I am using VB .NET 1.1 and wanted to make sure if inside a key value pair class "Dates" (collection type) a key by name "TerminationDate" exists.
If Not Dates.Item("TerminationDate") Is Nothing Then
'Do x y z'
End if
But this is throwing an exception: Argument Index is not a valid value.
while entering in a textbox the collection is narrowed in datagridview. I have read that sqldatareader is faster than a sqldatadapter.
View 1 RepliesI've got the following ADO.NET Entity Framework Entity Data Model:I want to find all the Policyholders with both a Service of a given Id and also a Keyword of a given Status.
This LINQ Does Not Work:
Dim ServicesId As Integer = ...
Dim KeywordStatus As Integer = ...
Dim FoundPolicyholders = From p As Policyholder In db.PolicyholderSet.Include("Keywords").Include("Services") _
Where p.Services.Id = ServicesId _
And p.Keywords.Status = KeywordStatus _
Select p
The Where clause cannot search the p.Services and p.Keywords EntityCollections in that way.
[Code]...
search the collection of a collection in my LINQ Where clause?
View 11 RepliesHow can I search, for example ID Number, and want to highlight the listview item found in search from my first form? I'm using combobox from my second form to search.
View 6 RepliesNearly identical to How can I get every nth item from a List<T>?But I'm having trouble turning
List<T> list = originalList.Where((t,i) => (i % 5) == 0).ToList();
Into VB.Net code.
I am trying to make it so when I use Me.Controls("Timer1") for example I can access specific commands for a timer such as Stop() Start(), I tried CType() and typed in "Timer" as the type but it says the control type can't be converted to the "Timer" type.
View 11 RepliesI have created collection and adding values in the collection, later I need to find if uer passed value is exist in the collection or not, I use contains finction to find the answer but it always returns false even though user passed value exist in the collection list. here is my code:
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This is my code.Private Sub cmdDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdDelete.Click
[Code]...
I want to do something different on the last KeyValuePair of the Dictionary I'm iterating on.
For Each item In collection
If ItsTheLastItem
DoX()
[code].....
Here is an example of my xml doc:
<?xml version="1.0" encoding="utf-8"?>
<employeedata>
<employee>
<firstname>Bob</firstname>
<lastname>Anderson</lastname>
[Code]...
However, only the first phone number (Office) displays in the listbox. The phoneinfo collection has both <phone> elements, but the For Each statement doesn't seem to iterate thru.
Is there a way to remove 'this' item from a collection, i.e the one I'm working with, or do I always need an index?
For each ThisItem in MyCollection
if a=true then MyCollection.Remove(ThisItem)
next
[code].....
I'm building a WP7 (VB.NET) app and have a custom class, PinInfo, of which I have two ObservableCollections, TempPins and FavoritePins.
In various parts of the app, I need a unique identifier to get a reference to a particular PinInfo in the collection, so at present, I assign an ID to the PinInfo when it's added to the collection, then later get a reference to the pin via the ID.
For example, if I create a button to delete a pin, I set its tag to the pin's ID, then the button click handler reads the button's tag to get the corresponding pin from the collection (via LINQ).
I generate the ID by adding one to the last-assigned ID, but these lists are often modified (i.e. items removed), so I end up with needlessly large ID numbers (e.g. just a few items, with IDs in the thousands).
I have a collection as such
Private Shared ReadOnly thermoPaths As New ReadOnlyCollection(Of String) _
({
"thermometer_000_108x320.jpg",
"thermometer_010_108x320.jpg",
"thermometer_020_108x320.jpg",
"thermometer_030_108x320.jpg",
[Code]...
Is there any way to get the index of the changed item? I couldn't find any examples.
View 1 RepliesIn a list of timers, how do I determine the index of the item that elapsed without having to iterate the collection as shown below (e.g. can I pass a paramater to OnTimedEvent, or can the collection raise an event to say which item fired???). It's the individual timer index that I need as I'm using it to refer to something else.
(I wont know how many items I'll have in the list in advance so I can't create an individual event handler for each timer - I don't think I should even if I did).
Public Class Form1
Private _timers As New List(Of System.Timers.Timer)
Private Sub Form3_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
[code]....
Can I use LINQ to return an item in a collection that is the same TYPE as the items in the collection? I am a LINQ Noob trying to avoid looping.
Dim mostRecentlyCreatedQuestionnaire As ParentQuestionnaireItem =
CType((From P In questionnaireCollection Order By P.Metadata.CreateDate Descending).Take(1), ParentQuestionnaireItem)
I get an "unable to CAST" error when I include the CTYPE function. I kind of expected that error, but I imagine that if I coul dnot do this, LINQ's usefulness would be diminished and therefore assume that there must be a way..
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 RepliesI am creating a simple website using the language of VB.NET, I am having trouble with one part at the moment and could really use some help.
At the moment I have items that are stored in a database, when the homepage loads these items are added to a Gridview which allows the user to select the items they wish to add to their shopping cart. Once an item is selected from the gridview it is added to a collection. That collection is then added to a Session. This is the code I have for completing that task.[code]...
I want to create a very simple database. form1 - ListBox1, textBox1, buttonadd, buttonremove. The item collection of the ListBox1 is stored in a txt file along with a string that will be displayed in the textbox1. the file will look like this ( like a .ini file):
[Code]...
I have a parent child collection objects and was wondering how to get a single item from the child collection using Linq
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I am doing this within a thread:For Each item As ListViewItem In lvUsers.Items and I am getting: Cross-thread operation not valid: Control 'lvUsers' accessed from a thread other than the thread it was created on.I have been able to adjust a control in a way using something like:
Public Delegate Sub ListAddNameInvoker(ByVal text As String)
Public Sub ListAddName(ByVal text As String)
If lvUsers.InvokeRequired Then
[code]....
But how do I get data from a control and pass it to another thread?
GetDocumentType() works fine but adding into the collection cause error, it is not adding anything into it.
Imports System
Imports System.Collections.Generic
Imports System.Collections
Imports System.Collections.ObjectModel
[Code] .....
How can I make a comboxbox list the first item in the collection by default in other words i have a collection list
1
2
3
4
5
When program loads I want combobox to load 1
I have a class that contains a collection of another class. See below
Public Class Spot
Private mActive As Boolean
Public Sub New()
[Code]....
I can't figure out how to determine the type of an object in a collection. I want to do a For Each ... Next loop over the items in the DropDownItems collection of a ToolStripMenuItem. For those items that are ToolStripMenuItems themselves I want to take some kind of action. (The collection can contain other types of items, such as ToolStripSeparators). So I need to say something like: If Typeof(item) = ToolStripMenuItem Then .
View 1 RepliesI have recently started .NET programming, and looked at both VB.NET and C#. In VB.NET, a strongly typed Datatable cosisted of a collection of strongly types rows. Therefore, for example, this statement would work:
lCustomerTable As CustomerDataSet.CustomerTable
lCustomerRow as CustomerDataSet.CustomerTable.CustomerRow
lCustomerTable = TableAdapter.GetData
lCustomerRow = lCustomerTable.Rows(0)
However in C#, it seems i have to explicitly cast the returned Row to a CustomerRow:
lCustomerRow = (CustomerDataSet.CustomerTable.CustomerRow)lCustomerTable.Rows[0]
Should the dataset not create the object type definitions when creating the table adapters and SQL dataTables?
I'm OK with both C# and VB.NET..I have a function GetListOfBook, that returns LINQ to SQL result that has a collection of objects like the following:[code]
View 4 RepliesI have a small piece of code that iterates through the controls collection on a panel (below) Everything works fine until I want to focus on a control that doesn't support the selectall method i.e. a datetimepicker. Is there any way of determining the type of control and not call the selectall method when the type is datetimepicker. All my other controls support it so that's the only one I need to exclude.
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this is more a theoretical question i asked myself.I remembered that BinarySearch of an ordered List(Collection in general) is faster than finding Rows with Datatable.Rows.Find or DataTable.FindByPK with a primary key value.Hence i fill a Datatable from Database in a shared constructor and immediately after that a List(of Int32) that contains all primary keys from that table. Later i will check with BinarySearch if the List contains primary-key values. But because the datatable contains only the PK-Column anyway, i asked myself if there is a way to avoid the huge overhead of filling a Datatable and after that adding all Rows to a List. Is it possible to fill a generic List(or other collection-type) instead of a Datatable/Dataset directly from a Dataadapter?Maybe i'm off the track and there is another way to avoid the Extra-Loop that i'm missing.
The code of filling the DataTable in a strong typed Dataset and the List:
Private Shared w205CorrectSWUpgrades As New List(Of Int32)
Shared Sub New()
[code].....