Programmatically Choose Class To Be Instantiate
Jul 7, 2010
I am currently playing around with VB.Net using Visual Studio 2010 (.Net 4.0) and I need your help to create a collection class (let's call it 'cl_MyCollection') with a constructor that accepts two arguments:An SqlDataReader object Some means of pointing to a custom class I have created.I have five database tables in SQL 2000 and five VB.Net custom classes.Each custom class contains a variable for each field of the table the class represents.For example:"tbl_User" has 2 fields "User_ID" and "User_Name" and tbl_Family" has 3 fields "Family_ID", "Family_Name" and "Family_ Location". [code] Fixed typo, the select case now points to the second argument ('selectedClass') as originally intended.
View 2 Replies
ADVERTISEMENT
Jul 22, 2010
I have an Account Class that is able to create notes(Class), however i am able to create the note object by itself which is not the desired outcome, i want only the account class to be able to create the note object. Another Example would be, an order item should not be created without an order class. But how do you enforce this in vb.net.
View 8 Replies
Nov 22, 2011
I'm trying to get the ATM Class to Instantiate on the Form class.
[code]...
ISSUE = " 'ThisATM' is used before it has been assigned a value. A Null reference exception could result at runtime"
The Other problem i am having is with a class in the program called CardReader. What am i supposed to type to let the code below be able to "read" the read function on the Form1?
[code]...
View 7 Replies
Sep 28, 2009
I have created a WebSite with a folder called Classes. In the folder, there is a class with a Public Shared Function. How do I go about instantiating that class so I can use that function on a web form?
View 5 Replies
Jun 11, 2009
I'm trying to decide whether to get a value, call it X, in my class through a read only property or through a function. Normally I'd code it as a property except in this case the GET involves doing a lookup to a sql table. So there's way more overhead than a simple RETURN X. So my question is, when I instantiate a new object from my class, are all the properties calculated at that point, so that the sql lookup will occur too? Or is the property only evaluated when I actually reference it in the calling code.
View 3 Replies
Oct 13, 2011
this is what i want to do. I have a class library project into my solution. Into it i have a class. I want that class to be instantiated as soon as the solution starts. So it can be accesible from the other projects in the solution like this: Namespace.InstanceOfTheForm.Property Is there any way to do that? or something close to that?
[Code]...
View 2 Replies
Mar 16, 2012
I am developing a program to manage inventory and accounts. different clients need different databases like oracle/sqlserver/mysql etc. i want to make my solution work with all these database servers by only changing one string value . i want to declare like :
[Code]...
View 2 Replies
Sep 27, 2011
i've got a generic class for xml serialization and deserialization.
Public Class clsXMLHandler(Of T)
Public Sub serializeFromObject(ByVal filePath As String, ByVal [object] As T)
Dim creater As New FileStream(filePath, FileMode.Create)
Dim xml As New XmlSerializer([object].GetType)
xml.Serialize(creater, [object])
[Code]...
View 1 Replies
Jul 7, 2011
I'm sure I've seen this done in 4.0 but can't remember how it is done.
Basically I want to instantiate a class and call a method of that class on the same line of code.
So something like this
Dim s as String = new myClass().getTestString()
View 2 Replies
Jun 22, 2010
I see a sample code that an object is instantiated within the class definition block. But when I test the folllowing, I got error "Process is terminated due to
[Code]...
View 3 Replies
Sep 3, 2011
System.String is a class type, but why we can use it without instantiate it with New keyword?
For example:
Dim CommandLineParameters As String = Microsoft.VisualBasic.Interaction.Command
No new keyword being used at all?
View 4 Replies
Apr 13, 2011
I am trying to run a backgroundworker to load data from my DAL (which is available in another class). I want to keep the UI available and not have the "locked up" feel while the object is loading.When I create a simple backgroundworker and Sleep the UI stays responsive and my controls can be updated after the sleep. As soon as I replace the sleep with a call to instantiate the object from my DAL, the UI locks up. Is there someway I can instantiate this object using the background worked and keep the UI responsive?
When the situation object is instantiated it could take several seconds for it to load completely, during this time is when the UI is locked up... It does eventually load just fine.
Private WithEvents backWork As New BackgroundWorker()
Dim sit As Situation
Private Sub btnLoad_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnLoad.Click
[code]....
View 1 Replies
Aug 23, 2007
I am creating user accounts in Active Directory via vb.net.Once the account is created I need to assign permissions to the "homedirectory" that I have assigned in Active Directory.I have access to the Active Directory name attributes but I need to convert these to a NT account format ( DOMAINAccountName ) to add security via the DirectorySecurity AddAccessRule method.Is there a way to instantiate the NTAccount class from an Active Directory Entry? I'm not sure if this is necessary I just found that class and it looked like a good fit; a simple routine to create the DOMAINAccountName from the Directory Entry attributes like cn might also suffice.
View 6 Replies
Nov 4, 2010
I want to set a variable in a class. But I want to dynamically choose which variable to set.
[Code]...
View 1 Replies
Feb 24, 2010
-edit- nevermind i was lucky and didnt need to change much and have this test working.I am doing a quick test and i need to choose the full path to a function.in C# i can write namespace ABC { class DEF { static string Test() { return "A test"; } } } and can access it with ABC.DEF.Test() i tried
Namespace ABC
Partial Public Class DEF
Public Function Test(ByVal v As String) As String
[code]....
and i got VBTest.ABC.DEF.Test(). How do i get rid of VBTest which is the name of my project?
View 1 Replies
Aug 11, 2009
dim myCollection as new Specialized.StringCollection
dim myFoundThings as new ArrayList
dim index as Integer
dim newResultMemberName as String
[code]....
This is part of some code that will run without user interaction once it's spinning away, and I need to create a unique object from some items found in a StringCollection, naming the objects using information found in the strings stored in that StringCollection.
View 2 Replies
May 10, 2009
Is it possible to create a class programmatically?
View 2 Replies
Jan 15, 2011
Am a geriatric coming back to programming after a decade's rest. Keeping it very simple. An empty form. As the form loads, create a Black button (OK) and also create a class which itself creates a single Cyan button. Am using VB 2010 Express. When I run, it creates the Black Button but not the Cyan (i.e. the one that is generated by the class).
[Code]....
View 11 Replies
May 7, 2012
I am looking for a way to add an interface implementation to a class at runtime.
Here is a sample code, which I will discuss below.
Public Interface IAction
Sub DoThis(a As Integer)
End Interface
[Code]....
This is related to WCF, where one needs to provide to CreateHost a single class, which implements all interfaces required for the end points. In this scenario, ActionDispatcher is such a class, and IAction is one of the many interfaces to be implemented.
My vision is to avoid implementing IAction in ActionDispatcher manually, but have some sort of registration mechanism, where I can say, that ActionDispatcher must implement interfaces IAction, IDoing, INoAction, etc - and have the dispatching methods generated for me.
MSDN says, that any class is compatible with any interface, so I don't need to declare "Implements" in the ActionDispatcher. But I still need to implement the interface and connect the implementing method to the interface definition, so WCF can find it when needed.
The closest thing I found is probably the Automatic Interface Implementer, but it (1) creates a new type, (2) adds dummy methods.
I has also tried to understand CodeCompileUnit class, but so far couldn't see the relation to what I need.
View 4 Replies
Sep 11, 2010
I have code like this...
Public Class nomatch2
Inherits System.Web.UI.Page
Private Sub nomatch2_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If IsPostBack Then Return
log.PgInit("nomatch2.aspx")
'Do other stuff here
End Sub
End Class
View 2 Replies
Dec 20, 2011
I am currently working on a family project which is based on "Who Wants To Be A Millionaire?" show. There is a huge diffrence between the show and my project. My project is a christmas edition and the goal is not to get money or something, since I will not add it... Erhmm... Let me get to the point. I have already designed a layout and scripted some things. I have about thirty questions but I do not want them to always spawn in the same array, if you know what I mean. I want the program to randomly choose one of those thirty questions and NEVER choose the same question in the same program run. By the way, there are four options on my project: A, B, C and D. I have got everything, I just need a code.
View 3 Replies
Dec 13, 2011
If I have a console application containing the class
[Code]...
I'm not a VB.NET guy. Am I correct in assuming I need to instantiate my object first? Why does the VB.NET example differ?
View 1 Replies
Jun 5, 2009
I want to instantiate and name a listbox based on the value of a textbox. If the listbox already exists by this name (textbox value) I want to add items to the list.
View 14 Replies
Jan 7, 2010
I sort of understand why this is happening, but not entirely. I have a base class with a Shared (Static) variable, declared like so:
Public Shared myVar As New MyObject(arg1, arg2)
In a method of a derived class, I set a local variable like so:
Dim myLocalVar As MyObject = myVar
Now when I do something like myLocalVar.Property1 += value, the value in Property1 persists to the next call of that method! I suppose I get why it would be happening; myVar is being set by reference instead of by value, but I've never encountered anything like this before. Is there any way (other than my workaround which is to just create a new object using the property values of myVar) to create myLocalVar by value?
View 2 Replies
Oct 31, 2009
i wanted to do something simple that sort of replicate an object:
public function clone(byval realcopy as object) as object return new Control ' something like this works, however i want to return the type of realcopy, which may not be a control end function so i tried this:
public function clone(byval realcopy as object) as object
return new gettype(realcopy.gettype)
end function
View 3 Replies
Jan 24, 2011
Just a bit of an issue that we're trying to resolve here. Assuming We're implementing a business model as one dll and a data access layer as another dll. We want them to be de-coupled so we implement an interface for the data-access layer. Great, we could now swap out the data access layer and, as long as the new data access layer fulfils the interface we're good to go, right?
Except we're not. In the business model we need to insanciate the data access layer and, because you can't instanciate an interface, you have to instanciate the actual class. We need to know the name space and the class name.We're going to end up with a line of code somewhere in our business model that looks something like this:-
Dim test as iDataLayer
test = new namespace.DataLayer
Basically, we can declare test as an iDataLayer (the interface) but to instanciate it we need to refer to the actual class (DataLayer). So we haven't really removed the coupling. If we want to swap out the data layer for a different implementation with a possibly different class name or namespace then we need to ammend the code in the business model. We're trying to avoid that.
So far the best we can come up with is to use the activate instance method instead of the New keyword (Late Binding). Because that takes a string we could hold the namespace and classname in a config file or similar, so swapping out one component wouldn't invalidate the others, you'd just need to update the config. That's just our home-spun solution though and I can't help feeling there are betters ways out there.
View 9 Replies
Mar 5, 2009
I'm trying to figure out if it is possible to instantiate and invoke a delegate by name, rather than explicitly. I think the code below explains it fairly well. I want to accept a function name and then instantiate the delegate based on that. In the example I use a select case, but I want to eliminate that and just use the methodName argument itself.
Private Delegate Sub myDelegate()
Private Sub myDelegate_Implementation1()
'Some code
End Sub
Private Sub myDelegate_Implementation2()
[Code] .....
View 4 Replies
Jun 5, 2009
I have defined an interface named IEmployee (ID, FirstName and Surname properties) but I have not yet implemented that interface in any class. What I want to do is something like:
Dim User as New IEmployee
User.ID = 1
User.FirstName = ""
User.Surname = ""
Call SomeFunction (User)
The VB.NET complier does not seem to like this.
View 6 Replies
Aug 25, 2011
what actually goes on inside the pc when I reference an object vs when I instantiate it.
Like this
Guys joe; (reference)
Joe = new Guys; (instantiate).So what goes on inside the computer for each line above.
View 15 Replies
May 5, 2010
I used different backgroundworkers to instantiate some 'heavy' forms thinking that it will reduce the time to instantiate them if I did them at once but it looks like I am wrong since it is still taking about 43 seconds to load all of them. Am I missing something or do you have a tip on how I can speed up their instantiation?
View 15 Replies
