How can I have it so that you can add items to a System.Collections.Specialized.String Collection but only if it is not there already? I have already found the code, but deleted it and cannot remember it. It is something like[code]....
View 9 Replies[code]...
What's really the point in using the former?It's hard to use linq if I used the former. I have to convert that to an array first which is difficult because there is no (asarray) function.I think I would change all of my code that's using System.
Collections.Specialized.StringCollection to System.Collections.Generic.List(Of String)
Say I have a text file I want to load it to a System.Collections.Specialized.StringCollection
object dim a as System.Collections.Specialized.StringCollection
set a = a contains many systems System.Collections.Specialized.StringCollection object.
Each line in text.txt go to an element in a.
I'm trying to block specific websites by adding them to a system.collections.specialized.stringcollection in my.settings, where i use
Private
Function
GetBrowser() As
[code]....
I wanted to create a custom control with a custom Item-Collection in it.(Similar to the ListView Items, but with other properties)I wrote a Class that holds properties of a single Item data (ClassItemData) and another class that "Inherits System.Collections.ObjectModel.Collection(Of ClassItemData)". The Collection class contains a public event (ItemCollectionChanged) which is raised when "ClearItems", "InsertItem", "RemoveItem" or "SetItem" is called. (I used "Overrides" on all these functions and added the Raise Event to them.) The event is handled in the custom control itself and causes the control to refresh/repaint itself. The collection class contains also "Default Public Overloads ReadOnly Property Item(ByVal index As Int32) As ClassItemData" which returns the Item at the speciefic index.
The control refreshes itself when I place the control on a form and use code like: ControlName.Items.Add("TestItem") Unfortunately the control does not refresh itself when I use: ControlName.Items.Item(0).Visible = False The value of the Item itself has changed after this, but the control does know about the changes and does not refresh itself. If I do a manual repaint/refresh of the control, it looks all fine, but it does not work automatically. Does anyone know, what I have to add, so I can handle an event or something in the control when a property in the ItemData class has changed? How do I recognize changes in existing items and raise an event in the custom event?
I have following instance of System.Collections.Specialized.NameValueCollection:
Dim UserSelection As New System.Collections.Specialized.NameValueCollection
UserSelection.Add("D_Color1", "Black")
UserSelection.Add("D_Color2", "Green")
UserSelection.Add("D_Color3", "Purple")
I need to save this instance to hard disk and then load it back from hard disk as an instance. How do I do that?
I'm having a problem with this code in the highlighted line(*); getting the error in the heading.
Dim htmlarraylist As New List(Of iTextSharp.text.IElement)
htmlarraylist = *HTMLWorker.ParseToList(New StreamReader(tempFile), New StyleSheet())*
[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 Repliesin what situation will an item in System.Collections.Generic.List not be removed successfully?url...The way they phrase it makes me think that it is possible that a Remove operation on an item found in the List(Of T) could actually fail.
View 4 RepliesThis code:
vb Dim s As String = strContents '<a global variable) Dim currentPos As Int64 = 0 Dim endPos As Int64 = strContents.Length - 1 '// A dictionary, used to count the frequencies Dim characterCounter As New Dictionary(Of [String], Int64)() While currentPos <> endPos '//
[CODE]...
Gives this error: Value of type 'System.Collections.Generic.KeyValuePair(Of String, Long)' cannot be converted to 'System.Collections.DictionaryEntry'.
Is there a way to create a collection of collections? e.g. I created a collection ListOf(Lines) After I add all my lines to it, I want to store this colleciton in another listOf(Collections). The reason I want to do this is because i want to create several separate collections of lines and I'll need to loop through them all to look for a certain line and I thought this would be a good approach if it's possible.
[Code]...
I'm implementing a customized Graph algorithm in vb.net, and I'm having the following problem:
Supose the code:
dim col as new collection
dim myC as new system.collections.genericList(of myClass)
dim obj1 as new myClass
dim obj2 as new myClass
[code].....
'In the next statement, the myC2 inside col collection will be decreased to contain 'only obj1, like myC. I supose this is for myC and myC2 contains only a pointer to 'objects obj1 and obj2 as well col contains pointers to myC and myC2 myC.remove(obj2)'The problem is that I have to only copy myC to myC2, like a ByVal argument in a function,'instead a ByRef argument, in order to mantain a copy of objects in myC2 while these 'objects should be removed from myC. How should I do it?
I have a Collection, the keys are strings and the values are Collections. In the sub Collections the keys are strings and values are Singles/Floats. How would I loop through all of the data? I need to get the keys and values not just the values. I've tried this but it produces a cast error:
[Code]...
I am using Visual Studio 2005 and am writing a SSIS package. In the package I have a VB.Script that looks at a directory on a server and creates a list of the files. I then have a store Proc that looks at a table and gets a list of files that matches the files in the first array. The result is a fullresultset. The next step I need to create a 3rd array that only contains the rows from the first that are not in the second. However, I am getting the following error. Error: The script threw an exception: Unable to cast object of type 'System.Object' to type 'System.Collections.ArrayList'.
View 3 RepliesI recently discovered that the standard System.Boolean value is actually 32 bits - this seems pretty "far out there" since it's only ever going to be 1 or 0 - I found this information in somebody's blog which contained 3rd-party documentation on the System.Collections.BitArray. According to this blog, the individual Boolean is 32 bits while the individual index entry in a BitArray is actually just 1 bit - official documentation here at
MSDN indicates that in reality, the BitArray is just an array of Boolean Values (which would be the same size as any other boolean) that provides methods and functions useful in deconstructing System.Byte values into the BitArray and reconstructing the BitArray back into a System.Byte (same with System.Byte()).
I'd rather not go through a lot of code to restructure Boolean Arrays into BitArrays unless there's going to be some genuine memory-use improvement (which I'd expect to see if I converted large Boolean arrays - at 32 bits per index - into large BitArrays at 1 bit per index). I'm also interested to know if the Boolean is actually a 32 bit monstrosity.
I'm getting an error after sending a list to a web service.This is the code that is calling the web service:
Dim sProgramInterest As New List(Of Integer)
crmService.InsertProspectGetId(sProgramInterest.ToList)
But I'm getting this error.
[code].....
I recently implemented a solution to take an SSIS package and reconfigure the connection strings of the package using VB.net.[code]...
View 1 RepliesI am trying to change the image in a picture box using a combobox with item collections 0-8.When I run the program no matter what I choose in the combobox it selects case 0 and willnot change. code below for selected index changed.
Private
Sub ComboBox1_SelectedIndexChanged(ByVal
sender As System.Object,
ByVal e
[code]....
I am trying to solve an issue in my application where the following exception is occurring: there is already an open datareader associated with this command which must be closed first. I am using TableAdapters, which maintain their own DataReaders, and everything seems to work fine unless I am interacting with one of my background workers.
In my code, I shadow the Item property of my collections so that I can retrieve the actual data from the database if needed. Here is a sample:
[code]...
Now each reference to the Item get property instantiates its own DataAdapter, so I am confused as to how the same DataReader will ever be used in this scenario. Is there something I am missing? All the TableAdapters do in fact use the same connection object, but I wouldn't think that would be a problem
I am having trouble developing an asp.net page. I can create custom collections and use them in win apps, but when i reference the system.collections namespace, the page response hangs up. No exception info is passed back or anything. The page just freezes. Is this a common problem. I am wondering if its due to the assembly not being present (but am unsure why an exception wouldn't indicate this.).
View 1 Repliesimagine i want to add an extension method to System.Collections.Generic.List(Of T)
let's say i want to give it .GetUBound which returns Count-1
ok this code will save data withc is URL from textbox and load it to listbox , but i want it save first name of uRl like google then in other textbox put URl and save so when its load data its shows only name like Google not [URL] in listbox sometimes the link is too long and it will be not good interface in form1 and then when u click Google in listbox it open its URl [URL]
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
My.Settings.FavList.Add(url_text.Text)
[Code]....
I have a lists of different custom classes and each must be sorted severals times before the algorithm is complete. For each sort I wrote a comparer. Sofar so good. Everything works. But: By now I have abou a dozen different comparers in more than one class and it is still getting more. I wonder if there is a way to limit the number by writing a new general function that can be used to sort all lists without the need for a specific comparer.Below is what I've got so far. But it does not work.
"System.Collections.Generic.List(Of ClassA)" can not be converted into "System.Collections.Generic.List(Of Object)."
[code].....
Public extreme_foods As New System.Collections.ArrayList()
[Code]...
anyone know why extreme_foods(i)=s is giving INDEX OUT OF RANGE??
I have a fairly lengthly block of code that I'm trying to convert from VB6 to VB.NET. The ArcObjects GIS code basically looks at a table and groups a bunch of GIS layers together and adds them to the ArcMap table of contents. I'm having trouble with this line when testing it in Visual Studio 2010: [Code]
View 1 RepliesI am trying to pass a System.Collections.Generic.List to another class. The collection is created in class2 and then passed into class1
[code]...
However I get a 'Null Reference Exception error' when I run the program. It seems f_str in the line 'For Each s As String In f_str' is null.
I am planning to use a List in my application but when I was searching for System.Collections.Generic, it only has System.Collections. I tried to look it up in the "add reference" and its not there.
View 2 RepliesFirstly, i have a grdData at my main page. After choosing the data i want and went to another page using
[Code]...
how to find a value in the System.Collections.Generic.List.I have:
Private ids As New List(Of Byte())
ids.add(New Byte(){&HA8,&H0F})
ids.add(New Byte(){&HFF,&H03})
ids.add(New Byte(){&H10,&H00})
I would like to find for example: &H10,&H00 in that list and if there isn't the stuff I wan't to find then how do I know that?
I need to be able to tell if a property is of type List(of T)but am currently unable to. if i do
TypeOf (UpdateTo.GetType.GetProperty(node.Name)) Is System.Collections.Generic.List(Of Object)
I get the following error
TypeOf (UpdateTo.GetType.GetProperty(node.Name)) Is
System.Collections.Generic.List(Of Object) Expression of type
'System.Reflection.PropertyInfo' can never be of type[code]......