I have a class structure and am attempting to create an array of object instances from the class some instances are parents and some are children Code snippets,
Parent Class object
Option Strict On
Option Explicit On
Public Class cTransportItem
[code]....
info on creating instances of my own class at runtime. Simple project for family recipes but would like the option to add new recipes with new instances of my own food Item class at runtime. Creating my own class,no problem. Storing the data in an XML file, OK on that as well. My issue is creating new instances of different food item class as I use this program over time
View 13 RepliesWhat is an elegant way to create and initialise instances of a class that has several readonly properties? Passing all values in a constructor would not be very convenient.
The purpose is that instances are immutable after initialisation. However if the constructor is not used for initialising all the property values, then how can the readonly properties be changed from another class?
In our application, we have a number of Windows Services (more than 30) that must run behind the scenes to process data at given times throughout the day. I was attempting to create a BaseService class that I could inherit from that would log to our database when the service started or stopped as well as some other common functionality. However, I ran into a show stopper in trying to create BaseService as MustInherit as we have a number of MustOverride properties. The issue lies in:
<MTAThread()> Shared Sub Main()
Our code is all in VB (as you can probably tell). Given that it is a Shared method, I cannot have it be overriden (i.e. make it MustOverride). Without this method, the code will not compile, however it will not really work in the base class. The code in this method is:
Dim ServicesToRun() As System.ServiceProcess.ServiceBase
ServicesToRun = New System.ServiceProcess.ServiceBase() {New BaseService}
System.ServiceProcess.ServiceBase.Run(ServicesToRun)
The BaseService (the name of my base class) cannot be created because it is specified as MustInherit. And therein lies my problem. I cannot create this in the Base Class and cannot override it in the inheriting classes.
I have an array of objects 2000 that are instances of a class. I want to alphebatise these objects by a detail of the class.
View 1 RepliesI am writing a game editor, and have a lot of different "tool" objects. They all inherit from BTool and have the same constructor. I would like to dynamically populate a toolbox at runtime with buttons that correspond to these tools, and when clicked have them create an instance of that tool and set it as the current tool. Is this possible, and if so will it be better/easier than creating those buttons by hand?
View 3 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 Repliesmy aim is to create a new instance box at the push of a button, the box has strings name and Id to be filled concatenating the auto generated ID i.e. 0 to 210 plus a string "Box" added by the user. I had problems earlier creating a structure within the class box, frankly I am not sure if the code below will work, as i try to run it in VB I get an error indicating that I am using the variables strBoxPositions() and strBoxNumbers() without assigning a value to it. The thing is the strBoxPositions() should automatically be filled by arrPosition() which will be created at the same time the new object box is created and the strNumbers() will be created with empty strings to be filled at latter stage by the used as and when necessary.
how could I initialise those arrays to get the program to run and perhaps ill be able to see if the code works or not, or just correct this code with a better way of code with comments, also if possible some indication on how could I update the strNumbers array inputing the strings one at a time on a text box field.
Public class form1
Public Class Box
Public intBoxID As Integer
[Code].....
In VB.net we are creating different namespace level classes. For Example,DynamicPDF - Root NameSpaceTest ,Report are two sub folders in side the sub folders some classes.
1) DynamicPDF.Test.ClassA
2) DynamicPDF.Test.Report.ClassB
using the VB.NET i was generated the Tlb file.
[code]....
I am trying to copy a byte array into a Class that is in a third party library
Dim usr As New RSI_USER_RECORD Dim ba(RSI_USER_RECORD.RSI_LEN_USER_REC - 1) As Byte 'populate ba here usr = ba 'how can I do this? Is this even possible?
Here is the definition of the class (from Reflector)
[Code]...
When I do this
Public Class cInherits : Inherits Panel
I get this: Base class 'System.Windows.Forms.Panel' specified for class 'MenuButton' cannot be different from the base class 'System.Windows.Forms.UserControl' of one of its other partial types.
How do I inherit?
How can I create an array of a class that I have declared? I have this class named partswith properties of frame, engine and date, and i want to know how could I store them in an array .
View 1 RepliesI have put this code in the global form Inherits System.Windows.Forms.Form. And then in the form that will inherit this from the global Inherits MenuStrip. "MenuStrip" is what the global form is called. But keep getting this error: Error1Base class 'MenuStrip' specified for class 'Lesson2' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types.
View 5 RepliesIt's been a LONG time since I messed with VB, and I'm messing around with VB 2008 now.I'm trying to make a custom class with three variables,
ID (String)
Title (String)
Comments (Array of String)
[code]......
I have set the "Make single instance application" check box.And when my application version is 1.0.0.0 for example, it is OK and won't load multiple instances.But when I create a new version, for example 1.0.0.1, then I can run 2 instances of my application, when the 1st instance is 1.0.0.0 and the second instance is 1.0.0.1.What should I do to prevent this?
View 2 RepliesI have created a class for a Sports Facility. A facility has a Name, Status, Notes, etc as members of the class. This works well, I can create a new instance of an exisitng Sports Facility from the database, create a new instance, etc. All working well.What I am stuck on is accessing a list of Sports Facilities. I know I can create a new list by doing
Dim List As New List(Of Facility)
For Each fRow As DataRow In ds.Tables("Facilities").Rows
List.Add(New Facility(fRow.Item("FacilityID"))
Next
I'm retrieving data from Excel and would like to keep my arrays 0 based but Excel returns 1 base. Is there a fairly simple way to return change the array from 1 to 0 base? Or do I just need to create a loop? Here's an example code right here:
[Code]...
Here is the structure that I have:
Friend Class StandardFormatFile
Friend fileType As String
Friend numberOfSeries As Integer
[code].....
I've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
[Code]...
Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
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I would like to be able to set Control visual properties such as color, boarder, flat style, etc. on the base class of the control so that as I add new instances of the control, each instance inherits the visual properties of the base. I have tried using Application Settings but it appears as though I need to reference an application setting manually each time I add the control to a form. This is a Windows Form question.
View 4 RepliesSupose a base class
Public Class airplane
Private var_num_seats As Integer
Private var_num_engines As Integer
[code]....
Obviously, I don't wish that the class Glider has the method "start_engines" neither the property "num_engines". Otherwise, other child classes may have. How can I supress these property and method in child class, not just ignoring (if I can)?
I am trying to create a class in VB.NET which inherits a base abstract class and also implements an interface. The interface declares a string property called Description. The base class contains a string property called Description. The main class inherits the base class and implements the interface. The existence of the Description property in the base class fulfills the interface requirements. This works fine in C# but causes issues in VB.NET.
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This is another one of my "I think it's not possible but I need confirmation" questions.I have a base class for a bunch of child classes. Right now, this base class has a few common properties the children use, like Name. The base is an abstract class (MustInherit)Technically, this means that everytime a child class is instantiated, it lugs around, in memory, its own copy of Name. The thing is, Name is going to be a fixed value for all instances of a given child. I.e., Child1.Name will return "child_object1", and Child2.Name will return "child_object2".
View 1 RepliesSuppose I have piece of code like this:
Public Interface ISomething
....
End Interface
[code]....
I suspect I am being very silly here but I have the following setup
Class MustInherit myBaseClass
'some stuff
End Class
Class myInheritedClassA
[code]....
Running this results in the following error
Unhandled Exception: System.InvalidOperationException:
There was an error generating the XML document. --->
System.InvalidOperationException:
[code]....
is there any way of 'Widening' the inherited class to the base class so this would work?
EDIT:regarding XmlInclude(typeof inheritedClass), currently this method could potentially return a number of types of inherited class (i.e myInheritedClassA and myInheritedClassB) is it case of simply having to add each of the inheritedTypes in this tag?
I'm trying to create 3 instances of the the Workshop selector form for the 3 individuals that I have inthe listbox to appear when I first run the program.
View 4 RepliesHow do I access the base class inside a derived class?
View 1 RepliesIf 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
[code]....
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 ?
I have a form (form1) and I havea button on form1 (button1) that will start a second form (form2).How can I make it create multiple instances of form2 when button1 is clicked?i tried a process module that the studio comes as standard but it does not allow me to start multiple instances...how can i do this?
View 14 Replies