Creating Custom Generic Class?
Jan 1, 2011 Here are essential excerpts for the code creating the class and the page using it:
Imports System.Collections.ObjectModel
Public Class Test (Of T as xyz)
Inherits Collection (Of T)
[code].....
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Add Custom Class To A Generic List?
May 10, 2010I created two classes. One class is StudentClass and the other is HomeroomClass. The HomeroomClass contains a readonly property as a generic list of the StudentClass. [code]...
View 6 RepliesOverload Operator In Generic Class With Generic Interface Of Super Class And Inherit Class?
Jan 21, 2010I can do this without problem.
Class A
End Class
Class B : Inherit A
End Class
Dim Obj1 As A = New B
Alter Items Added To Generic Collection (as Property Of Custom Class)
Jun 19, 2009I have several custom classes in a VB.NET (VS2008) project which are related to each other through generic list collections. The lower tier classes refer directly to some of the parent classes (to make it easier to refer backwards up the chain). My question is, is it possible to add the reference to the parent class when the item is added to a collection, when that collection is a property?
Below is some sampling of code to illustrate.
Public Class FlexServer
Private m_FlexLicenses As List(Of FlexLicense)
Private m_Modules As List(Of FlexModule)
Public Property FlexLicenses() As List(Of FlexLicense)
[code] .....
In the code above I have the FlexServer class which refers has two lists as properties, one for FlexLicense and one for Modules. The FlexLicense class has a property to refer back to the FlexServer class that "owns" it. In order to update this property in code, I have to add the FlexLicense to the FlexServer.FlexLicenses list AND set the FlexLicense.FlexServer property. What I am looking for is, is there a way (in the property definition or wherever) to both add the item to the list and alter it at the same time?
Creating A Custom Entity Class(object)?
May 13, 2011How would I create my custom Role class based on that autogenerated class? I have read a few articles on the net but I am still lost. Can someone please show me how to do this, and what I must import(using visual basic). I want to add some validation to the string property where Role1 cannot be more than 50 characters.
Autogenerated class
[Code]...
.net - Can A Generic Version Of A Derived Class Override A Base Method Using The Generic Type
Apr 13, 2012Consider:
Public MustInherit Class Column
Public ReadOnly Property ReturnSomethingUseful() As Object
Get
'return something useful
[code]....
But this gives the following error:
Public Overrides Function ParseValue(sValue As String) As Boolean'
cannot override 'Public Overridable Function ParseValue(sValue As String) As Object'
because they differ by their return types.
I accept that you can't do this, but I'd like to be able to preserve the semantics of what I'm. trying to do, which is to have an untyped version that deals with Object, but a typed version in derived classes that knows about the specific type T.
.net - Creating A Generic List Of A Generic Type
Jun 30, 2011I am trying to create a list of a generic type in vb.net 2.0 framework.
This is the generic type definition:
Public Class GenericParamMap(Of T)
Public Sub New(ByVal pParamName As String, ByVal pPropValue As T)
mParamName = pParamName
[Code]....
The compiler does not allow a "T" in the method's parameter because it's not defined, but I'm not sure how or where to define it. I thought it was okay to have a generic method definition.
.net - Determining A Generic Type At Runtime In Non-Generic Class
Aug 14, 2010I have a Journal that records entries for different types: Journal(Of ParentT)
[Code]....
Construct A Generic Interface Class With Generic Functions
Nov 25, 2011I am trying to construct a generic interface class with generic functions. My goal was to use this to implement multiple worker classes for database interaction that have the same basic functionality. Each class will deal with different object for example, category, product or supplier but unless the the functions in the interface are generic that this won't work.This is the interface code that I have but I don't know if I have done it correctly. [code]
View 2 RepliesMake Stand Alone, Custom Web Browser (with Custom Errors, Or Generic)
Dec 13, 2011Cookies to be stored in folder and on close delete the cookies The ability to watch youtube vids, view images, and play js/flash games good security, no ads?
View 6 RepliesCreate A Custom Class That Has Inside An Array Of Another Custom Class?
Jan 31, 2011I want to create a custom class that has inside an array of another custom class (see my code below) but when the programm runs is crashes. Why? What is the right expression???? Plz help I'm a newbie in VB.net.....
Public Class ctrarray
Public nameclass As String
Public ctrlindex(glvar_spaces) As ctrlindexclass
End Class
[code]....
Way To Implement IComparable (Of T) Or IComparer(Of T) If Class Is Not A Generic Class
Feb 19, 2010I am working on a general helper class to sort ListView SubItems. I wrote a base class that has much of the code I need. It includes a MustOverride for the Compare method so that the various inherited classes can implment their own comparisons based upon their type. For the value types, I end up with very similar code such as the following, where x and y are ListViewItems: Public Overloads Overrides Function Compare(ByVal x As Object, ByVal y As Object, ByVal sortColumnIndex As Integer, ByVal sortOrder As System.Windows.Forms.SortOrder) As Integer [code]
View 3 RepliesCustom Generic.IEqualityComparer(Of T) - Compiler Errors
Jun 17, 2009I am trying to implement a simple IEqulityComparer to use with LINQ collections. I have written the following code which is reduced to its simplest form for discussion purposes...
Public Structure bob
Dim SiteID As Integer
Dim fred As String
End Structure
[code]....
The problem that I have is that both functions throw the compiler warning "function 'getHashCode' (or 'Equals') shadows an overridable method in the base class 'Object'. To override the base class method, this method must be declared 'Overrides'."
However, if I declare them as Overrides, I get the error "function 'GetHashCode' cannot be declared Overrides because it does not override a function in the base class."!!I am also getting a compiler error on the "Implements" line to the effect that I must implement "getHashCode" but I presume that is a result of the first problem.
Creating A Generic List Of A Specified Type?
May 26, 2010I want to create a generic list - but I want to specify the type at runtime - is there a way I can do this? using reflection perhaps?Something like this...
Public Shared Sub create(ByVal t As Type)
Dim myList As New Generic.List(Of t)
End Sub
Index Out Of Range Exception In Custom Generic Collection?
Feb 25, 2009I wrote a class which imports System.Collections.ObjectModel. For the management of the collection, I've written:
Default Public ReadOnly Property Item(ByVal vntIndexKey As Integer) As ItemType
Get
Return CType(mCol.Item(vntIndexKey), ItemType)
[code].....
VS 2008 Transfer A Custom Event Through The Generic Collection?
Dec 22, 2009To the point: I need to transfer a custom object's event through a generic collection object containing these items so that any class using the collection can see that changes were made to one of the items in the collection.
I.E. An item event that triggers a collection event
[Code].....
Due to the application requirements, I need the Collection and Items to send immediate notice of various changes that occur to the Collection Class and its items. I've already got my events set-up regarding for the Collection Class, but I'm struggling with coming up with a workable solution for raising events for the items.
I've got an event for the DeviceLayer item set-up, but how do you transfer that event through the CollectionClass so that any other class using it will see that there was a change to one of the items in the collection?
Creating Generic Collections And Calling To New VB Page?
Mar 25, 2011I am new to VB.NET, just landed a job fresh out of school (well still in school), but I am having trouble with VB...alot of it is getting used to the IDE itsself (we use VB 2010).t does alot of the work for you which is cool but I am having some trouble understanding some concepts.Here are my questions: How to call classes named an initialized on a DSS skeleton to a new page. And the functionalities of building a collection. (also the differences of a generic
View 5 RepliesGeneric Lists Copying References Rather Than Creating A CopiedList
Mar 8, 2010I was developing a small function when trying to run an enumerator across a list and then carry out some action. (Below is an idea of what I was trying to do. When trying to remove I got a "Collection cannot be modified" which after I had actually woken up I realised that tempList must have just been assigned myLists reference rather than a copy of myLists. After that I tried to find a way to say
[Code]...
Interface And Graphics :: Making A Custom Class That Mocks The System.Drawing.Rectangle Class?
Jul 6, 2010I'm making a custom class that mocks the System.Drawing.Rectangle class because the Rectangle class doesn't have a name property. I need a name property because I am adding all of my rectangles to a collection and I need a little more info stored than just their locale and size. So I changed the _onPaint event but nothing is working out when I run the program?
Public Class Rectanglar : Inherits UserControl
Public BackgroundColor As Color = Color.Blue
Public Sub New(ByVal name As String, ByVal XY As Point, ByVal Widthy As Integer, ByVal Heighty As Integer)
[code].....
.net - Creating A Generic Method For Converting String To Nullable Numbers
Jun 19, 2009I have 3 similar functions, that only change based on numeric type:
<Extension()> _
Public Function ToNullableShort(ByVal str As String) As Short?
Dim intReturn As Short
[Code].....
I was trying to make a generic function out of this, but couldn't do it. How can I make a generic function that will take a specific T and make it a Nullable(of T)?
Have A Dynamic URL In Generic Class?
Apr 22, 2009I need to have a dynamic URL preferably from a Test Classformatting this design pattern to handle dynamic links from tests. instead of a constant HomePageURL.
Namespace TestDesign
Public Class HomePage
Inherits IE
[code].....
Recognize A Generic Class?
Mar 19, 2010How can I recognize (.NET 2) a generic class?
Class A(Of T)
End Class
' not work '
If TypeOf myObject Is A Then
Inherit From A Generic Class Without Specifying A Type?
Apr 29, 2009I have the following sample code in a VB.NET console application. It compiles and works, but feels like a hack. Is there a way to define EmptyChild so that it inherits from Intermediate(Of T As Class) without using the dummy EmptyClass?
Module Module1
Sub Main()
Dim Child1 = New RealChild()[code].....
The other way to do this would be to move the generic code out of the Base class and then create 2 Intermediate classes like this [code]...
Then RealChild would inherit from the generic Intermediate and EmptyChild would inherit from the non-generic Intermediate. My problem with that solution is that the Base class is in a separate assembly and I need to keep the code that handles the generic type in that assembly. And there is functionality in the Intermediate class that does not belong in the assembly with the Base class.
C# - Create A Generic Method In A Class?
Apr 28, 2010I am really trying to follow the DRY principle. I have a sub that looks like this?
Private Sub DoSupplyModel
OutputLine("ITEM SUMMARIES")
Dim ItemSumms As New SupplyModel.ItemSummaries(_currentSupplyModel, _excelRows)
ItemSumms.FillRows()
[Code]...
Generic Class's Constructors With Param
Dec 30, 2009i've got a Class like this public Class Cart(Of Item) Public Sub New(ByVal a As Integer, ByVal ParamArray items As Item())but i do not see how to create an instance of it: Dim block_names As New Cart(Of String, 5I)i get something like "type expected" o.O
View 2 RepliesGeneric Error Handling Class?
Jan 10, 2012We are developing an application for our shop floor. This program will be tracking material through the shop and we need to capture any errors the program generates, but we don't need to stop the program for all errors. I have some code to do a screen capture and put it in a database with exception.tostring data for debugging.
What we would like to do, is create an exception from the base class, but provide additional properties to allow us to set a severity and a user friendly error message. I would like to encapsulate this in a class that we would call in the catch of a try/catch, set the properties on the class, have the class record the data to the database, then raise the exception to the main program to display only the user friendly message and severity. The main program would then determine the severity and based on the severity stop the program or just display a discreet msg and continue to process.
Does anyone have an example of a custom exception class derived from exception that does something similar, or if I heading in the wrong direction, does anyone have a better solution?
Generic Inherited Class Definition
Jan 11, 2010I'm having trouble with the definition of an inherited generic class. I have two base classes that are defined like this:[code]
View 2 RepliesGeneric List Class Cast?
Jun 10, 2010how Inheriting List(of T) should work.It seems like what I have below should work but at runtime I get the error:[code..]
If I want to cast a List(of x) to the class xlist, how should I do that?[code...]
How To Load A Generic Class Without Loop
Jul 15, 2010ok this is the thing I have right now which is working quite well beside its a bit slow:
Public Function GetList() As List(Of SalesOrder)
Try
Dim list As New List(Of SalesOrder)
Dim ds As DataSet
ds = cls.GetSalesOrderList 'CLS is the data access class
[Code]...
Implementing Generic IComparer Of Own Class?
Jun 17, 2012I am trying to create a class implementing the generic IComparer of my own class "Stellungen" (which translates to positions, like on a chess or checkers board).
This is what I got:
Private Class comparer(Of Stellung)
Implements System.Collections.Generic.IComparer(Of Stellung)
Public Function Compare(x As Stellung, y As Stellung) As Integer Implements System.Collections.Generic.IComparer(Of Stellung).Compare
End Function
End Class
Problem is: inside the function I have no access to any fields of my class. If I start off with x. Intellisense will only give me .Equals, .GetHashCode - the methods you get on a type but not on an instance. Visual Studio 10 also highlights this, in the definition of the function the bits "x as Stellung" and "y as Stellung" are written in light blue, meaning it is a type and not an actual object. How do I access the things I want to compare inside my class?