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]...
I still can't assign the process the username of the session id that is associated with it.[code]...
View 1 RepliesI 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]....
I am trying to populate a dictionary with objects created from data in a recordset, but am having difficulty with VB's object referencing. I am very new to VB. Pseudo code of what I am trying to do:
dim dict as Dictionary
rs = getRecordSet
while rs.moveNext
set myObj = new MyClass
myObj.properties = rs.relevantFields
dict.add myObj.getUniqueKey, myObj
wend
However, all 'objects' in the dictionary are actually references to the most recently created (and thus last) object in the dictionary. I know why what I am doing above is not working, but I don't know the correct way to do it so that each element in the dictionary is it's own object.
I need to Store Objects with Key like:
Key: <Fontname & FontSize> / Object: <Font Object>
Example content:
ArialRegular8 | <Corresponding Font Object>
ImpactItalic10 | <Corresponding Font Object>
TimesRomanRegular12 | <Corresponding Font Object>
These font types come from an external library, the real type is DocumentFont, I prefer not to store just values and recreate the font object later, so I need to store the object, and i want to be able to call Contains() later without looping. like for example Dictionary (of T Key, T Value), is this the best option? Also, to be able to call Contains(), i will have to overload function Contains() using an Interface or this is already built-in in some Collections / Dictionaries when using a String as Key?
I have a program like this.
Module Module1
Public Class Mstr
Public Property Prop1 As String
Public Property Prop2 As String[code]....
But it is not working as I expect it to. You can see it from.The DtlsB properties of all three DtlsA objects are having values from last iteration.
I'm having trouble implementing an IComparer method. Essentially, I want to compare the properties of two custom objects (the properties are of type integer).dE is a Dictionary(Of String, customObj)prTabIndex is a property of customObj and is of type Integer (these hold true for all examples)After some more searching I found this thread which suggested 3 things: a List approach, utilizing LINQ, and using some C# 3.0 features. I've tried three different ways:...rolling my own IComparer implementation:
Public m As Sub(ByRef d As Dictionary(of String, customObj))
Dim sortedD As New SortedDictionary(Of String, customObj)(d, myCompare)
End Sub
[code]....
Note that VS2008 has underlined 'dE.ToDictionary...' (to the end of the line) and giving me two messages depending on where I hover my mouse:
1) "Data type(s) of the type parameter(s) in extension method 'signature' As 'signature defined in 'System.Linq.Enumerable cannot be inferred from these arguments. Specifying the data types explicitly might correct this error. Seen while hovering over "ToDictionary".
2) Nested function does not have the same signature as delegate 'signature'. Seen while hovering over anything after "ToDictionary".
Q1) How far off am I in each of the implementations?
Q2) Which one is the computationally least expensive? Why?
Q3) Which one is the computationally most expensive? Why?
I don't know if this is doable, maybe with Linq, but I have a List(Of MyType):
Public Class MyType
Property key As Char
Property description As String
End Class
And I want to create a Dictionary(Of Char, MyType) using the key field as the dictionary keys and the values in the List as the dictionary values, with something like:
New Dictionary(Of Char, MyType)(??)
Even if this is doable, internally it will loop through all the List items, I guess?
It is possible to output all the dictionary values to a textbox? Not the keys, just the values of all the keys.
View 5 RepliesI 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 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 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].....
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 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 am using vb.net with access database. I am using sql. How can i update database with the value 40'6"(Feet and inches values)
View 5 Replies1- How to add ?
2- The best in i/o file or in sql database.
3- how to add & update & delete.
I have two nested objects, and the form has two ListBoxes, where I want the last to respond to the selection of the former. It can even be some times deeper than 2 levels, which can make it a bit cumbersome. I solve it by raising events in any method that makes an add/delete/rename of these objects, and the form listens for these events, and when fired, clears it's lists, and loops through these objects to populate the lists again. binding lists, but this seems to introduce a few issues. First I need to keep a set of extra lists in the main BLL class, but more importantly, I feel I'm violating the layered structure between the BLL and the form, as in this case, the BLL needs to keep track of the current selected indexes of the listboxes in some variable. So that doesn't feel right, as it makes the BLL vulnerable to what the form does, and I assume is simply principally incorrect.
Following is example of object structure, where two ListBoxes should display "Company Names" and "Employee Names", and the Employee name listbox obviously change according to the selection in the Company Name listbox.
Public Class Form1
private _main as New Main
...
End Class
[code]....
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 am having a problem with objects and arrays of objects. Basically obj_stored holds how many objects I have stored in my text file, in this case t shirts. line(y) is an array that holds each line that has been read from the text file. I then use this to assign values to my array objects properties. For example I know the first line is the color of the first t shirt, second size, third price etc. Then I know the next line will be the color of a new t shirt. There are 6 t shirts in the file.
Dim t_shirt(5) As Clothing.t_shirt
Dim t_shirt_purchased As New Clothing.t_shirt
For x = 0 To obj_stored
t_shirt(x) = Clothing
t_shirt(x).color = line(y)
y = y + 1
t_shirt(x).size = line(y)
y = y + 1
t_shirt(x).price = line(y)
y = y + 1
Next
MsgBox (t_shirt(4).size)
My problem is it seems to be resetting these values after it has finished. Im creating the object each time and assigning values to it's properties but when it's finished it all resets and says 'Object reference not set to an instance of an object'. I'm new to OOP and was wondering what sort of approach i would take to doing this, if the one i am taking is wrong.
So I am aiming to:
Read everything in from the text file.
Create new instances of the objects depending on how many t shirts are stored, (5 t shirts = 5 objects)
Assign the values to my objects properties.
I'm new in this forum. I am also quite a rookie programming in VB2008. In fact I'm not even a professional programmer. The situation is as follows.
I was hired by a company to do an Industrial Engineering job, but after some time, I realized that my job was also to design a database manager in VB2008 for the train wheel stock. So I am terribly lost. My problem here is that I dont know how to compare values and assign the biggest with the biggest, the smallest with the smallest etc. So I want to create a table and auto-arrange the values. An example of what I want to do in a macro of Excel is[code]...
I have used XML serialization to persist objects in my application but I am now interested in using null- able Data types for properties. Will I still be able to serialize?
View 6 RepliesI am trying to change values in all the objects on my form.
First off I call my function when the form loads
SetFonts(me)
Public Sub SetFonts(ByRef Frm As Form)
For Each Ctr As Object In Frm.Controls
[Code].....
I'm completely new to VB.NET and this is likely a few steps over my head, but have managed to get myself this far with just Google.I'm reading an XML file and creating an arraylist of classes for the values in there, as seen:
Public Class yresults
'Dim xdate As XmlNodeList = xDoc.GetElementsByTagName("Date")
'Dim link As XmlNodeList = xDoc.GetElementsByTagName("Link")
[code].....
I have class [code]...
But i get error in For Loop: Object reference not set to an instance of an object at the first line of for loop.
Im doing the same thing as him but in vb express 2008 what i have is a checklist box of 10 toppings, all of which can be selected, (no max or min) to put on a pizza, and i have 3 radio buttons grouped together for pizza size (S, M, L) i cant figure out how to give them vaules in which(for sake of demonstration) s=$5 m=$7 l=$9 and each topping is $0.25 then make them add up to an order total in a msg box or something like that
View 2 RepliesI coded a class that scans an object and maps data from a data table into each one of the corresponding properties, it works very well, however I am not able to set the property of one of the child (coplex objects)
Public Class CntrConfHdr
Private m_CntrConfHdrID As Double
Private m_HeaderCode As String
[Code]...
I want to set the value for the child object TypeCurrency.TypeCurrencyID thus I set the value of the variable sTargetPropertyName to TypeCurrency.TypeCurrencyID but the application willnot work stating that the property can not be found.