I have a VB.NET project where I am able to iterate through the keys and values collections of a dictionary object using an index:
MyDictionary.Keys(idx) MyDictionary.Values(idx)
When this code is taken from the test project and placed into the real project I get the following error:
'System.Collections.Generic.Dictionary(Of Double, String).KeyCollection' cannot be indexed because it has no default property.[code]...
In the line in sub search that says "dtf.Keys(idx) = 0" place your cursor after the right parenthesis and backspace you should get a tooltip that says, "<Extension> ElementAtOrDefault(index as Integer) as Double - index: the zero based element of the index to retrieve.
I want to group items from a linq query under a header, so that for each header I have a list of objects that match the header title. I assumed the solution would be to use ToDictionary to convert the objects, but this allows only one object per "group" (or dictionary key). I assumed I could create the dictionary of type (String, List Of()), but I can't figure out how to write it. As an example I have written a simplified version below.
countDictionary As Dictionary(of Category, Dictionary(of Date, Integer))
The Class has a Enumeration Property. For the purposes of demonstration, I'll call it MasterCategory.I have been trying to get out an object that looks like the following:
groupedCountDictionary As Dictionary(of MasterCategory, Dictionary(of Date, Integer)
Which results in a IEnumerable (Of Dictionary(of Date, Integer)) for each MasterCategory value.However, I need that IEnumerable of Dictionary flattened to one dictionary with all the integers summed (total counts) for each date. I then tried to use various selects and group bys (from numerous stackoverflow posts) to "flatten" it, but my efforts have fallen short.
Current Code
[Category Class] - MasterCategory As Enum - Name As String etc
I have a dictionary(of someType, someOtherType) (the types are immaterial). With a given value, I need to find all the keys that have that value in the dictionary. What I am currently doing is this:
Dim foundList as New List(of someType) For each key as someType in myDictionary.Keys If myDictionary(key) = givenValue Then
Dim idQueuedJobs As IDictionary(Of Int32, KeyValuePair(Of String, Int32)) = New Dictionary(Of Int32, KeyValuePair(Of String, Int32))
Why duplicate KeyValue pair? This is because the first Int32 is just a normal index, and the String followed by another Int32 contains systemnames and the priority of the qued job in idQueuedJobs
I want to calculate the total number of systemnames in idQueuedJobs, how can i obtain this count by using the groupby method?
Something like this maybe?
numberOfSystems As Int32 = idQueuedJobs.Values.GroupBy(...)
Dim Rooms As New Dictionary(Of Integer, Of Integer) Rooms(1) = 101, 102, 109, 110 Rooms(2) = 103, 104, 105 Rooms(3) = 106, 107
I want to know if i can obtain how many keys are in the dictionary For example, in this dictionary i have 3 keys, and if i use Rooms.Count it returns me 9 thats each pair of keys-values, but i want to obtain 3, each diferent value as key.
EDIT: Sintax error P.D: I cant use now because i have to use in a webservice filtered by IP, but VS2010 if i use count on the dictionary, tells me that will contain the number of the keys/value pairs.
I have this dictionary.. Dim Rooms As New Dictionary(Of Integer, Of Integer) Rooms(1) = 101, 102, 109, 110 Rooms(2) = 103, 104, 105 Rooms(3) = 106, 107
I want to know if I can obtain how many keys are in the dictionary. For example, in this dictionary i have 3 keys, and if I use Rooms.Count it returns me 9 that's each pair of keys-values, but I want to obtain 3, each different value as key. Syntax error. I cant use now because I have to use in a webservice filtered by IP, but VS2010 if I use count on the dictionary, tells me that will contain the number of the keys/value pairs.
I have a dictionary with the keys being integer and the values being string. I was wondering how can I sort the dictionary in DESCENDING order using its keys.
Is there any reason to favor one of these approaches over the other when inserting into a generic dictionary with the possibility of a key conflict? I'm building an in-memory version of a static collection so in the case of a conflict it doesn't matter whether the old or new value is used.
If Not mySettings.ContainsKey(key) Then mySettings.Add(key, Value) End If
I have a generic dictonary which is templated in the following manner:
[code...]
If I wanted to omit certain list items against arbitrary keys (that is the items that are in the list contained within the value part of each of the key value pairs making up the dictionary) given some arbitrary condition (lets say omitting list items where a list item contained the string "abc")
I would expect to able to create/project into a new dictionary which would contain entries which contained lists WITHOUT those items whose name contained "abc"
I have a dictionary that has strings variables as keys and a List collection of doubles as values.
Dim CellAddressContainer As New Dictionary(Of String, List(Of Double)) Dim Results As New List(Of Double) Within a loop I populate the Results variable as follows:
I'm making a custom scripting engine type thing. I'm trying to add an option to where you can select a list of functions from a dropdown combobox. I want it to display the "Display Names"(Keys as String) of the items in the combobox, but I want it the DisplayNames to point to the (Value as String).[code]so I want "Equals" to be displayed in the combobox, but I want "=" to be the real value.
I have a program which will search the entire registry for a keyword and display all the matching keys/values in a listview. The user can then select the desired keys/values and delete them. Since this a program that deals with registry, I want to give the users a way to backup the registry before they do the delete operation. I would like to know what is the best approach for this.
3 questions here: 1- Should I backup the entire registry ? 2- Should I backup only the keys/values that the user has selected in the listview ? 3 - Can I have the sample code or appropriate URL's which describes this.
I have a problem detecting whether one of the arrow keys is pressed, all the other keys seem to be detected apart from the arrow keys??? I have set key preview to True........ It detects the arrrow keys BUT ONLY if I have NO other controls on the form??? example..
Me.Text = e.keycode
It works, but then if I add a button for example, it stops.
