I have a base class which needs to define an enumeration:
BaseClass
- SomeEnum
I then need to create two derived classes from the base class and extend the values in the enumeration:
ChildClass1 : BaseClass
- SomeEnum
- SomeEnumValue1
[code]....
In C# or VB.NET can someone provide the syntax to do this?
I have an class named Foo. This class contains a collection of child objects of type FooChildBase, but I also have a further class of type FooChildTwo which inherits from FooChildBase.
Class Foo
Public Children As IList(Of FooChildBase)
End Class
Class FooChildBase
[code]....
What I would like to do is have my FooSpecial Class treat it's Children collection as if they were FooChildSpecial objects, but still be able to add FooChildTwo objects to it. Is this possible and if so how can it be done?
EDIT:I need to FooChildSpecial class to wrap any of the objects in the Children collection with the extra values, whether they are FooChildBase or FooChildTwo?
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
[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 ?
When you create a webpage in ASP.net, the codebase inherits System.Web.UI.Page Now when I extend the page object to check for SessionExpired for example, I create a new class and inherit from system.web.ui.page, and overwrite some functions. The problem then is that on each page, I have to replace system.web.ui.page with my custompage class. Is there a way to extend a class by adding methods or modifying its methods directly (e.g. add the sessionExpired check to System.Web.UI.Page) ?I'm using .NET 2.0
View 2 RepliesI have a class within a library, with no root namespace, firstone.dll:
namespace first
public partial class one
public sub fun()
[Code]....
Is there a way to extend the class in a separate dll and still have access to the original class? I don't want to inherit the class just extend it.
I have to create an XML database for a class I'm taking, but I'm running into some problems. I'm trying to pack my data directly into the DOM using some classes I created and derived from the XMLDocument class, I'm trying to do it this way so I can easily manipulate the entries while the document is in memory and save them back to a file without having to mess around too deeply with the XMLDocument class. I'm running into some problems however when I try to typecast the elements I get from calling
Code:
XMLDocument.DocumentElement.Item
I assume that this is happening due to my derived class not being pushed into the DOM when a file is loaded, because it works just fine if I enter the data manually in code.
Code:
Option Explicit On
[CODE].............
Other than writing my own XMLReader I have no idea how to accomplish this, does anyone have an idea how I could go around doing this(other than writing my own XMLReader).
I would like to add a property to the BoundField control that will change rendering as show below.
<td>My Bound Text></td>
Should become
<td><span>My Bound Text</span></td>
This is all I have so far...
Public Class BoundField
Inherits System.Web.UI.WebControls.BoundField
Dim _ellipse As Boolean[code]....
I have the same problem as this poster, however I am using a .net gridview and would like render my html to use the fix offered here.Using CSS to create table cells of a specific width with no word wrapping. EDIT I think I may be going about this all wrong, maybe you don't change the rendering by extending the BoundField, but rather add the properties to the boundfield then change the way the gridview renders its fields based on the properties of those fields.Which also leads me down the path of control adapters,
I have a form event that calls a public function in a class. I am trying to use an enumeration that is in the class from my form, but I'm getting a green squiggly line under clRS.enmProcedure.SetReady.
The error says this:
"Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated."
Private Sub dgvResults_CellContentClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgvResults.CellContentClick
If clRS.pubfnc_UpdateResults_M(dtResultID, Me.dgvResults, clRS.enmProcedure.SetReady) = "Failed" Then
Exit Sub
End If
End Sub
I have a class definition that I've seen other define properties that return collections of objects.
Public Property GetAllAdults() as Adults End Property I made the argument that this should be a method in the class, because it doesn't define an attribute of the class, and could not be extended with parameters. Is/Are there reasons why this should be defined as a property vs. a function?
How do I creat a simple array of class definitions?[code]...
View 13 RepliesI'm having trouble with the definition of an inherited generic class. I have two base classes that are defined like this:[code]
View 2 RepliesI'm working a business layer (separate assembly) that will contain various business entities used in multiple client applications. One of the client applications is a WCF app that will need to serialize these entities. In order to properly serialize the entities, metadata for data contracts or for XML serialization must be added, but the serialization requirements may vary across applications.
Clearly I need the metadata separated from the class definition. So how do I add metadata to my entities for each separate application?
I call upon the VB ninjas out there. Here's my situation. I need to eventually be able to pass multiple models to a view. Currently I have a linq to sql class that, of course, has a bunch of generated model definitions. I need to make a model that implements multiple models. I somewhat understand how to do this in C#, but this project is testing my VB skillz. Here's some snippets from my linq to sql models. I need to combine these two into one model to pass to the view.
[Code]...
In order to organize various methods of my MainForm class, I would like to categorize them into several files. Of course, the methods would still need to access form elements and additional variables I added in the MainForm class.
View 3 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 .[code]...
I see a sample code that an object is instantiated within the class definition block. But when I test the folllowing, I got error "Process is terminated due to
[Code]...
I am currently using reflection to retrieve all properties of a class. I return a collection of PropertyInfo objects and all is working fine.
My problem is, I want to check if a property has been defined in a base class implementation and is therefore inherited in the current class.
I have 3 classes that need themselves in order to do their work but if I declare them the old way it would end up being an endless loop.
As an ex C++ programmer, I know I could use include once but I don't know if there is any equivalency in vb.net Here is the picture.
I have 3 Classes : SQLConnector, ErrorHandler, LogHandler
- ErrorHandler needs SQLConnector to get some IDs from the Database.
- ErrorHandler needs the LogHandler class to prepare the Logs to be... logged.
- SQLConnector needs the ErrorHandler class in case there is errors happening.
- LogHandler needs SQLConnector to insert in the database.
- LogHandler needs ErrorHandler in case the insert is not successful (sends mail in that case)
As you can see, all three classes are needed. The reason why I can't use LogHandler and ErrorHandler as one class is that I will use that class to log transactions and changes according to some parameters. Log is in no way exclusive to ErrorHandler.how I can prevent to make an endless loop and use all three of them as I wish?
In a global module, I define a new type that can take 4 values:
enum tAction as integer
None
Update
Insert
Delete
end enum
A use this type in many places in my code to check the value stored in a variable (if MyAction = tAction.Delete then ...)
In a separate file, I define a class. One of the properties should return a value of this type:
public class XXX
private _Action as tAction
public property ClassAction() as tAction
[Code].....
This way I could check a class property in the same manner (if MyClass.ClassAction = tAction.Insert then ...)
However I get a syntax error in the property definition: 'ClassAction' cannot expose type 'Globals.tAction' outside the project through class 'XXX'
My entire program consists in a few modules, in a single project. How can I use my tAction definition in my classes?
I have just received an interesting feedback from a VB.NET customer using our product - for some reason intellisense hidden a certain enumeration value.After a small testing I have found that this is likely a bug in IntelliSense: [URL]..To be honest, I did not expect this problem with such a basic stuff like this. Have you seen this in the past? For me, it doesn't work in all VS versions...
Anyway, feel free to track this issue if you are coding in VB.NET.
I'm trying to return code like this (can be found here):
{"hotspots": [{
"id": "test_1",
"anchor": { "geolocation": { "lat": 52.3729, "lon": 4.93 } },
[code].....
Can you define this :
Class
Object
Inheritance
Polymorphism
Abstraction
And could you make it easy to understand I'm having a hard time to understand those terms.
i was trying to inherit System.Type. this is what i have:
[Code]...
and anyway the real problem is that inheriting System.Type without declaring my derived class as 'MustInherit
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 RepliesI have Class1 and class2 which is inside class1, VB.NET code:
Public Class class1
Public varisbleX As Integer = 1
Public Class class2
[code]....
I have a 'property management class' that contains several functions and properties. I have several other classes that use the 'management class' as a property to derive the value of several of its other properties.Is there a way for me to reference the outer class from the 'management class' functions without having to pass it as a parameter? I ask because several different classes can have this 'management class' as a property and am having a hard time typing the parameter.
View 7 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 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
[code].....
I have a problem that is frustrating me to no end, I have a overrideable function in a parent class, and the override function in the child class, like below:
[Code]...
When i debug, the value is produced, but it doesn't carry over to the parent class of ski.RetailPrice()what seems to be the problem here?
I need to display data from many tables using a datagridview and I was wondering if this can be done using the JoinView class.I have used it before, but with one child table only. Now I have more child tables and I was wondering which approach (if many) would be the best.
The Dataset I am working with contains 28 relational DataTables but I only need 10 or so for the query, and they are structured like this[code]...
