I have some question about Class I am doing all of my VB learning mostly thru this forum and via some tutorials, web searches and example programs. That being said, here I go.
From the MSDN website I came across "Creating Classes in Visual Basic"
I didn't know a Class could be created.So in your most non-technical laungage with the most layman terms posible. How would you describe a Class, Why would I need to create a Class?
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How can I dynamically initiate a "new" class?Basically I'm storing references to classes in an array and I want to create and dispose them on demand.
View 4 Replies1) Add a Private variable named _area2) Associate the _area variable with a Property procedure called Area3) Change the CalculateArea method to a Sub procedure. The method should calculate the area and then assign the result to the _area variable.4) Include a parameterized constructor in the class. The constructor should accept one argument: the side measurement. After using the Public property to initialize the Private variable, the constructor should automatically call the CalculateArea method.At this point I believe I've completed the first 2 steps for the Square method, but I'm not sure where to go from therHere is my code for the Square class and the Main Form, in tha order:
Public Class Square
Private _side As Integer
Private _area As Integer
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I'm wondering on how you would go abouts instantiating a class that contains other complex objects. for example an Payment Class which has Date,Time, etc.. and it also holds a reference to a paymethod object which has id,Type,Description etc.. How do you instantiate the payment class with all the other objects without one or the other failing, how do you create the payment class which doesn
View 4 RepliesHow would you create depth code for two classes in visual basic 2008 (like if you wanted to put one picturebox behind another picturebox depending on what each picturebox's depth equals)?[code]I can't get my movement code and the image for the character object to work.
View 3 RepliesI am using the O/R Designer to create entity classes in VB 2010. I am observing different results for different database tables that I can't explain and more importantly, can't replicate the results that I want.Using server explorer, I have dragged a number of tables on the O/R designer surface, thereby creating the entity classes.
I have saved the project and can access the various entity classes in my project code. I first noticed a difference when changes made to object instances from some tables/entity classes appeared to persist while changes made to object instances from other tables/entity classes did not persist. These object instances are created, accessed, and changed using the exact same code patterns except for the object, class and table names.
I have been looking to see if there are any differences between the way in which the entity classes are treated, either in my code, in server explorer, or in the O/R Designer. I cannot find any. The properties of the entity classes indicate that all of the classes use the runtime methods for insert, delete and update. As far as I am aware, I have not knowingly made changes to these methods.
The ONLY difference that I find is in the file NameofClass.designer.vb. This is an automatically generated document. The partial class of those objects that appear to persist changes contains different code from that of other partial classes where changes to objects do not persist.In the declarations section of this partial class, the following lines appear:
<Global.System.Data.Linq.Mapping.TableAttribute(Name:="dbo.OrderofBattle")> _
Partial Public Class OrderofBattle
Implements System.ComponentModel.INotifyPropertyChanging, System.ComponentModel.INotifyPropertyChanged
[code]....
If I am right then I want to enable persistence in my other classes by causing this additional code to be generated for them. But how? why the code for this one class hase been generated differently than for all the others (actually it is this way for 2 out of about 15 classes). What setting or or selection do I have to make to enable this code to be created for my other entity classes during the automated process?
I am learningCreating LINQ to SQL Classes: Using the O/R Designer, the link is found below[url]...But when I Step #8 of Binding Controls on a Windows Form to Entity Classes says:8. Create an event handler for the Form_Load event by double-clicking the form. Add the following code to the event handler:
View 4 RepliesI have a Clients master object and then a number of child objects whose exact number is not known in advance such as Client-Contacts, Client-Payments etc, all of which have a one-to-many relationship with the Client master object.How do I define classes for such a scenario? Do I for instance create the master Clients class and can then I create an array of class somehow for child objects?
View 2 RepliesI seem to be having a problem with controls that I am creating as new classes (not UserControls) inheriting from an existing system control. Everything seems ok while I create the control code, through to the compile (which is successful and adds the control to the toolbox) and dragging the control from the toolbox to the GUI surface. However, when I then debug or compile the project, I get a message such
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I have two classes, one nested in the other. [code]Neither "Name" or "ID" are unique between operations and records.I wish to construct a dictionary using LINQ = Dictionary(Of String, Of List(Of Integer), whereby the keys are uniqe examples of Names in my collection and the values are the collective set of distinct IDs that are associated with those names.
View 2 RepliesHow can I structure my classes so that the user interfaces though a single class while the supporting classes are hidden from their view? I think its best understood in an example:
Public Class MyInterface
Public Economic as EconomicClass
Public Sub New()
MyBase.New()
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So you might ask why am I even separating them? It's strictly for others who will be working with this interface. I need to funnel them though a logical structure:
interface.Economic.MyMethod
interface.Currency.MyMethod
etc
This way everything is already handled for them in the background and they only need to run the method they need. I don't know if I can have it both ways in VB.NET.
Here is some example code of what I mean:
vb
Public Class Form1
Private Sub Button1_Click(ByVal sender as Object, e as systemEventArgs) Handles Button1.Click
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I m trying to raise Click event of Textbox explictly but I m getting "Derived classes cannot raise base classes" error.[code]....
View 1 Repliesso far i got
code
For Each item As Reflection.FieldInfo In GetType(NameSpace.ClassWithNestedClasses).GetFields
rtfAppend(item.Name & ":" & Tab & item.GetValue(Me))
Next
For Each item As Reflection.PropertyInfo In GetType(NameSpace.ClassWithNestedClasses).GetProperties()
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which gets me the simple string vars and properties of my top class, but how can i apply this to loop through all sub classes and get there vars and props?
Searching the internet finds no less than 700 different ways and opinions to accomplish what I'm trying to do, and I would just like to know the simplest, most bullet-proof way possible.
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I simply want to extract the string "bar," which is inside <hostName></hostName>I can do this easily enough with simple string functions, but I'd like to do it with one of the .NET XML classes/methods.
I have three classes Employee, Manager and Salesman. Manager and Salesman classes inherits Employee class.
Employee :
Public MustInherit Class Employee
' Field data.
Protected empName As String
Protected empID As Integer
Protected currPay As Single
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Manager :
Public Class Manager
Inherits Employee
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Salesman :
Public Class Salesman
Inherits Employee
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Now I have created a object of salesman and manager using the following code:
Dim objSalesMan as Employee=new Salesman("xyz",1,2000,5000)
Dim objManager as Employee=new Manager("abx",2,5000,"production")
Is this a good programming pratice or should I use:
Dim objSalesMan as new Salesman("xyz",1,2000,5000)
Dim objManager as new Manager("abx",2,5000,"production")
please tell me what is below code doing? is it creating array with two values or its creating to string index which will take value later? [code]
View 4 RepliesI find that I write a lot of code within my classes to keep properties in sync with each other. I've read about Events in Classes, but have not been able to wrap my head around how to make them work for what I'm looking for.For example, in this one I always want to keep myColor up to date with any change whatsoever in any or all of the Red, Green or Blue properties.
Class myColors
Private Property Red As Byte
Private Property Green As Byte
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If one or more of those changes, I want myColor to be updated. Easy enough as above, but is there a way to work with events that would automatically do this so I don't have to put myColor = Color.FromArgb(Red, Green, Blue) in every sub routine?
How can I create a namespace and classes in it, then save it, and reuse the namespace in other projects? Do I have to click on Create Class Library in Visual Studio?
View 2 RepliesI am new to .net and was wondering if there are any projects which have sets of vb.net classes online which i can use. For example we have Flourish — PHP Unframework which has lots of php classes therefore a programmer doesn't not to replicate code on each project. Is there a asp.net (vb) resource website or any open source project which has built in vb.net functions.
View 3 Repliescreated class TestA. There is Sub mysub defined inside it. Now I want to use this Sub in other class. So far I did like this:
Dim oTestA As New TestA
Dim dblA As Double
dblA = oTestA.mysub
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I have a slew of sub routines that I need to use in my software because each website that I will be accessing don't all use the same methods.....go here...click that...go here...click that...etc etc
So I've divided them into sub routines and call them when I need them but the coding is getting so long that it's becoming confusing to keep up with each sub.
Is it possible to place the sub routines into an independent file like a class and then call them from the file when I need them so I can free up some space to code?
The 1st part of the code required me to write a class definition for a class(Worker). The class should include Private variables and Property procedures for a worker object's name and salary.
The salary may contain a decimal place. The class should also contain two constructors:a default and a parameterized.
The second part for the code indicates that I need add a method named GetNewSalary to the Worker class.The method should calculate a Worker objects new salary, which is based on a raise percentage provided by the application using the object.
Before calculating the new salary, the method should verify that the raise percentage is greater than or equal to zero. If the raise percentage is less than zero the method should assign the number zero as the new salary
There are three text boxes which allows the user to enter the employees name current salary and raise percentage....the calculate button will display the new salary in the new salary label box...so far here is what I have for the worker class.
The Class for the code had to be written from scratch. Can you please look over the class code and see if I need to chang anything....that will allow the program to run.[code...]
'A way to connect to SQL with VB.Net using Classes
'This must be a class on its own
Imports System
Imports System.IO
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How can I add c# classes to my vb project. I am using vb .net express 2008
View 1 RepliesI am trying to get to grips with Classes and how to use them "efficiently", So bearing this in mind I decided to create a small class driven application.I am struggling to understand how I can "use" this new instance of this user somewhere else.
Test Data was
Name : Joe
username : JoeBloggs
Password : JoesPassword
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Now this works and updates the listbox with the new instance of the user but how can I use that instance from the listBox control to retrieve that users details?
As easily as possible? How to parse and create XML easily?
View 3 Replieshow to write classes. I have been searching and I understand classes a little. What I am confused on is how to write a class that contains more than 1 bit of information. How would I write a class that contains someone First Name, Last Name, Age, Address, City and State they live in. For instance all the information in the class can be retreived if I enter the person last name. And the class has to have more than 1 person infomation in it.
View 8 RepliesIDE: VS2010 Framework.net: 4.0 I created a c# dll project under Visual Studio 2010, with several public classes, and I would like to use its classes inside another dll project, but written in vb.net.
In the vb.net dll project, I referenced the built c# dll, but impossible to import the c# classes. The namespace of the c# dll is even not recognized.
What must I do to see my c# classes? If this is possible.
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How do I integrate C++ into Visual Basic applications made in Visual Studio?
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