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
[code].....
I have created a Dictionary class (MyDictionary for the example). I am currently trying to pass MyDictionary into a function, filter it into a new instance of MyDictionary and pass this new instance into another method. When I am attempting to create the second instance from the filtered first instance of MyDictionary via Lambda Expressions and the ToDictionary Method, I am getting the following error:
Unable to cast object of type 'System.Collections.Generic.Dictionary`2[System.Int32,System.String]' to type 'MyDictionary'. I have simplified the example and recreated it in LINQPad and am getting the same error.
Here's the simplified version of my code:
[Code]...
I have a generic class called SessionManager to control the types of variables I store in session. I have been doing it for String, Integer, List(Of T) without any issues like this.
Public NotInheritable Class SessionManager
'''<remarks>
'''Private constructor to prevent instantiation of, or inheritance from, this class.
[code].....
I would like to do the same for Dictionary(Of T, T). I would like 2 generic private methods for Dictionary(Of T, T) for getting and setting; GetFromSessionAsDictionary and SetInSessionAsDictionary. (When nothing returns empty dictionary like the List(Of T) properties and sets in session) And this should allow me to create as many public properties of Type Dictionary (e.g. Dictionary(Of String, String), Dictionary(Of String, Integer)) as possible to store in session.
EDIT:This is what I have ended up doing after trying to make it generic Dictionary(Of T, T), and it works without any issues. What I want instead is a solution that would not constraint the type to Dictionary(Of String, Integer).
Private Const _Dictionary1OfStringInt As String = "DICTIONARY_1_OF_STRING_INT"
Public Shared Property DictionaryOf As Dictionary(Of String, Integer)
Get
[code].....
You can do this
Code:
Dim Test() As String = {"Stuff", "Stuff", "Additional Stuff"}
Is there a way to do that with a generic dictionary? Also, is there a name for that?
As I am beginner in LINQ, I have small problems. I have dictionary of Char and Long, and I would like to use LINQ to retrieve Char with highest Long Value. I saw some C# samples, which look pretty easy, but I can't achieve such expression in VB.Here are two expressions, and I don't think they are most efficient possible.
[Code]...
Very easy today, I think. In C#, its:
Dictionary<String, String> dict = new Dictionary<string, string>() { { "", "" } };
But in vb, the following doesn't work.
Public dict As Dictionary(Of String, String) = New Dictionary(Of String, String) (("",""))
I'm pretty sure there's a way to add them at declaration, but I'm not sure how. And yes, I want to add them at declaration, not any other time. :)
I've also tried:
Public dict As Dictionary(Of String, String) = New Dictionary(Of String, String) ({"",""})
And...
Public dict As Dictionary(Of String, String) = New Dictionary(Of String, String) {("","")}
And...
Public dict As Dictionary(Of String, String) = New Dictionary(Of String, String) {{"",""}}
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
[code]....
I have a mutable class that I'm using as a key to a generic dictionary. Two keys should be equal only if their references are equal. From what I've read, in this case, I don't need to override Equals, GetHashCode , or implement IEqualityComparer.
View 5 RepliesI have the following dictionary:
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(...)
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 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.
View 6 RepliesI have a Generic Dictionary contained or nested as a child in another Generic Dictionary. I need to be able to access the child dictionary objects by key. When I attempt to do this I get the following error:
"Value of type 'System.Collections.Generic.KeyValuePair(Of String, String)' cannot be converted to 'System.Collections.Generic.Dictionary(Of String, String)'."
So it seems that the contained Generic Dictionary is being returned as a Generic KeyValuePair when accessed via a key as opposed to iterating through the parent dictionary in a For/Each loop.
The first section of the sample works OK (using a key to access a string value in a dictionary).
The second section of the code works OK (iterating through the dictionary values in a For/Each).
The third section of the sample is where the error occurs (using a key to access a nested generic dictionary...see underlined code).
Dim td1 As Dictionary(Of String, String)
For Each thisKey As String In td1.Keys
Debug.Print(td1(thisKey))
Next
Dim td2 As Dictionary(Of String, Dictionary(Of String, String))
[Code] .....
I'm having problems binding 2 combo boxes to a generic dictionary, this is what i have done so far
Dim cb As ComboBox = sender
Dim name As String = cb.Name.ToString
Dim dict As New Dictionary(Of String, List(Of String))
[Code]....
I was trying to create a generic Dictionary that implements IXmlSerializable (credit to Charles Feduke).
Here is my trial:
Sub Main()
Dim z As New SerializableDictionary(Of String, String)
z.Add("asdf", "asd")
[Code].....
If i wish to put items into a System.Collections.Generic.Dictionary, I can either Add or set the Item.I know if you do Add it helps you check if the key already exists and if not it throws an exception.Now I'm curious, so if I'm adding a ton of items, should I prefer setting Item instead of Add since Add does unnecessary checks that may actually slow things down?
View 3 RepliesI have a case insensitive dictionary in asp.net/vb.net like this:
Dim caseInsensitiveDictionary = New Dictionary(Of String, Single)(StringComparer.OrdinalIgnoreCase)
it holds values like this
[code].....
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 need to sort a list (of person) to person.Age within person.Department. f I user personlist.sort with a comparer for Age and then sort again with a comparer for Department, the sequence of age is destroyed.
View 1 RepliesI 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"
How do I achieve this using a Lambda expression?
I was trying something like this:
[code..]
I can insert values into a VB.NET Dictionary when I create it? I can, but don't want to, do dict.Add(int, "string") for each item.
Basically, I want to do "How to insert values into C# Dictionary on instantiation?" with VB.NET.
var dictionary = new Dictionary<int, string>
{
{0, "string"},
{1, "string2"},
{2, "string3"}
};
I have script like this :
Private Sub cmd_save_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmd_save.Click
If txt_kdbrg.Text <> "" Then
[Code]....
give me alternative script, if object is duplicate script give alert or message "already exist"
i'm using below code to save data to sql but i need to save the new data only not all data
table name :
CHECKINOUT
key :
CHECKTIME
[Code]...
Is there an easier way to prevent a duplicate insert after refresh? The way I do it now is to select everything with the all fields except ID as parameters; if a record exists i don't insert. Is there a way to possible detect refresh?
View 8 RepliesI have a form where two fields on the first page of the form make up the primary key. I want to check for duplicate values before attempting to insert the record, since I don't want the user to go all the way through the form only to find out they can't submit it. So I'm trying to check for duplicate values when the user tries to go to the next page of the form. I wasn't quite sure how to do it, and sure enough I'm getting an error. ("Object reference not set to an instance of an object.") The problem is apparently in my if statement, "If myValue.Length > 0 Then", but I'm not sure what needs to be in place of that.
Protected Sub CustomValidator1_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles CustomValidator1.ServerValidate
'get values
[code].....
I have two table, src_table and dest_table src_table contain multiple rows including duplicates I want to copy rows from src_table to dest_table without duplicates.
View 3 RepliesHow to make only one record at a time get inserted in the database table and also delete from the other table?
Once the details are filled ,I insert it in table1 as the new record and I delete the same record from table2.[code]...
I need to automate the installation of some Antivirus applications. I can easily do it by utilizing the Process Class, but I also needed to know if there was a way to automatically input the serial key.
I thought I remember someone mentioning a property or something that could be used for that, but I can't remember what it was or who said it.
the thing is i'm a .net programmer at varsity but i cant figure out how to program or insert shortcut/icon keys on the web browser application e.g back,refresh,stop,go. i'm only able to do this using command buttoms. so i want to use simple icons like those on some web browsers.
View 1 RepliesLets say i have a class Employee which cotains two propeties (Name, Year) I have another which basically contains list of Employee object i.e EmployeeList.[code]...
View 4 Replies
