Dim myObject As Something There I defined my variable myObject of type Something. But, as you can see, I am giving it no value yet. Sometime on runtime I want to check if myObject is holding a value or not. I tried this: If myObject <> Nothing Then But apparently I can't do such comparison.
View 3 RepliesI want to created a nested class that can only be visible to and instantiated from the parent class.But I also want to be able to use an instance of the nested class through a public variable of the parent class.I tried making the nested class private, or making the nested class' constructor private, but it won't compile.Is it possible to do this in .NET?
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i have
VariableA as Class1
Variable1 as string
Variable1 = "VariableA"
I want to be able to use Variable1 to get access to VariableA(?).
So i want to able to do something like
VariableA.Property1 = "test"
But like this:
Variable1.Property1 = "test"
I need a static variable to get a ListItemCollection from a List control (I can do this, but if I don't set it as Shared It's not preserving the values as it should). The thing is that this class is a SharePoint webpart, so I most probably will be using the webpart more than once, and I need this variable to be unique to each webpart, which shared doesn't accomplish.I tried everything you can imagine. I placed a Static variable within a Sub (shared and not shared), I tried it with Properties (also Shared and not shared)...
View 3 RepliesI am trying to create new variables inside a class after creating its object at runtime. The problem is that I don't know the variable names or the value beforehand so I have to create the new variables at runtime.
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This is a more elaborate explanation of my code. If you observe that in the Eval function I have tried to evaluate Fval(abc). Now the object array abc is not declared in the Test class because it existence is not known beforehand. What I want to do is create an object array abc of length 2 and populate it with some values and when Fval(abc) is called then then the value of index 1 should be the return value of Eval fucntion.
I've got some code that looks like this:
If ediFileGroupAbbr = "NIPDSINV" OrElse ediFileGroupAbbr = "WWPDSINV" Then
Dim p As New PrivateBillingAdapter_ForN(ediFileGroupAbbr, businessLocationID, mode, EDIJobItemLogID, BusinessUnitID)
Return p.ProcessEDI(True, False)
ElseIf ediFileGroupAbbr = "FOPDSINV" Then
[code]...
to which I'm passing in a value of ediFileGroupAbbr = "FOPDSINV". But the code is executing as if it's dropping into the third condition (p is a PrivateBillingAdapter). So I've stepped into the code and, sure enough, it drops into the second condition. BUT, if I step into the execution of the constructor, the debugger jumps to an odd place in the code - sort of the middle of a method and not on any actual line of code.A couple clicks and it hops back out of the constructor, still in the second block of code. But if I mouse over the variable p to see it's type, boom, its a PrivateBillingAdapter (from the third block).Like I said, something is clearly wrong but I don't know what. I've tried rebuilding several times but with no new results.This is VS2003, framework 1.1 with VB.NET.
I'm tyring to pass a variable data type to a template class. Something like this:
frmExample = New LookupForm(Of Models.MyClass) 'Works fine
Dim SelectedType As Type = InstanceOfMyClass.GetType() 'Works fine
frmExample = New LookupForm(Of SelectedType) 'Ba-bow!
frmExample = New LookupForm(Of InstanceOfMyClass.GetType()) 'Ba-bow!
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I'm assuming it's something to do with the template being processed at compile time but even if I'm off the mark there, it wouldn't solve my problem anyway. I can't find any relevant information on using Reflection to instance template classes either.
(How) can I create an instance of a dynamically typed repository at runtime?
I thought this would be an easy one but I can't think of a good way to do it.User submits a webform. Based on submitted information I build three classes and assign their properties from received data:
UserInfo userInfo = new UserInfo();
UserAddress userAddress = new UserAddress();
UserEmployer userEmployer = new UserEmployer();
Based on submitted information some classes end up being populated with properties and some do not.
What's the best way to check whether userInfo class, for example, ended up with properties assigned ? I don't want to save a particular object to the database if it doesn't have any real properties assigned and all of them are set to either null or "".
I only want to save the objects that ended up with at least one real property assigned.ps. using NHibernate to save data to db
How do I define a variable which holds double quotes. when I try to define the variable like this [code]...
View 2 RepliesI've been trying to add a database to my interface, and i can't seem to filter the data, i want to search based on last name and only display people with the that last name (the last name will be entered in a search form).I've tried writing SQL Queries but I can't seem to pass the variable that that holds the last name into the SQL Query, to filter the data.
View 3 RepliesHow would I be able to make a variable that holds the value of the directories that exist in the C:?
View 2 RepliesOk, I want to create a class that will handle a special rectangle graphic.In my form, I want to have two of these special rectangles.So, basically, I need two instances of that class in my form, right?I manage to initialize two, alright. But, how exactly am I supposed to manage drawing/graphics etc in a class, and the results to be displayed in my form?
View 2 RepliesLet's say I have a custom class called CustomItem that holds the Name and 'SomeProperty' properties:[code]Now, on the click of a Button, I want to select the CustomItem whose SomeProperty is equal to "Property 4". Of course, this is just "Item 4", but the names and properties are not that correlated in the real application than they are in this example.I have spent ages a long time ago figuring out how to do this. I could not directly set the SelectedItem, because I first need to get the CustomItem that actually matches my condition (SomeProperty = "Property 4"). My solution was to use a loop, looping through each item in the ListBox, and setting the SelectedItem when the right property has been found.[code]Now, is this the correct way to approach this problem? Is the LINQ query correct, or can it be done easier, without the casting? Also, is the LINQ query faster than the For loop, especially for a large amount of items? I expect it to be, but I don't know how to test this.
View 4 Replieshere I am again I have written a small class called 'Messages' that holds the user messages.The case is that I am not being able to import it. Here it is:
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why don't we declare a variable for instance variable with dim not private?
View 3 Repliescreating single instance form in MDI Application. How to check whether form's instance created or not?
View 6 Repliesmy proble is the following: I have a class MyClass and another class Modifier, which has a method ModifyMyClass(ByRef mc as MyClass) that receives a MyClass instance as ByRef parameter to modify it. A smell of the code is:
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I have a class in which some of the fields are also classes.I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition
dados_Defenicao.arCode = "123"
dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
How can i fix this ?
I have a class in which some of the fields are also classes.
I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"
But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition
dados_Defenicao.arCode = "123"
dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
If you run this code you will see that the 500 PictureBoxes that are added ( this is easier to show than adding pixels as a pixel is only a single point ) fall mainly on the diagonal.With regard the RANDOM class, why should this be like this when the bounds of the instances are? >>
p.Location = New Point(x.Next(0, Me.Width + 1
), y.Next(0, Me.Height + 1 ))
as in this code.>>
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I've createda vb.net class library where I've defined a number of small classes... nothing complicated, just working with strings, sending emails, etc.In another project, I reference the class library and I'm seemingly able to create an instance ofone of tclasses - intellisense shows me all of the plic properties, methods, etc... all looks perfect. No compile errors at all, nothing b gumdropsand lollipops.When I run the app I'm working on that references the class library, it fails at the point where I'm creating an instance of the class and gives me a vague exception, "System.TypeLoadException".
View 2 RepliesIs there a way to define a class such that there can be only a single instance of that class?
View 5 RepliesI need to create a new instance of a class that needs a member of the calling class. But i can't pass a reference to the calling class through the constructor.The solution i am looking for is something like this:
Public Class ChildClass
Public Sub New(args)
_MyMember = GetMemberFromCallingClass()
[code]....
I want this to work without having to manually pass any references or variables from the calling class to the new instance of ChildClass.
I want to create a class that will "search" for something. Basically I load up the "search item" when the class is created and inside the class is logic to do the "search". The result of this logic will be more "searches" that I want to start. How can I have the logic in the class create another instance of the class itself?
View 3 Repliesi had a class called Tag with a structure like:
public class Tag
private _members
public properties
public shared database_methods
end class
this class was tailored for mysql database. i'm currently adding access 2007 support so i split tag into tag and tagdata with structures like:
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I have a for next loop looping through a dataset.I want to create an instantce of a class for each row.How can I create another instance/variable for each row?
View 5 RepliesCreate a class named Service. Inside the Service class, declare a class variable named Started. The datatype of this variable is Boolean.Public Class Service Dim started as Boolean End Class Create a class named Server. Inside the Server class, declare a dynamic array that can contain elements of the type Service.(Note: For convenience, both the array and the variable Started can be accessible from a client program that creates an instance of Server and Service respectively)
Create a constructor for the Service class. When the constructor is executed, it will set the value of the class variable Started to True. Create two new classes: WebServer and DatabaseEngine. Both of these classes inherit from the class Service. Inside the Service class, declare a Sub procedure (method) named Terminate. This method should display the following text Service stopping in a message box when executed.This method can be overridden in classes that inherit from Service class.
Inside both the WebServer and DatabaseEngine class, override the method Terminate inherited from their base class Service. Both methods should first call the base class Terminate method. The messages Web server stopping and Database engine stopping should also be displayed in a message box when the Terminate method for the WebServer and DatabaseEngine are called respectively. These messages should only be displayed if the Started variable inherited from their base class is not equal to False.
Inside the Server class, declare a method named Shutdown. This method does not return any value. When executed, it will call the Terminate method for each of the Service instances (if any) in the arrServices
array. You should call the Terminate method within a For Each loop that loops through the elements of the arrServices array.
In the Sub Main method, create an instance of the class Server. Set the size of the arrServices array in
your Server instance to contain 2 elements. Create first a WebServer instance and then a DatabaseEngine
instance into this array. Call the Shutdown method from your Server instance.
I have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch)
Try
Me.cv_clsB = clsB
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I have three class files, accounts.vb and transactions.vb in addition to my form.vb. I am unable to retrieve a member variable from on class from inside the other. When the combobox index changes, the program loads the correct account (checking or saving) from two different sequential files. I don't think I have the calcBalance procedure in the correct class file. And that is what I am having trouble with. Accessing it to display it. [Code]
View 1 RepliesHow many instances of a shared variable will be created in a class? just one? correct
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So, in other words, the DocumentDelivery class will only have one instance of RenderList, correct? can somebody confirm?