In Objective-C, I could create an NSMutableDictionary which could hold any types of values.
Here with VB.NET, I managed to make a Dictionary, but when I initialized an instance of it, I am asked for a specific value type. How can I enable any value types within one single dictionary?
I need to compare two dictionary values if the types stored are equal, this is what i have
if gettype(Args(key)) = gettype(argtypes(key)) then
'' do something
end if
[Code]....
I wrote the following function to randomize a dictionary object:
Friend Function RandomizeDictionary(Of T)(ByVal oCollection As Dictionary(Of String, T)) As Dictionary(Of String, T)
Try
Dim oResult As Dictionary(Of String, T) = Nothing
[code]....
This code works fine on simple dictionary objects, but when I use it with complex types I get a type cast exception. For example, I have an object X that Inherits Dictionary (Of String, Class Y). If I call the randomize function on object X, I get the type cast exception. I don't really understand why it cares what the type of the dictionary value is, I thought that was the point of using generics.
In summary the following all work:
Dim x as New Dictionary (Of String, String)
Dim x as New Dictionary (Of String, Boolean)
Dim x as New Dictionary (Of String, Integer)
This does not:
Dim x as New Class X
Class X Inherits Dictionary (Of String, Class Y)
I can't seem to get a single form that is held in a dictionary(of integer, <Form>) to create instances passed 229 times.
For instance i can only open 229 instances of the same form. I open and close the form. So technically i open 229 forms and close 228. Any forms opened afterwards give a win32 exception. I clear the the dictionary key upon form close.
I have changed the dictionary declaration to (of long) but get the same issue.
How to enable single gridview cell when we wish to update/modify the data in data base? In VB.Net and im using MS Access as my database.
View 3 RepliesIf you mark your application using "Make Single Instance Application" option in the application settings tab and run your application under a GUEST account or a restricted limited/standard account the application throws UnAuthorizedAccessException or CantStartSingleInstanceException.
Take the following steps to reproduce this behavior.
1) Create Windows Form application.
2) Enable the "Make Single Instance Application" in the project properties.
3) Log onto a GUEST account and open the application twice to simulate StartUpNextInstance.
We need developers to reproduce this behavior and post any valuable input if you experience these symptoms.
When posting information please include the following:
a) The operating system version + service pack.
b) The .NET framework version used.
c) Verify this symptom is present when running under GUEST account.
To workaround this issue turn off the "Make Single Instance Application" option ad create a Local named mutex in the StartUp() event.
[Code]...
In VB.NET I would like to create a complicated data structure with multiple types of data stored in an array like format (see below). I am trying to create a data structure that would look something like this: [Name; xLoc; yLoc; zLoc; [Jagged Array]] Note: Name needs to be dimensioned as a string, xLoc and so forth as integers. The Jagged Array would look like this:
[Code]...
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 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 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 want to allow the user to enable or disable a textbox by clicking either a button (enable) or the reverse. (disable) if the user clicks the enable button the textbox should receive the focus.
View 4 RepliesI 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 have a class with a Property called 'Value' which is of type Object.Value can be of any type, a structure, a class, an array, IList etc.My problem is with the setter and determining whether the value has changed or not.This is simple enough for value types, but reference types and lists present a problem.For a class, would you assume that the Equals method has been implemented correctly, or just assume that the value has changed every time the setter is called?If I did assume it's changed, then perhaps I should assume it for value types as well, so that the behaviour is consistent.
View 2 RepliesSay I have a code with 3 methods that do some pretty intensive work. Would executing these methods on 3 seperate threads be faster then executing them one after the other on a single core cpu? And what if it's a dual core or HT?
View 8 RepliesI am trying to make a list, separated by a comma, of entries from a single column in a SQL database. I have been spending the last several days searching for a way to do this, but every thing I found either didn't work, or wasn't exactly what I was looking for.
The query will pull all the email address that are not null. What I need to know is how to take the result of that query and make it look like this:
email0@address.com, email1@address.com, email2@address.com, etc, etc, ...
I feel like I should know this, but for the life of me, I can't remember nor can I find it in any of the textbooks I have.
I am using Visual Basic 2010 and SQL Server 2005. I also have access to Visual Basic 2005 if needed.
I use SqlParameters when executing database statements. I know that I can replace a single quote with two single quotes... but in the past SqlParameters took care of this for me. I have two projects.. in one, the SqlParameter does this and it handles single quotes fine, in another, it does not and I'm at a loss why (I even copied and pasted the code):
[Code]...
I am trying to use the DGV to view various properties from a variety of different class instances. Is it possible to bind each cell individually?
View 9 RepliesI am trying to update a row or a single cell in ms access through vb.net. But when i update the text box named NRIC, say for example i want to update "s4522147B" to "tr4521856C" and mean while leaving the other fields the same.
But the thing is when i make the changes in nric.text (textbox), the dataset actually updates the whole column in the table instead of the selected textbox.
Below is my code for the update part
[Code].....
How would I go about copying every value of one Dictionary list to another Dictionary list.
Here is what I've done:
VB.net
' Assign values to player pairs enumeration
Private Enum cmptrPairsList
empty = 0
[code]....
I have a few problems i need to solve. Firstly, I am looking for a piece of code i can use to display a picture from a bank of pictures. It will work on the basis of generating a random number and loading a picture that corresponds to that number.
i.e. Dim RandNumber As Integer
Dim RandClass As New Random
RandNumber = RandClass.next(1, 10)
If RandNumber = 1 Then
Picturebox1.image = picture1
[Code]...
Secondly, can I then use subsequent picture boxes to display pictures from the same bank of images, without displaying the same image? Finally, I then need to be able to click the picture or a button beneath the picture to select it as an answer to a question and then the whole process starts again.
I have written this function to auto correct gender to M or F from different values in a string array. It works fine but my manager told me to use Dictionary which he said is more efficient.[code]
View 2 RepliesIs it possible to change the key of a dictionary?
View 6 RepliesI have a dictionary in the form of: { "honda" : 4, "toyota": 7, "ford" : 3, "chevy": 10 }
I want to sort it by the second column aka (the value) descending.
Desired output:
"chevy", 10
"toyota", 7
"honda", 4
"ford", 3
Is it possible to change the key of a dictionary?
View 11 RepliesI need to order a Dictionary in VB.net based off of the keys. The keys and values are all strings. The dictionary does not have a .Sort(). Is there a way to do this without having to write my own sorting algorithm?
View 3 RepliesI have a dictionary of key=string and value=datatable. I use a key to retrieve a datatable and assign that datatable to a new variable. Then I make some updates to the variable. However, I find that the dictionary itself is being updated even though I'm only updating the variable. This causes significant issues when I try to reference the dictionary later. How can I set up my dictionary so that it won't update when I use a value?
dim dt1 as datatable
dt1=dictionary(key)
For row=0 to dt1.rows.count
dt1.Rows(row)(4)=dt1.rows(row)(4)/2
Next row
'at this point, when I look up dictionary(key), the value I get shows all of the original values divided by 2.
It is possible to output all the dictionary values to a textbox? Not the keys, just the values of all the keys.
View 5 RepliesHow to make a dictionary? that left side have listbox, rightside have one picturebox and textbox. When i clicked on the "APPLE" in listbox, it open APPLE'S picture and describe, when i clicked on the "ORANGE" in listbox, it open ORANGE's picture and describe.But now the problem is, i want to make it all in a exe, so that APPLE & ORANGE's picture and describe will be combine into the EXE, so what is the most easiest code to done...
- LOAD THE PIC INSIDE THE EXE (RESOURCE?)
- LOAD THE TEXT INSIDE THE EXE (RESOURCE?)
- SEARCH THE LISTBOX FOR SPECIFY ITEM
EDIT: With search function...
[code] For example, if the word was "cat" it would return true. If the word was "jlakfh", then it word return false. To do this i need some kind of dictionary array or something. How do I do this? If it helps, I only needs words with less than 7 letters in them, and more than 2 letters in them. Also, I don't need the definitions of the words. I only need the words themselves in the arary. Do I need to manually input all the words into an array or is there already a dictionary control or something that I could use?
View 3 Replies