How To Create Collection Class And Add List Of Items
Oct 13, 2009How to create collection class and add list of items to collection class that stores list of items?
View 3 RepliesHow to create collection class and add list of items to collection class that stores list of items?
View 3 RepliesI'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 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 can't seem to find any answers that work. Here's the setup:
Info class: Public Class ProductStageInfo
[Code]...
maybe I just don't understand the whole collection/index/thing. All the examples I've found are regarding single dimension collections - 'how to find name within this collection', and the responses use strings to search through them, but somehow the Info class is being treated differently, and I'm not sure how to translate this..
I 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?
I have class called GroupSelect and made a collection List(Of GroupSelect)().[code]...
View 1 RepliesI'm trying to create a collection of variable binding in a class.It is intended to look something like this:
Dim x as integer, s as string
Dim c as new VBindClass
x = 1
s = "Hello"
[code]....
Is there some function that allow us to retrieve a unique ID for a given variable and also get/set based on variable?
Update:At last, I've managed to found the answer. Here's the code:
Dim gh As Runtime.InteropServices.GCHandle = Runtime.InteropServices.GCHandle.Alloc(obj)
Return Runtime.InteropServices.GCHandle.ToIntPtr(gh).ToInt64
I want to create some type of list or collection. Each item on this list or collection will need contain A string name and a integer value. Something like
[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've searched on the Internet and I can't find a solution to this simple problem. I've also looked on Microsoft's MUCH improved MSDN site and haven't found a solution, so here it goes. I'm trying to remove an entry from a list of class and it doesn't get removed. Here's a sample of the code I'm trying: (I renamed the class and variable names to make it a simple example)
Dim lstClass As New List(Of TheClass)
Dim mClass As TheClass
I tried this first
mClass.filename = "The Entry to Delete"
lstClass.Remove(mClass)
[Code]...
currently in my application I have a Global Collection that is a Collection of Collections.Currently I am trying to add items/ elements to one of the child collections of the Global Collection but I am unable to use the collections methods of the child.When I assign a variable to the child collection and return the collection it is just an object with the collection inside.
Ex:
Dim GlobalCollection as New Collection
Dim ChildCollection1 as New Collection
Dim tempCurrentCollection[code]......
I have the following classes:
Product, Service and OrderItem
Product and Service must inherit OrderItem. So basically I want to store OrderItem object in my shopping cart and these object are store in a list.
Public MustInherit Class OrderItem
Private m_enuItemType As TypeOfItem = TypeOfItem.None
Private m_strUserID As Integer[code].....
I'm supposed to create a linked list and add/remove items with a push/pop. Currently I can only push 2 items and pop one before it stops, and I'm not sure what I need to do to fix that.
[Code]...
how to create a panel full of items (textboxes, buttons, labels, ...) and save it as a class with all it's properties so I can create it and place as object on other panel. My goal is to create an application with menu on the side and change workspace (the part on the rest of the form) between 3 or more possible different "workspaces" (made by the classes).
View 5 RepliesHow can I create a list (of my custom structure) to hold only unique items? This list should be created from another list.[code]...
View 5 RepliesI want to create a class that has a list of possible values that can be used.Example: when you create one like this: Dim a As ClassName = , a list will pop up in intellisense.or when the class is used as a property on a usercontrol, you can click the combobox and pick from the values.Here is what the value list looks like for the Color class: vs value selection.PNG
View 4 RepliesI have the following Structure within a class[code]...
How do I efficiently use this list?[code]...
Is it possible to create a user control with a list of custom class type property? If it is, how can I? The issue is that, in designer mode the property is not displayed in property window. I can add the list on markup but when i switch to the designer mode it gives an error which is 'The user control does not have a public property named BookList'.
View 1 Replies[code]The reason that this is a problem is that this is a collection of EventBase objects, but I'm trying to populate it with child classes instead. For example, I might have a JumpEvent class that inherits EventBase, and this is being put into the EventBaseCollection. That means that value.GetType() returns the type of JumpEvent, which as you might guess does not equal the type of EventBase.The goal of course is to simply loop through all of the various events without having to know anything about the sub-classes. Is there a way to determine the type of the base class so that the OnValidate call will work? Or is this just the wrong way to go about it altogether?
View 2 RepliesI am not too sure about the syntax , since I am still very new to VB..
So this is what I have in a class
Code:Public Class DocumentDelivery Implements IDisposable Public Shared RenderList As New List(Of Byte()())
Public Function Initialize(ByRef env As et.User.SystemCommon.Environment, ByRef errs As et.Exec.Utilities.ErrorCollection) As Boolean
[Code]...
I didn't write the existing class, I am just making changes to it. I am not sure why there is no constructor. However, Intialize() is called every time a the class is created.Right now, I set the default capacity of the RenderList, (the class variable) to 1 in Initialize method.
Is there a way to set the capacity outside of the initialize method? what is the syntax?
Aren't arrays of object enumerable?Look for the comments in the code
Public Class AddressCollection
Inherits System.Collections.ObjectModel.Collection(Of AddressType)
Public Sub New()
End Sub
[Code]...
I have a simple subroutine that loads a list from a database. I would like to be able to use the same code to load a ListBox and a ComboBox by defining the list type as the common abstract base class ListControl, and see no reason why I can't - except that VB.NET doesn't expose/implement/whatever the Items collection in ListControl. I note with frustration that this is not the case in ASP.NET. At moment my code is ugly because I have to check what type of list control I have passed in, in order to cast it to a type that has an Items collection. (My code may be ugly for numerous other reasons too, but it is beautiful to me). Is there a way to rewrite the code to avoid having to go through the testing and casting nonsense? (I've stripped it down somewhat so that all that remains is where the problem lies).
Sub loadList(ByVal db As SqlDatabase, ByVal strCommandText As String, lstHost As ListControl, Optional bClearList As Boolean = True, Optional bIsListBox As Boolean = True)
If bClearList Then
[code]....
i am trying to sort the items in a collection(of T), by the start date. but i do not know how to do it. i do know that we have to implement list properties.
View 2 RepliesI have a class that represents some business object, such as this:
Public Class MyObject
Inherits SomeBaseObject ' Implements INotifyPropertyChanged and IDataErrorInfo
Private mMyVariable as Integer
Public Property MyVariable as Integer
[code]....
SomeBaseObject implements both INotifyPropertyChanged and IDataErrorInfo, such that a Validate method will populate the appropriate IDataErrorInfo fields when setting the property values.I also have a collection that supports change events, which I eventually bind to a WPF DataGrid.
Public Class MyCollection
Inherits ObservableCollection(Of MyObject)
End Class
Part 1: Let's say that I have a business rule which says that no two items in my collection may have the same value for MyVariable. How do I set up my events (or implement additional interfaces somewhere) to perform this cross-item validation whenever the property value changes on any item in the collection?
Part 2: Suppose I have a list of integers such that whenever I add a new MyObject item to an instance of MyCollection or change the MyVariable property on any item already in the collection, the value of the MyVariable property must exist in this list of integers?
I often have a class defined and I also define another class that is simply a collection of the other class. To do this I found it easiest just to define the other class as Inherits List(Of Type). The reason I define a collection class is to add extra functionality to the collection. Take the following code for example.
Class Car
Property Name As String
Property Year As Short
[Code]....
how can I define my own collection so that I can reference it by index or name like that. Right now I can only reference it by index.
removal of items in a collection or list using the " For Each " statement to iterate through.This code works:
For Each item As ListViewItem In ListView1.SelectedItems
ListView1.Items.Remove(item)
Next
This code does not:
For Each itemChecked As Object In CheckedListBox1.CheckedItems
CheckedListBox1.Items.Remove(itemChecked)
Next
I have been reading on this for hours today to find out why the first code block works, but the second does not.What I've learned is the "For Each" statement implements the IEnumerable interface. I have seen these terms used many times and scratched my head when it didn't make scense, then just moved along, something to strain my brain about later.Today was later...So since the IEnumerable interface is used, the .GetEnumerator method of the IEnumerable interface is called upon at the beginning of the "For Each" block, this evaluates the collection or list as in: For Each item As ListViewItem In myCollection This is done at the beginning of the iteration through the myCollection, so if the myCollection is altered as in:
For Each itemChecked As Object In myCollection
CheckedListBox1.Items.Remove(itemChecked)
Next
The altering of the list returns the error:List that this enumerator is bound to has been modified. An enumerator can only be used if the list does not change.
[code].....
I am trying to add the file information of the contents of a folder to a collection. Although I am getting the collection to hold the correct number of items that the folder contains, all of the collection's items are the details of the last file in the folder.
I'm trying to use a loop to go through each item contained in the folder and then adding the item details to a collection with the following line
nCounter += 1
collFileDetails.Add(NameOfItem, nCounter)
Next NameOfItem
CAUTION: Noob using Win32 API ahead
I want to display a list of open windows on my computer in a rich text box. So, I'm trying to store the names of all windows in myString, and then set RichTextBox1.Text = myString.
Here's the code
Imports System
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
[Code].....
I am trying to work out a way to group a collection of items like an enum so that I can access them through code else where in my program. i.e I have list of items and sub items
[Code]...
I am trying to work out a way to group a collection of items like an enum so that I can access them through code else where in my program.
i.e I have list of items and sub items
CODE:
I would then like to be able to access then like: G1Level1.Leve2.Leve3
Would anyone be able to advise if this is possible or achievable.