Initializing A List Of A Class?
Jul 25, 2009what the syntax is for initializing a list of a class, eg:-
Public class myparams
private myno as integer
private name as string
end class
[code]....
what the syntax is for initializing a list of a class, eg:-
Public class myparams
private myno as integer
private name as string
end class
[code]....
Why if I run the following code does the argument in the Add method pass {"foo2", "bar2"} in both method calls?
Dim myList As New List(Of String)
myList.AddRange(New String() {"foo", "bar"})
Add(New RandomClass("blah", myList ))
[CODE].....................
Is there a way to have a class collection of inherited types be initialized? For example, here is my code:
Public Class CamryCar
Property Name As String = "Camry"
Property Color As String
End Class
Public Class RedCamry
[Code] .....
I prefer this one as I don't have an extra property to deal with. But I can find a way to initialize that that list with objects of RedCamry and BlueCamry. Is it impossible or is there another way to do this?
I've got some code that looks like this:
If ediFileGroupAbbr = "NIPDSINV" OrElse ediFileGroupAbbr = "WWPDSINV" Then
Dim p As New PrivateBillingAdapter_ForN(ediFileGroupAbbr, businessLocationID, mode, EDIJobItemLogID, BusinessUnitID)
Return p.ProcessEDI(True, False)
ElseIf ediFileGroupAbbr = "FOPDSINV" Then
[code]...
to which I'm passing in a value of ediFileGroupAbbr = "FOPDSINV". But the code is executing as if it's dropping into the third condition (p is a PrivateBillingAdapter). So I've stepped into the code and, sure enough, it drops into the second condition. BUT, if I step into the execution of the constructor, the debugger jumps to an odd place in the code - sort of the middle of a method and not on any actual line of code.A couple clicks and it hops back out of the constructor, still in the second block of code. But if I mouse over the variable p to see it's type, boom, its a PrivateBillingAdapter (from the third block).Like I said, something is clearly wrong but I don't know what. I've tried rebuilding several times but with no new results.This is VS2003, framework 1.1 with VB.NET.
I am converting an old Vb6 solution to .net 2.0 in vs2010. I've been working in C# for about 3 years now and .net for 5. I don't recall having this problem in C#, but if I want initialize a readonly collection of DerivedControlFoo Is there a clean way to do it besides creating a sub to do it all off somewhere else? I'd love to be able to do it at the class level at the declaration for readability and simplicity.
View 1 RepliesI 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?
I have a base class (ex: Class1) containing a list of another base class (ex: ClassA). Each child class of first base class (ex: Class1AA, Class1AB,..) containing a list of child class of second base class (ex: ClassAA, ClassAB,...)The client must never know which child class is using, then i don't think i can use generic for my bases classes.I try something like this and many more, but i always received errors..Imports System.Collections.Generic
[code]...
I want to read a number of items from a file and then associate each of those items with a new button at run-time, so that when the user clicks one of the buttons I can display some information about that item.Can I use a LIST to manage these buttons and items? Can I create a new class and have each list item of that class, such as 'btnID', 'btnText', etc... ?
View 2 RepliesI 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 RepliesPublic Class notifierMain
Public Class Contacts
Inherits List(Of row)
Public Sub New()
[code]....
When I debug this winforms application I get curType = "notifier.notifierMain+Contacts+row" I want to the Validate function to know it is in MyContacts. How do I do this?
I wish to make a project where a teacher views a list box with a list of students of a class. When he selects a name from the first list box the second listbox would change its data to show the grades for that one student.
View 10 RepliesI'm getting System.NullReferenceException error when I try to add the employee info to the Employees list.
[Code]...
y have this class
Private Class MyClass
Public Property propertyOne() as String
Public Property propertyTwo() as String
[code].....
I'm looking for a tutorial on how to Adding a list(of Class) or Collection as another Class's Property.What I am after is something like the Columns Collection for the DatagridView control.I would like to add Items in the graphics screen. Where the item list is displayed in the left panel and the selected Item properties are displayed in the right panel.
View 4 RepliesI am trying to understand classes in VB 2010. I am a bit confused with displaying information from a list into a listbox.When I run the following code, the word collection appears in my list box. How do I drill down into 'hostnames' to display the info I want.
Public Class computer
Private _HostName As String
Public Property HostName As String
[CODE]...
I'm designing a small GUI Windows program that allow staff at a cinema to reserve seats for customers. There will be a total of 60 seats in the cinema. I have two classes in my program:-
1.) MainForm.vb - used for I/O actions and user interaction
2.) SeatManager.vb - used to hold and handle the background methods and functions that make the program work Here is the code for my MainForm.vb class thusfar:-
[Code]...
I seem to have problem with passing a collection/sorted list/ list of strings from one class to another.I am using property procedure to pass it, however nothing is sent to another class. There isn't any error messages either.[code]
View 3 RepliesI'm trying to code a class of RandomNumber. One of the class methods needs to populate a "List (Of RandomNumber)" ... which was passed as a parameter to the method ... with 10 random numbers between 1 and 50. DEAD SIMPLE :)
View 6 RepliesI wrote this - very simple - function, and then wondered does VB have some pre-built functionality to do this, but couldn't find anything specific.
[Code]....
I am writing a WPF application in VB 2008, and need to establish a connection to another system to get pertinent information and if not exit gracefully without displaying the form. I thought I would be able to do this in the Application classwithin Application_Startup and set some custom properties. However, it doesn't appear I can expose these properties outside the Application class without re-instantiation it, which is bad thing. Even variables set up as Friend don't appear to work either.
View 2 Repliesi have an application which i want the user to have access to forms base on their access right. I have a public module that that take care of the uers access right, but when I call this module from the form load event which return true(user has access to the form) then form load continue OR false(user dont hav access to the form) exit sub to discontue form load. but this is not stoping the form from loading.
'Check for user's permission
pubFormID = 107
'Call procedure
[Code].....
I am working with a third-party COM component (i.e. do not have its code). The method in question has the following outline:
HRESULT GetTableInfo(
[in] BSTR bstrTableName,
[in,out] SAFEARRAY(BSTR) bstrColumnTitles,
[in,out] SAFEARRAY(long) lColumnPos );
I have tried to pass a ref to a fixed-size array ((Array)string[6]) and to a List.ToArray(), but it keeps crashing on me. E.g.
Array arr1 = (Array) new string[500];
Array arr2 = (Array) new int[500];
table.GetTableInfo(filename, ref arr1, ref arr2);
To be more specific: I already tried any value for the size (the correct one should be 44). Tried the same for the capacity of a List<>, but that didn't help either. I also tried different types, but it does not accept any other than int.
I don't know why it keeps crashing on me with a general error of that COM component (basically indicating that something is wrong, yet not saying what exactly), since I can confirm that the following VB code works:
Dim TitleList() As String
Dim PositionList() As Long
Call objTable.GetTableInfo(txTableFile.Text, TitleList, PositionList)
Here are the facts: Consider the following program. Sub Main()
[Code]....
Compiling the program in Visual Basic Express produces no errors. However, if the program is imported into the Excel Developer environment; I get the following error: Expected: end of statement with the equal sign highlighted. A side comment: About eight years ago, I wrote a Visual Basic simulation program to study financial trends. I found that version of Visual Basic user frendly! I find the 2010 version very difficult for doing simular projects.
I use the splash screen of the vb.net found on windows form.Is there a way that i could put an initializing while my splash screen is running?like other programs do instead of progress bar.
View 16 RepliesI'm using a structure to hold three arrays:
structure myStruct
dim arrayOne() as char
dim arrayTwo() as char
dim arrayThree() as char
end structure
But how do I go about setting them a value, I've got my instance of myStruct
dim aStruct as new myStruct()
If I try redim, it just tells me it can't change the dimensions of an array, so how do I got about initializing the arrays with values?
I have a form which i want to prevent from loading during the form initializition. which of the form event handles form initialization in VB.NET.
View 8 RepliesI have a winforms app that checks user credentials as it starts.If autharization fails I want to close the app.So I have been using the following
Public Sub New()
_CurrentUser.GetuserDetails
If _CurrentUser.IsAuthorized then
[code].....
I'm trying to return an array of strings from a function, and got surprised by an error.
I would have expected this to work, but it produces an error:
Public Function TestError() As String()
Return {"foo", "bar"}
End Function
[Code]....
I guess I'm unclear on the meaning of the {}'s - is there a way to implicitly return a string array without explicitly creating & initializing it?
Recently installed Visual Basic Express 2008. Install went fine. If I try to open the toolbox (from any of several locations), a meesage "Toolbox Initializing..." appears in the status bar, then after 15-20 seconds, VBExpress simply closes.
View 2 RepliesI tried to initialize a textbox value by using the .Text property
Textbox.Text = 0
But Im getting the error Option Strict On disallows implicit conversions from 'Integer' to 'String'.