These details will need to be accessed seperately for use in the security testing and i am unsure how best to store the active data (though eventually in a database) Am i best to create a Multidimensinal arrayList or array(bearing in mind that all the data is convereted to "String" (arrays can only store one data type??) The data found on the live network is allways changing making an array a difficult choice? I have read some tutorials mentioning making a structure with the data and storing this in an arraylist but i dont know whether this will make accessing the individual data items (ip,MAc,HostName etc) a difficult procedure?
View 1 RepliesWhat I am doing is iterating through all the groups that belong to the top group (Generic reports). Then I take advantage of the GroupPrincipal.GetMembers(True) which will recurse through a given group name. I test to see if the user exits under that group and if true I put the group name in an arraylist.
I use the for each principal in GroupPrincipal.GetMembers to loop through each returned user to see if they exist.
Is there a way to put all the returned users Principal.Name from a given group in GroupPrincipal.GetMembers into an ArrayList? This would allow me to to use Arraylist1.IndexOf to search for user. Which would be much faster then iterating through a returned list using the for each construct.
Sub RetAllMbrs(strUser As String)
Dim oPC As PrincipalContext = GetPrincipalContext() '<- this is function somewhere else in the code
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I have a problem in Treading.I have a code like this;[code].....
I want to change ListBox1 with ArrayList. But I couldn't find how to use adding a string to ArrayList in tread.
I have an arraylist (arrFirstArry) which I use to populate another arraylist (arrNoDuplicates) preventing any duplicates from being added. This works fine. What I would also like my code to do is prevent adding any partial values which may exist from being added. i.e. my array is like this
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What I need to do is read an ArrayList in My.Settings and add another ArrayList to it. The first think I'm trying to do is load My.Settings.Records into myArrayList. I'm not quite sure on the proper way to do this. I've tried things such as Dim myArrayList As ArrayList = My.Settings.Records, I'm not sure if I need New and I'm not sure if I need .Clone or .CopyTo.
Then I have another ArrayList myArrayList2. To get this into myArrayList I've done: [Code] Then to save it back to My.Settings I've done. My.Settings.Records = myArrayList. The problem is I keep on getting Object reference not set to an instance of an object error on the AddRange line. My.Settings.Records is definitely an ArrayList and it will sometimes = Nothing. The objects will only ever be strings.
I have a function that gets a string passed to it.When testing the function, I'm getting a null reference exception on the string parameter that gets passed to it, even though the string is not null, I don't understand why I'm getting this error.I used a dummy value to verify both the string parameter in the SelectSingleNode function and the newValue string parameter being passed to my function and they both contain values, so I don't understand why it's throwing a null reference exception. Just for clarity, the purpose of the function is to write values back to the nodes of an XML file.[code]
View 3 RepliesI have a function that gets a string passed to it. When testing the function, I'm getting a null reference exception on the string parameter that gets passed to it, even though the string is not null, I don't understand why I'm getting this error. I have a screen shot belowI used a dummy value to verify both the string parameter in the SelectSingleNode function and the newValue string parameter being passed to my function and they both contain values, so I don't understand why it's throwing a null reference exception. Just for clarity, the purpose of the function is to write values back to the nodes of an XML file.UPDATE
Private Sub setValue(ByVal nodeToMod As String, ByVal newValue As String)
''Test writing to xml config file
Dim dummy As String = "Config/" & nodeToMod
[code].....
The second Case in the first Sub is the one giving the error message.The second Sub is the part I (Removing the Label so that it can be recreated later) fix this code block? I do not know the correct way of removing or desposing a Label, as you can see the Label
Public Class Form1
'<<< Indecating if the app. is in Reading, Editingor AddingNew.>>>
Dim ModeIndecator As String = "Reading"
[code].....
I'm building a simple game in an ASP.NET/VB.NET web app. The game has a UI made up of several ImageButtons. The web page's code behind file holds an instance to the game object which will manage each turn taken by players. Everything worked when the Game object's methods were Shared. The problem occurred after refactoring to make the game object work as an instance instead of a shared class. Now, when the action returns to the code behind, the instance of the game object is nothing.
The code bits:
Public Class _Default
Inherits System.Web.UI.Page
Private _gamePanel As Panel
[code]....
It is possible to catch an exception and throw a new exception which wraps the first exception as an inner exception: [URL] Also, if I call a function and it throws a certain error, but I catch it, will the calling code's catch handler execute? If so, and it is of a higher exception type, is this not wrapping the exception? eg I can throw exception ex of type IndexOutOfRange, log it but rethrow, catch a higher up exception and do something, or I can throw a new exception and wrap an inner exception like:
View 1 RepliesModule Module1
Public Structure structure1
Public TRANS() As structure2
End Structure
Public Structure structure2
Public X() As Integer
End Structure
End Module
I'm new to VB 2008 after having spent a long time with VB6, so I apologize if this is a stupid question. But I'd really like to have this straightened out.
Let's say I have a pretty large structure that has lots of properties.
Code:
Now say that I want an internal database with about 10 instances of this structure total, describing, say, 10 different products that a store sells. When these values are loaded from a database, they remain totally static. (However, they can be different each time a program loads)
Now say that I have a class. Each instance of this class is a type of that BaseProduct structure. Meaning, each instance of the class pertains to one of the 10 types of products that the store sells. However, this class has additional properties that pertain specifically to each instance, which are not static.
Code:
Now, the problem here is... If I have 200 different transactions, each one contains an instance of BaseProduct. BaseProduct is HUGE, and is largely redundant (only 10 types possible), so I think it's a little silly to include a whole copy of it with EVERY transaction. However, the Transaction class really needs information regarding the base product it pertains to. Is there a way to, instead of declaring a New BaseProduct in the Transaction class, to simply make one of the properties of the Transaction class a pointer to a BaseProduct variable?
In VB6, I would accomplish this by making a BaseProduct(10) array, and then giving each Transaction an ID number referring to an entry in that array. But in VB 2008, using class structure, this is impossible. I can't define the BaseProduct(10) array outside of a class in a namespace, and if I define it in the actual application's form, then the class loses modularity since it relies on the application that's using it.
I am trying to communicate with an external device and i am trying to send a byte array to the external device via sockets but i am always getting a response the message size is too small so i am not sure what i have done wrong. Between the data type there should be no alignment present and all numbers are represented in little endian format. The char array is not null terminated as mentioned in the protocol specifications.
I have to send data based on a struct that embeds 2 other struct. So here's my vb.net code for the struct used to convert to byte array and the sending part.
Public Structure MESSAGETYPE_OIP_Login
Dim Header() As COMMANDHEADER
Dim UserName() As PSTRING
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