When we create an instance of a class we also provide its state so are these both same and if not same what's the difference? And also what's the difference when we use equals method for instance or for state?
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I 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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my 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 have a base class called PageBase and then a derived class TestPage that inherits from PageBase. In PageBase I have overridden the OnInit() and when it is called and I inspect the value of 'Me', it is of the type of the derived class and not the base class. My question is how does inheritance really work? For instance, when instantiating TestPage does an instance of PageBase get created too?
Here is my code;
Partial Public Class TestPage
Inherits PageBase
Public Sub New()
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if I put controls on form1 like button,textbox....etcwhy called this control fields not object in the class diagram ?
View 7 RepliesI'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()
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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 RepliesOkay so what im trying to do is make a simple particle system in VB (Yes i know this isnt a ideal setup). Im going to have particles dieing and spawning new ones tho, To do this i need to be able to pass a function to the particle when its created then call that function when it dies. Is there a way to do this by passing function pointers?
View 9 RepliesI am trying to use a DLL that has a public class called FileCleanUp..Inside this class is a procedure called ProcessFiles as shown [code] In VB.Net how do I access the ProcessFiles events so I can inform the user on progress etc from my VB.net application that calls this DLL.By using Reflector have found that the DLL uses the Background Worker if this is of help.
View 1 RepliesI have a Dynamic Data application to which I have added a class for extending EDM. Everything works great, but now I am trying to set an entity property value equal to a value in session state - and its not recognizing the Session command. I'm trying to do something like this:
audit.action_by = CStr(Session("person_name"))
I think this is because I do not have the class Inheriting Page, but if I do add Inherits Page it breaks other stuff. How can I have the class include the ability to utilize sessions directly without inheriting Page?
How should class member variables be used in combination with class methods?Let's say I have a class 'C' with a member variable 'someData'.I call C.getData(), which does not return a value but instead puts data in C.someData. The class that instantiated 'C' first calls C.getData and then uses the data by accessing the member variable C.someData.I call C.getData() in the class that instantiated 'C' which is a function that returns data.I myself prefer the second way. But it also depends on the situation and it's a small difference. Is it 'bad' to have class methods that depend on the classes internal state? What are the best conventions?
View 2 RepliesThis is code i have in a class called appmgr which runs at startup of app
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I have a class that has a destructor and a Dispose method (I also inherit IDisposable). Why is it that the only time my destructor gets called is when I call GC.Collect()?
View 2 RepliesHow do I force the Visual Studio compiler to generate an error when a required method is not being called in the constructor of a child class? Like when you edit the form designer code, the compiler complains when InitializeComponent()isn't the first call in the constructor of a form. Is this even possible in VB.NET?
View 2 RepliesI'm wondering if there's a way to programatically reference the class that called a method in another class. Let me give you an example:
Public Class OriginalClass
Private Sub Main()
Log.PgInit()
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I've an app that starts to work from a module wich should load a form an do other things with a class library who raise an event an the form shoud cath it.The problem is that applicarion.run(frmMain) displays the form in the same thread the the code stops work while the form is open. And I need that the app works in this way because the user need to send files to the app using args and this avoid that the app init another instance of it (in other code) and update the form with the info when the event is raised.[code]
View 9 RepliesI have created an application where from the starting class a modless dialog box is called. Once the dialog box is called then the program will close instead of waiting on the dialog box to call the appropriate functions.
A couple of notes: This was originally written in VB 2005, and I was successful by manipulating the automatically generated code for the starting and clean up for the class. I cannot find this section of code in my VB 2008 project.
I cannot start the program from inside the dialog box, since there are multiple dialog boxes and which one starts depends on what is currently running on the computer.
The program will run with a modal dialog box, but it does not function properly, so I must use modless.
Please help me to prevent the application from closing when it reaches the end of the code in the main subroutine. I want to have a function to explicitly close the application.
I am working with tasks, so I've got the following code to update a label on my form:
Private Delegate Sub UpdateLabelDelegate(ByVal s As String)
Public Sub UpdateLabel(ByVal s As String)
If Me.InvokeRequired Then
Me.BeginInvoke(New UpdateLabelDelegate(AddressOf UpdateLabel), New Object() {s})
Return
I've an app that starts to work from a module wich should load a form an do other things with a class library who raise an event an the form shoud cath it. The problem is that applicarion.run(frmMain) displays the form in the same thread the the code stops work while the form is open. And I need that the app works in this way because the user need to send files to the app using args and this avoid that the app init another instance of it (in other code) and update the form with the info when the event is raised.
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I created an interface - TermsService.vb and defined the following method : Function GetTermsList() As List (Of Terms)
how do I modify my TermsDB class to implement the TermsService interface I've just created? Here is my code: Have I implemented it correctly?
Imports System.Data.SqlClient
Friend Class TermsDB
Implements TermsService
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Let'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 RepliesIs there a way to get the instance's class name with VB.NET?
View 2 RepliesI have been asked by a code snippet to add the instance of class that contains data i want to add to an XML file, the only trouble is i am not sure what an instance of class is. Is it something that looks like this: [Code]
View 2 RepliesI am working on an ASP.Net 3.5 solution that I did not originally build. I added a class file named Incident.vb to the App_Code folder like I always do.But in my code behind of a web page, I usually create an instance of a class like:
Dim oIncident as New Incident
But after I type "New", normally I would see my class file he intellisense but I do not. So it does not seem to be able to find Incident.vb. I have not seen this behavior before. Trust me, my class is correct. I have created many class files like this.[code]...
I think I just need a push in the right direction. I cannot seem to get my sub from an instance of my class, once instantiated, to run when I click on the button. My Code in the class is
When I click this:Private Sub btnBark_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBark.Click
mydawg.bark()
End Sub
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