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 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.
[Code]...
I have the following object:
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)
The best result I could get was:
Lookup(of MasterCategory, Dictionary(of Date, Integer))
From:
countDictionary.ToLookup(Function(o) o.Key.MasterCategory, Function(o) o.Value)
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
[code]....
It is possible to output all the dictionary values to a textbox? Not the keys, just the values of all the keys.
View 5 RepliesIs 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 this dictoinary:
Dim chardict As Dictionary(Of Char, Integer) = Nothing
chardict.Add("A", 0)
chardict.Add("B", 1)
I wanted to do the following if statement but I am a bit stuck on the syntax:
if chardict.containskey("A")
'display the value that corrosponds to the letter "A"
'in this case display the character 0
[some code]
end if
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 type:
Dim parentDictionary As Dictionary(int,Dictionary(string,string)).
Dim childDictionary As Dictionary(string,string).
parentDictionary.Add(1,childDictionary)
Now I need to iterate over childDictionary to fetch key value pairs.My childDictionary is inside parentDictionary.
is there a way i can have a dictionary or something of that sort that can hold 3 values to 1 key?
View 12 RepliesI 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:
[code].....
I add objects (structure type) to a dictionary with string keys.
i don't figure out how to update a value of a object.
i use TryGetValue to get a reference to a object of the dictionary collection.
But the changes i made at the referenced object are not made at the object at the dictionary.
Any hints how to get a object reference to change values without to re-add the complete object?[code]...
If I had multiple entries under my value in my dictionary, is there anyway I can put each value in separate tags to create an xml document?
Is there anyway to split the 3 values into their own tags?
I still can't assign the process the username of the session id that is associated with it.[code]...
View 1 RepliesI 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 have created a class with a function in it. I have a collection of data I want to pass back. I tried an arraylist first. Now I am trying to use a dictionary. My problem is that it creates the dictionary ok, but I am only get the last row of data from my
Function GetWeldAuditInfo(ByVal ResourceId
As
String,
ByVal VendorId
[CODE].........................
I have a class:
Form
Public Class Form1
Dim teamlist(2) As team
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
teamlist(0) = New team(1, "one", "First")
[Code] .....
Error I'm getting is too many arguments.
I am having some real issues with this one. I have a class which contains two other objects...but I cannot seem to instantiate those sub objects. Here is the code for my class:
Option Explicit On
Public Class Boot
'A collection of Heads and Shells
[Code]....
Notice the count for my two objects, Ohead, and oShell, is zero. Im not sure why this doesnt instantiate properly, as I believe is what is going on.
I can't find what's going on with the following nHibernate HQL.
here's my VB.Net code:
Return _Session.GetNamedQuery("PersonAnthroSummary").SetInt32(0, 2).UniqueResult()
My Named Query:
[code].....
I just like to know if how can i do single form instantiation upon loading my Form..upon loading my MainForm it automatically detect if that MainForm is still exist..ive try putting my code in the contructor of my MainForm..i check through the process in the task manager if that MainForm is still exist..but i think this is not the good idea bcoz..the MainForm takes several seconds to appear..and i think this is bcoz i loop through the process.
View 1 RepliesI have several similar classes but only want to instantiate one of these classes dependant on a selection from my main form.
View 4 RepliesIn C#, you can do this:
new MyClass().MyMethod();
The method is executed and the reference is (typically) discarded since no reference to the object is kept.Is this possible with VB.NET (.NET v4)?
Edit: I suppose this is a better example:
new Thread((x) => doSomething()).Start();
What I want to do is pass a Type to another object's constructor, where the other object creates a new instance of Type. I can create a constructor with a parameter declared as System.Type without problem, but when I try to instantiate it tells me there is no such type.
Public Sub New(targettype As System.Type)
Dim Test As System.Windows.Forms.Form = New targettype
End Sub
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 use VS2005 and I have just started working with the dictionary in particular the Dictionary.ContainsKey method. At the bottom of the page in the msdn library it says the following in the community content How to make sure that Contains functions properly.
View 3 RepliesI don't know if this has been asked before, but we're having a discussion about it today at my job. Should private variables (that are shared/static) be instantiated when they are dimensioned/defined, or is it a better practice to do this inside of a constructor?
Public Class IpCam
Private Const HOST As String = "http://test.com/url/example"
Private Shared _Example As New OurClass(HOST)which one to use?
[code].....
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created table using microsoft sql database fileinto
how to insert values into datagrid
View 9 RepliesHow do I place values of variables to the columns of a listview. There's a guide here Here but it shows how to fill in values from a file.
View 10 Repliesi have constant declared in form1.
View 5 RepliesNew to using SQL and I am having trouble accomplishing something that I figured would be simple.I am trying to create and INSERT that will insert the MAX() value from the first column in one table to the first column in another table while the rest of the columns will be filled with parameters.
I have tried switching my code around to see if I just had the syntax wrong but I've had no luck and I'm not even sure what I'm trying to do is possible (at least in a single INSERT).Here is what I have at the moment:
INSERT INTO [Table2] VALUES(SELECT(Number FROM [Table1] WHERE Max(Number)), @p1, @p2, @p3, @p4, @p5, @p6, @p7, @p8, @p9, @p10)