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 RepliesI 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 RepliesI'm trying to get the ATM Class to Instantiate on the Form class.
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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?
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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 Repliesthis 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?
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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 Repliesi'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])
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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()
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
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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?
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
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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 RepliesI have an ASP.NET web site project where I am using both VB.Net and C# class files. I have included separate sub folders in the App_Code directory for classes of each language.However, while I can successfully make use of a C# class in a VB class, I cannot do the opposite: use a a VB class in a C# class.
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I get an error that "the type or namespace "VBTestClass" could not be found". What am I missing here?
dim myCollection as new Specialized.StringCollection
dim myFoundThings as new ArrayList
dim index as Integer
dim newResultMemberName as String
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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.
I am not sure if this is possiable but I am looking to build an application that will login to a web site, navigate the site and download files. I would like to do this all in code and able to run multiple instances of the program to get information from many different web sites. Is something like this possiable in VB.net?
View 3 RepliesIve got an app that holds a list of site we have, At each site there are a few devices. The idea is when they click on a site all the details for the site are loaded and then a second thread sits and pings each device to see if its live. Im trying to do this in a seperate thread so if they click another site while its still pinging them it doesn't wait before it switches site. This all seems to be workling fine except if you click through the sites quickly, when you do that it will eventually come up with
Quote:
{"Collection was modified; enumeration operation might not execute."}
The error flags up on the "Next" line in "ThreadedPing"
Thread stuff
Public Sub ThreadedPing(ByVal dt As DataTable)
Try
Dim dr As DataRow
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When i publish my program i choose to let the application check for updates via a website and if their is one update automatically when the program starts. Is their a way were on the main user form i can make it so that the user can change the update site with out me building the program again with the new site. I want to do this becuase the site i use goes down alot so when i changed the update url no one was able to download the update for the new update server.
View 16 RepliesI'm deploying a VB.Net app (VS 2010 Pro) that requiers the user click a command button to open IE to a financial WEB site and download informaion from the site. The app works fine in every detail when installed on the development computer. But, on the target computer when the command button is clicked an unhandled exception occurs which says: System.IO. FileNotFoundException:File Not found.My code behind the button is Shell("C:Program Files (x86)Internet Exploreriexplore.exe www,fidelity.com",AppWinStyle.NormalFocus)
This works fine on the development computer. Do I need a way to code this as a relative path? If so,can you tell me how this is done?Throughout the app I have written relative paths to needed files using paths like (Open(Environment. GEtFolderPath (Environment. SpecialFoldder.Desktop) + "File Name). They all work fine when deployed.
I'm being asked to maintain several internal-only web apps for my company. For testing, after making my changes, I've created some staging sites which make use of separate databases. As such, if my users were to mistakenly use this site as if it were the production site, they may enter important data and wonder where it "disappeared" to thinking it was the production server.
I'd like to create a big banner of some sort across the top of the staging site (which ONLY appears on the staging site) to remind my users that they are on the test site. I'd like recommendations on the best way to do this, with the following considerations:
IDE: Visual Studio 2008
Server: Windows 2003 with IIS 6
Language: VB.NET 2.0
i want to know how can i code my button when i click it will open my site ... i Think i was clear.
View 1 Replieswhen i am surfing in one site,i want to see the another URL...without going URL directly access the login......for example this is the login page url i want know automatic login to this page [URL]
View 1 RepliesIf I have a console application containing the class
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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?
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 RepliesI 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?
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
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.
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()
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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.
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.
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?
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