I am struggling to do what i want with classes at the moment as they are killed off at the end of a method, can somebody let me know how to make the classes live until i tell them to die? so that i can create one and refer to it from another method at another time? For example On form load i create a class Dog.Then later on i want to get info from the Class Dog. But it is no longer instantiated
View 6 RepliesHow to make my class NotInheritable but Inheritable from within the library scope (friend)
View 5 RepliesIf I declare my object at the beggining of my page class, and instantiate it in a dropdownlist selected_index change event. Shouldn't this object be available thru out the entire page and also persist thru a postback? I lose the object in my selected date change event in my calendar.
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how to declare scope for variables outside their class?
Here's what i have in a class known Create_User:
Public Class Create_User
Public conn As New SqlConnection(My.Settings.HotelConnectionString)
Public usercmd As SqlCommand
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How can i increase the scope of these variables to be used in another class? I dont want to keep declaring them again and again.
I have a complex Regex which is used to help strip out HTML from user input. I'm aware that .NET caches static Regex calls to some extent, but this one is big and used frequently, so I'd like it to hang around.[code]...
View 1 RepliesBelow is example code of what I want to do:
Public Class Test
Sub New()
Dim cool As New B
cool.Doit()
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I want to create a new instance of a class when I click on a button, but I need to interact with members of that class using other controls on the form, so I need the class to have a global scope. I know I could call the new class in formload, but the class creates certain variables that need to be current. If it is done on formload, the variables wouldn't be current, because if the class is created at formload, it would have different info at that time. Surely, there must be a way to create an instance of the myClass from within a sub that is accessible from other subs of the same class.
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Once time, me needed to compile the library with different code inside class which determined with prroject wich inherits this library At first I tried in project declare #const and in library to use condition with #const,
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I am utilizing a centralized class object that needs to call another class object. The program itself will do something like the following
sFieldValue = CentralObject.ObjectHandler(1, TestFunction, "FunctionVar,FunctionVar2,FunctionVar3")
In the central object I have a function
Public
Function ObjectHandler(ByVal ObjectType
As
Integer,
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I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
Using vb.net 2008.I have used the "Using" keyword before in C# with objects that implement iDisposable.Can you use that keyword in vb.net also? What are the advantages of the "Using" keyword other than showing the coder when the object goes out of scope.I am under the impression that the "Dispose()" function is called at the IL level when you use "Using" instead of, for examplel, calling the Dispose() in the .net code.
View 1 RepliesHere is the structure that I have:
Friend Class StandardFormatFile
Friend fileType As String
Friend numberOfSeries As Integer
[code].....
I have some classes, BsfciFile and StudyFlashCard. Bsfci is the extension to which I save my set of flashcards in an INI format. I am currently working to transform my code from using Windows API calls to access the INI to using a IniFile class that I found on the internet. I would like the BsfciFile to have a Array of StudyFlashCard objects, but I would like the StudyFlashCard class to use the IniFile class object contained in the BsfciFile class. I can pass the IniFile from the BsfciFile class to the constructor for the StudyFlashCard class, but I want it to modify the same IniFile as the BsfciFile class has later on.
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I am trying to create an list or an array of a class.Here is my "Ingredient" class that I am trying to create a list of:[code]In my "recipe" class, I am want to create a list (or array) and I am drawing a big blank on how to do it. Can anyone point me in the right direction?
View 2 Repliesdim 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'd like to have something like:
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i've created bunch of classes. i have webservices which reference these classes and contains the classes as parameters and return objects.when i call the weservice, i have to convert the class to the webservice object else i can type conversion error.is there a generic way to convert between these types without having to assign the values by hand?
for example
public class person
fname as string
lname as string
end class
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i would liek ot be able to call the web service and return the data type back and have a generic coversion instead of as above in stead of:
dim wsPerson as wsReference.Person = ws.getperson()
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 we are within the derived class then ofcource we can use MyBase keyword to access base class's object reference . That's fine , how can we take that base class's object reference outside that derived class's definition.My following code will explain what i want . Actually that is giving error right now, but it is explaining my requirement .
Public Class Base
Public x As String
End Class
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Actually there is error in ReadOnly Property BaseReference's Getter . Error is "Error 1 'MyBase' must be followed by '.' and an identifier. " how can i get base class object reference in Main method ?
If my namespace is Company.Application.EDI.Acknowledgement and if I stick with theprogramming practice of one class per file then should my class be saved asacknowledgement.vb? Are there any gotchas that will come up?
View 5 RepliesI have a Parent Class Called Fuselage that containsfour child classes called Forebody, CenterBody, AftBody, and CrossSection. CrossSection classcontains objects common to Forebody, CenterBody, and Aftbody (example: width). How do I access thewidth property in CrossSection from within the classForebody?
Public Class Fuselage
Dim Forebody As ClsSection
Dim Centerbody As ClsSection
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I am developing an IT Asset Tracking application using VB 2005 and SQL Server 2005 Express edition. Will I need to create classes to represent objects such as Computers, Printers, Scanners/Faxes, Contracts, Purchase Orders etc or are there any other approaches.For example, if I am correct, I will have a class called Computer and its properties will include Make,Model,CPU,Hard Disk,Memory etc. Is this the right approach.
Computers can be split up into Desktop PC's, Servers and Notebooks. Would I have to create separate classes for these as well or would they be ok under the Computer class.Once I create an object from the class, how can I use the object to interact with the SQL db.I am a beginner to VB.NET 2005 therefore I am slowly getting to grips with OOP.
I can't make difference between public class and private class and friend and protected friend class.
View 1 RepliesOk i need to make an object in this case a picture box draw a line to another picture box with the shortest length while avoiding other type of objects such as labels i am not sure how to do this but so far i have come up with
Private Sub ProgressBar1_ParentChanged(sender As Object, e As System.EventArgs) Handles ProgressBar1.ParentChanged
If ProgressBar1.Value = 50 Then
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bare with me during this silly example. :-) Let's say I have a class like this:
Public Class Animal
Public iLegs as int32 ' Number of legs
Public bWings as Boolean ' Wings? Yes/No
End Class
And another class that inherits the "Animal" class and adds one more property:
Public Class ScaryAnimal
Inherits Animal
Public iScariness as int32 ' 0-100, how scary is it?
End Class
Now, if I have an instance of "Animal" with some values in it, and I decide I want to cast it to a ScaryAnimal for some reason, how do I do that without having to create a new instance of "ScaryAnimal" and copy each property value?Basically I'm looking for a way to do this, without having to write the lines marked with '*** below:
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If you want a instance of an object to be created when a form loads or another class is created, you have two options:
Public class example
private IAmAObject As IAmAObject
public sub new()
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Or like this:
public class example
private IAmAObject as new IAmAObject
public sub new()
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I always use the first one. It's more type work but I think it's neater. How about you people and is there any real difference between the two?
Each business object has a matching object that contains sql calls. I'd like to restrict these sql objects in a way where they can only be used by the matching business object. How can this be achieved?
Update Greg brought up the point about testability. Since the SqlObjects will contain very business-process specific sql I don't want them reused in multiple buiness objects. (Basic CRUD operations are all code-generated) Is there a way to make the SqlObjects accessible to only one business object in the business assembly (like yshuditelu and Greg Beech showed) AND expose the SqlObjects to the unit testing assembly?
I am New to <acronym title="Visual Basic">Vb</acronym>.Net. this is my first test. i try to create small address book. but i don't know what wrong. it compile perfect but when it run it give error and not work. is there any other way to add same class like in class inside array?
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Public Class form1
Private Sub btnAnswer_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAnswer.Click[code]........
how can i make vb realize that the side that is opposite of the given angle, has to be less than the other sides. Also im not sure what Acamar meant by If txtAngleA.Text <> "" AndAlso txtAngleB.Text <> "" AndAlso txtSideA.Text <> "" Then 'two angles and a side Because im not sure what <> does.
if I put controls on form1 like button,textbox....etcwhy called this control fields not object in the class diagram ?
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