VS 2008 When To Create A New Class Instance
Jun 22, 2010
I understand if i was to create my own class i would need to declare a variable with the new keyword to create an object to access the encapsulated methods properties etc, unless they were declared shared.
dim myVar as myClass = new myClass
But in this next example is where i have become confused. i have added the mschart control to the form and used the hittest function with the following code.
Dim myVar as hittestresult
myvar = me.chart1.hittest(e.x,e.y)
Why wasn't it necessary to create a new instance of the class 1st. Does the hittest function return an object or a reference pointer to the object. To clarify what's the protocol for when & when not to create a new instance of the class in use.
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Nov 28, 2010
I want to create a class is it where I can do...
[code]...
How do I do this? Do i create a class and create a instance of CarData? but how do I add Color and Year etc to it?
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Dec 13, 2009
I do not want a Windows Media Player control on my form. I am making an alarm clock. I have tried this: Friend WithEvents WindowsMediaPlayer As New Microsoft.Win32. But I do not see a Windows Media Player member. I also asked on the MSDN VB Forum.
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Jun 11, 2012
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?
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Feb 24, 2010
I 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]...
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Aug 3, 2011
Do I have to instantiate description every time for different method? Or should I use static? Here's how I'm doing this now: What is the best way of handling this kind of situations. it seems that I repeat this line:Dim description As BLLDescription = New BLLDescription() without any good reasn.
Protected Sub Button8_Click(sender As Object, e As System.EventArgs) Handles Button8.Click
Dim description As BLLDescription = New BLLDescription()
[Cdoe].....
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Mar 31, 2010
I am trying to compile the following code and i am getting the error[code]...
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Jan 13, 2011
I have an application that reads another processes memory.I initially had multiple scanning threads for the various areas I needed to read.This was processor intensive so I decided to go with the observer pattern.All was well except that I am having a weird behavior.Here is what is happening.I have 2 radars (overlay and mapped)Both have a watcher class that attaches to the memory scanner and is notified on a new list of mobs.so I open radar 1 (mapped) it attaches it's watcher to the scanner and waits for mob list update notifications
Open radar 2 (overlay). same thing happens and another watcher is attached.all is well and good so far.Now there are properies on the mobs in the list, one of which is IsFilteredOut.This property is set in the radar code after it receives the list. Now the weird behavior is that no matter what I do, the second radar to be opened changes all the properties of the mobs in the list of both radars.It is as if I am passing the list by ref, but I am not.I actually create a new instance of the moblist class every time I pass the list.Here is the notify code. As you can see I create a new instance of the moblist class each pass.
Private Sub NotifyMobListUpdated(ByVal Mobs As List(Of MobData))
If Mobs IsNot Nothing Then
For Each w As Watcher In _watchers[code].....
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Sep 29, 2011
I 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.
[Code]...
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.
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Feb 19, 2009
I'm creating what I believe is an mdi app.I have a login form.I have a class for security.My login form creates an instance of the security class. There are all kinds of security parameters for each user (permissions to different things, etc.)These parameters are part of my security class.Once the user logs in, many other forms will all be opened and closed within the main mdi frame.All of these other forms need the information of the security class to know what the user has permission to do.Do I have to create a new instance of security class for every form in my project? Isn't there a way to store this stuff globally somehow. Retrieve once from the db at the start of the app during login and just get it from this global area everytime?
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Apr 24, 2011
I have this class Framework.Asd.Human with a public empty constructor. and i want to be able to dynamically create an instance of it from a string input "Framework.Asd.Human". Is this achievable? (in java and C#)
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Apr 6, 2009
I have a class inside a class.I need to expose the properties of the 2nd class to other classes, therefore it is public.However, I do not wish other classes to be able to create instances of this 2nd class, it should only be instantitated from its parent class.I thought I could resolve this issue by making the constructor of the 2nd class private, but this even prevents the parent class from instantiating its child class! How can I work around this, do I have to make the constructor public and allow anybody to create an instance of the class?
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Jan 14, 2009
Is it possible to create a new instance of the webbrowser class inside of a worker thread?
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May 8, 2012
I have created a class (pasted below in case I did something wrong) for which I want to create an instance that is usable across forms/modules. I can create an instance of the class in a single form/module no problem via DIM User as New User but how do I go about create a public instance accessible from all parts of my program?
[Code]...
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Apr 17, 2010
I would like to define a class as something like a constant, and use the class directly rather than having to always create an instance. Is this possible? I've tried a handful of combinations of syntax, but nothing I've tried lets me do what I'm after. To give an idea of what I'm after:
[Code]...
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Apr 25, 2012
is it possible to declare a new instance of a class using a name contained in another varible which is unknown?
For Instance....
Dim Clients() As String
Then say two clients are connected that array may contain the following:
Clients(0) = Client1245
Clients(1) = Client4856
I now need to create an instance of my class 'clsClient' for each client connecting so my thought was to declare it using the clients unique name/number. I know this isnt valid code but as an example
Dim clients(0) as New clsClient
So I would then have an instance of clsClient called Client1245 and if I had a routine in clsclient called for instance StartClient() i could then do
Client1245.StartClient()
Yes I know the code isnt valid but I think it gets across what I am trying to do and hopefully one of you smartass's will be able to instruct me on what I am trying to do and hopefully not too complex :-)
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Feb 2, 2010
Whats the best way to instantiate a class so that i can have access to the object from diffreent forms and classes?
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Dec 8, 2009
I have a form that creates an instance of a New Class. The code is simple so there is no issues with the programming.
I can step through the code on the Main Form without issues. Stepping Into moves from 1 line to the next.
I can't seem to debug the code within the class though. I set breakpoints but "stepping into" doesn't work. The code gets executed, but it doesn't step through each instruction.
I've tried changing many of the options within Tools > Debug with no luck.
I've tried deleting files from bindebug and obdebug.
Not being able to debug my programs.
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May 30, 2012
I have a Public Class named UserData which consists of Login and Password properties, as well as various permissions related properties.
I declare an instance of this class in a Public Module (named DatabaseFunctions) as
Public User As New UserData Functions in that module are able to access the instance as expected. How do I access said instance from outside of the module?
Until now, I've only needed to utilize the information within that instance from within the module, so I didn't realize that I wasn't able to access it externally. Now, I need to display data contained in that instance on a form.
I had assumed I would be able to use User.Login outside of the function in which it was declared, since everything was declared as Public, but it seems I was mistaken.
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Nov 18, 2009
is it possible to use a dll in my project without having to create an instance of the dll? for example I have a dll that has three basic math functions:
[Code]...
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Sep 23, 2009
I have 3 controls sharing the same Bindingsource.Each control will require a different parameter for the query call to the DB to populate the proper controls data.However each control is filled with the same data and using one ctrl has the same effect to the thre controls. The controls all mirror eachother.how can i create a new instance of the table adapter?
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Apr 13, 2010
VB is telling me to use the "NEW" keyword to create an object instance. For example: Private Sub ScoreTotal(ByVal sender..., ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged
[Code]....
When I run the "MainStudentScores" form and click on a student with three scores separated by the "|", it should give me a Score Total, Score Count, and Average. However it is giving me an error message at "Scores.Add(intPlaceHolder)" This is where VB is telling me to use the "NEW" keyword. Does this make sense?
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Feb 3, 2011
Namespace MyClassLib
Public Class MainClass
Public Sub New()
[CODE]...
Is it possible to make it so that the user using the Class Library has to declare a new Instance of MainClass() before using Subs/Functions in Class2 or Class3?
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Jun 7, 2012
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?
[Code]...
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Jan 18, 2011
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:
[Code]...
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Aug 19, 2009
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 ?
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Aug 19, 2009
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
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May 6, 2010
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.>>
[code].....-2138214fdeb4
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May 18, 2010
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".
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Jan 20, 2012
Is there a way to define a class such that there can be only a single instance of that class?
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