1) SortedLIst has a GetKey property: you ask for the nth key in the sorted list of keys and you get it. SortedList(of TKey, TValue) does not have this kind of feature. Why not?
2) SortedList stores values as "object." Is this a less memory-effective method to store values of Double than SortedList(of TKey, TValue)?
I want to create an implementation of the IDictionary(Of TKey, TValue) interface to provide some wrapper functionality.
[code]...
The error is Interface 'System.Collections.Generic.ICollection(Of T) is not implemented by this class. I am not sure what to do about this error. I don't even really understand it. I trade to change the (Of T) to (Of TValue) but that didn't help.
Is it possible to retrieve the index number of an item/key in a Dictionary(Of TKey, TValue) object?
View 13 RepliesIs there any way to do the same in VB.NET?[code]...
View 1 RepliesHow to get the key of a sorted list from the corresponding value directly without using For Each loop. For instance in the following code snippet, I want to get the key value (and not the index) of "Canada", how?
Code Snippet:
SortedList
Imports System
Imports System.Collections
[Code]...
I have the following in VB:
Dim sources = From source In importSources Select New With _
{.Type = source.Key, .Source = source.Value.Name}
dgridSourceFiles.DataSource = sources
[code]....
Here's a list example
SortedList name = test
"nothing" | 0
"something" | 1
How can I go about running a for each loop or something to add each first column in test to, say a listbox.
Listbox should just have listed.
nothing
something
I tried
For Each i In text.Values
lbTest.Items.Add(i)
Next
But that produces:
0
1
I have a the need for key value pair that I wish to sort so I decided to use a SortedList instead of a HashTable.I am adding the data in the order below to my SortedList which is the order I need it in
Key | Value
--------------------------------
1 "700-800" | List(Of Object)
2 "900-1000" | List(Of Object)
[code]....
The key is a string and the value is a List of objects. The key is representing a time slot that has been concatenated from two integer values and delimited by "-". "700" as a string was 0700 initially an integer.e.g.
Dim key As String = slotTimeStart.ToString() & "-" & slotTimeEnd.ToString()
But once these key value pairs are added to the SortedList they appear in the order
3 "1100-1200" | List(Of Object)
4 "1700-1800" | List(Of Object)
[code]....
Unfortunately I recieve the times slots as two integer values which cannot be changed.Is there any way to force a sort on a SortedList? or is this problem because of the way I am storing my key? Is there a better way to store it?
i can get a value, a key out of a list by using index ,key or value parameters but a kvp as object ?nattelip
View 13 Replieswhen you use the object browser to see the features of a sortedlist elementat is not shown , but because a sorted list inherets features of ienumerable it works, cant that be corrected
View 1 Repliesi have a sortedlist variable called :
Cart
which contains two Cartitem object and within these two objects is a further object called Product.i wish to amend the Product object Property named Quantity
["860"] = {Cartitem}
["861"] = {Cartitem}
When i attempt to update the Cartitem object using the key value it overwrites Cartitem to Product.
Present Update
Cart(key.ToString) = product
results in
["860"] = {Product}
How may i update a Product property without replacing Cartitem object to Product?
I'm making a sortedlist I can read a file into my program but do someone now how to show the output? Its made with classes and they will work. How to show the output of the file because I can't find.
This is the Form1
Public Class Form1
Public lijst As New SortedList(Of String, bankrekening)
'Dim spaar As spaarrekening
'Dim zicht As zichtrekening
Private Sub OverschrijvenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OverschrijvenToolStripMenuItem.Click
FrmOverschrijven.show()
[Code] .....
I have a txt file I' m trying to read a line and add it to the array list, I' m identying the begining of the new line with B and N charecters in the 11 and 12 th positions respectively. Now the problem is that few keys are getting dropped the structure of the file is
10000BN test 1 test2
10000S0000 test3 test 4// these are getting dropped because they are on a new line
10000S 0000 test5
so how do I add these two lines to the record
[Code]....
I have a SortedList
Protected _Items As New Generic.SortedList(Of String, _Control)
I am adding items into this SortedList
_Items.Add(_key, _Control)
[code].....
The code below shows me (I think) that the "for each" loop is about 10% faster than the "i to n" loop, but the "for each" loop creates 567k in new memory? Is this right? Which way is generally most efficient with regards to speed and memory usage? If you want to run this code in VB just add a button and 2 labels to a form.
[Code]...
What I need is to be able to put in a SortedList a combination of two fields that are non-unique, but the pair is (like database composite keys).More precisly, i have my list, and i want to be able to do this with it
Dim myList = New Generic.SortedList(Of String, String)
myList.add("aaa","aaa")
myList.add("aaa","bbb")
[code].....
VB2008. I would like to use a Dictionary(Of TKey, Tvalue) where the key is a pair of Integer (and TValue is String, no problem). How can I declare it ? How can I add an item ? How can I retrieve a value, knowing the key ? I can do it when the key is an Integer, but with a pair of Integer I am lost.
View 2 RepliesI created my own Dictionary class, based on the .NET Dictionary. Now I want to overload then Item() Method. This works fine with the following code: Public Overloads Property Item(ByVal key As TKey) As TValue
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I am writing a class library to interact with a domain Active Directory. In my object model, I have the following:
Domain;
Organizational Unit;
Group;
User.
In my Domain object, I have an Entries property and an Add() method.
public class Domain {
// The ReadOnlyDictionary<TKey, TValue> is a custom wrapper over an IDictionary.
public ReadOnlyDictionary<string, IDirectoryEntry> Entries { get; }
public void Add(IDirectoryEntry entry) {
Entries.Add(entry.Name, entry);
[Code] .....
For your information, I implemented the INotifyPropertyChanged interface to ease my life, but I don't seem to find a way to make it work the way I want. Perhaps am I not doing things right somehow, as for the location of different methods, I don't know. How can I make my Domain aware of a change that occured within one of its Entries, so that the TKey value is also changed? That is wanted because one could possibly add an entry, change its name meanwhile adding a new entry with the "old" name of the actual within entry, and cause a conflict, etc. In the end, causing the test to fail. But I'd like to make it pass like it actually is. Is there another better approach or workaround?
There are a lot of different generic collections available, so the wisdom in creating a new one may be questionable right from the start.However, I often find myself wanting the same features from my custom generic lists, but cannot quite find all of those features in an existing object; namely, I would like to have a generic collection which works like a List or Dictionary (much like the System.Collections. ObjectModel. Keyed Collection(Of TKey, TValue)), but also works like a BindingSource does when it is bound to an ADO object (that is, it supports full sorting and filtering as well as currency).A feature I almost never need however, is transactional adds (the BindingSource's ability to 'cancel add-new').Again, with so many existing collections out there, I should take a moment to go over the reasons why none of them quite meet my needs.There is the System. ComponentModel. BindingList(Of T) which would provide some of the functionality of a BindingSource, but has strict requirements about the type {T} implementing IComparable in order to support sorting, and does not provide filtering (it is not an IBindingListView).It also only maintains a base item list by index, so does not provide keyed access.We could use simple databinding with a custom list inheriting from System.Collections. ObjectModel. Keyed Collection(Of TKey, TValue) bound to a BindingSource, but again TValue would have to implement IComparable to support sorting and we would still not have filter support.So to get all the features I was after, I decided that the best thing would be to create a new generic collection object which implemented IList, IDictionary, IBindingList, and IBindingListView (along with a few others) and would be capable of serving as a simple list, or as a binding source while providing full sorting and filtering over any newable object type.
To that end, I've created the KeyedObjectModel which contains the KeyedBindingList(Of TKey, T) generic collection/binding source. This collection can be used as a typical list, or as a binding source (you do not need an additional BindingSource component between the collection and UI controls, although you could certainly have one).Various constructors are provided in order to initialize an instance of the collection as either an enhanced list-dictionary, or as a complete BindingSource.Any object that has a public constructor which takes no arguments can be used at type {T}, providing that the object has a property of type {TKey} which will contain unique values for each entity in a given collection.If the object implements System.ComponentModel.NotifyPropertyChanged then the collection will also bubble up property changes on the current item to the collection's CurrentItemChanged event.An implementation of IComparable on type {T} is irrelevant because sorting and filtering are performed on the property values of {T} based on the type of the specified property.The current design of KeyedBindingList(Of TKey, T) is in an 'alpha' stage.The class is mostly complete from a feature implementation standpoint, however, the code has not yet been optimized and the base collections of values, keys, and view are being maintianed in generic lists of their own, rather than raw arrays.However, even without performance tuning, the collection appears to be performing quite well, up to a few thousand entries, given the amount of flexibility and funcitonality it provides.At this stage, I would really love to get some peers to try using the compiled DLL and beat up the collection a bit.Once the code has been proven and optimized, I will publish it as an example.It is a fairly complex class though (currently made up of eleven or so partial classes) so I don't really want to post the code until it has been optimized. [code]
I want to make a GetAllContacts method which takes a sort parameter of type Func(Of Contact, TKey) which is the same type that the OrderBy method for an IEnumerable(Of Contact) takes.[code]"Too many arguments to extension method 'Public Function ElementAtOrDefault(index As Integer) As Contact' defined in 'System.Linq.Enumerable'." on the second parameter.
View 2 Replies