Use Generic List Where By Instance / Index?
Jun 3, 2010How to use Generic List Where method based on index if there are mutiple 'similar' values, see example below
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Search A Generic List - Keep Getting:Delegate To An Instance Method Cannot Have Null 'this'?
Feb 16, 2009I'm trying to search a generic list of 'User' business objects which has a property called 'Username': If (From u In colUsers Select u.Username Where Username.Equals(strUsername)).Count > 0 ThenI keep getting:Delegate to an instance method cannot have null 'this'.
View 16 RepliesInvoke An Instance Function Delegate On An Instance Of A Generic Type?
Aug 4, 2010D is a dictionary whose entry values are of Type T..What I'm attempting to do is have a delegate like "Serializer" below that I can invoke on an instance of T, such as "Entry.Value" below.Please see the "return Entry..." line below for my wishful thinking.[code]
View 2 RepliesGeneric Cannot Instantiate Instance Of The Generic Type With New?
Feb 8, 2012I am trying to write a generic method, to avoid code duplication, which will create or activate a Form as an MDI children, based on its type. But I have to lines in error (see comments).
[Code]...
.net - Creating A Generic List Of A Generic Type
Jun 30, 2011I am trying to create a list of a generic type in vb.net 2.0 framework.
This is the generic type definition:
Public Class GenericParamMap(Of T)
Public Sub New(ByVal pParamName As String, ByVal pPropValue As T)
mParamName = pParamName
[Code]....
The compiler does not allow a "T" in the method's parameter because it's not defined, but I'm not sure how or where to define it. I thought it was okay to have a generic method definition.
Declare New Instance With Generic Type?
Jan 26, 2009I have two class like this[code]...
The red code does not works. How do I get the type of data to declare, for example, a Specific Instance(Of integer) if Data is integer, and also Specific (of SomeClass) if Data is SomeClass?
How To Determine If Value Is Instance Of Generic Type
Mar 27, 2010I have a class C(Of T). I want to determine if some given value has type C, regardless of what T is. For example, I might want to determine if a value is a strongly-typed list, regardless what type of items the list stores. I just need to know how to do it in VB.net. In Java the syntax is like this:
var result = obj instance of Gen2<?>;
Index Out Of Range Exception In Custom Generic Collection?
Feb 25, 2009I wrote a class which imports System.Collections.ObjectModel. For the management of the collection, I've written:
Default Public ReadOnly Property Item(ByVal vntIndexKey As Integer) As ItemType
Get
Return CType(mCol.Item(vntIndexKey), ItemType)
[code].....
Determine If Property Is Generic List<of T> Via Reflection And Loop List Items
Oct 1, 2009I'm looping all the properties in an object via reflection:
For Each p As PropertyInfo In values.[GetType]().GetProperties()
If p.CanRead Then
'Do stuff
End If
Next
how to determine whether the property in question is a generic List(Of T)? If it is I need to loop the list itself.
I've experimented with GetType and TypeOf but have not managed to get anything working.
To clarify, I want to keep this generic. I do not want to specify the type of T, I need to loop the list items and call the ToString method on each item. T could be one of a number of different types (application specific reference types). Is it possible to do this without specifying types?
(VB.NET 2005 with .Net 2.0)
Get Type Of Derived Generic List Class From List Item Method?
Mar 23, 2011Public Class notifierMain
Public Class Contacts
Inherits List(Of row)
Public Sub New()
[code]....
When I debug this winforms application I get curType = "notifier.notifierMain+Contacts+row" I want to the Validate function to know it is in MyContacts. How do I do this?
.net - Returning A List Using Entity Framework, 'System.Collections.Generic.List Cannot Be Converted To '1-dimensional Array
May 3, 2012i have issue returning a list in a web method. here is the code
<WebMethod()> _
Public Function getTags(para_parents As String) As List(Of getTypeDetailsByParentName_Result)()
Dim context As New PPEntities
[code]....
the error is
Value of type 'System.Collections.Generic.List(Of SaftyonRoad.getTypeDetailsByParentName_Result)' cannot be converted to '1-dimensional array of System.Collections.Generic.List(Of SaftyonRoad.getTypeDetailsByParentName_Result)'
Pass Generic List To A Function That Has A Custom Defined List
Apr 7, 2011it seems always at this time I cant figure out how to do something maybe it has something to do with lunchtime.
Im having trouble using a method that is defined by an outside company
This is a link to their integration guide:
[URL]
This is their documentation for the class Im trying to use
OrderQueryWebService Class
This class is for SID in particular and is made for use with the notification methods. This is for the Order Query Web Service specifically, allowing clients to return the status of transactions for their merchant, whenever they want to.
Methods
/ <summary>
/ Pass through the variables required and receive a list of Transaction
objects showing transaction status
[Code].....
The MerchantCode, the MerchantUsername, the MerchantPassword are all good the List is a custom type called SetComHash.Transaction
Everytime I try adding a string to the list such as the transactionNumber and some other values it gives me a type error:
"Value of type string cannot be converted to 'SetcomHash.Transaction'
C# - .NET Generic Class Instance - Passing A Variable Data Type
Jun 2, 2010I'm tyring to pass a variable data type to a template class. Something like this:
frmExample = New LookupForm(Of Models.MyClass) 'Works fine
Dim SelectedType As Type = InstanceOfMyClass.GetType() 'Works fine
frmExample = New LookupForm(Of SelectedType) 'Ba-bow!
frmExample = New LookupForm(Of InstanceOfMyClass.GetType()) 'Ba-bow!
[Code].....
I'm assuming it's something to do with the template being processed at compile time but even if I'm off the mark there, it wouldn't solve my problem anyway. I can't find any relevant information on using Reflection to instance template classes either.
(How) can I create an instance of a dynamically typed repository at runtime?
.net - Sort Generic List Based Upon A Different List?
Oct 29, 2010What would be the fastest way to sort a list that contains a list of objects, based upon another list? An example follows:Say I have multiple lists of employees. Each individual list has a common property value, say "Department". So I have a list of employees, in one list they all have the department string value of "Sales". In another list all the objects have a department value of "Finance". These lists of employees are then contained in a list which holds them all.
I have a second list, which should drives the sort order of the employee lists. The second list simply contains a list of strings like, "Finance", "Sales", "IT" and so on. I'd like my lists of customers to be sorted in the order of "Finance", "Sales", etc.I'm using VB.NET in .NET 2.0
Determining The Index Of A List Based On Another List And Vice Versa?
Jan 6, 2012Suppose you have list 1 (ilist1) and list 2 (ilist2) both lists have 3 items.
At index 0 item1 which has text "-- Select --"
At index 1 item2 which has text "Yes"
At index 2 item3 which has text "No"
Both lists have identical items. I would like to know if it is possible to have the selection of list one be "Yes" and the selection of list two be "No" and vice versa using SelectedIndexChanged or something of the sort.
For example:
ilist1 = --Select--
ilist2 = --Select--
[Code]....
Generic TypeOf Operator - See If List Is A List(Of T) Variable - Error: "Type Expected"?
Jan 5, 2011Dim x = GetType(List(Of )) 'valid statement
Dim list As New List(Of String)
Now I want to see if list is a List(Of T) variable: Dim isList = TypeOf list Is List(Of ) On the last line I get a compile error: "Type Expected". Is there any cheap-performance TypeOf operator alternative for generics?
Error - Red "List" Says Too Few Type Arguments To System.Collections.Generic.List(Of T)'
Mar 12, 2009I have converted c# .cs to vb:= I have 6 errors on:
Red "List" says Too few type arguments to system.Collections.Generic.List(Of T)'
Orange "Calendar" says Value of type 'System.Windows.Forms.Control.ControlCollection' cannot be converted to 'Form1.Kobush.Windows.Forms.Appointment'.
[code]....
Warning: Type Library Exporter Encountered A Generic Type Instance In A Signature
May 5, 2009I'm compiling a VB.Net 2.0 app (created in VS2008) using msbuild, and now I've added a generic return type, it's giving me the following:
Warning: Type library exporter encountered a generic type instance in a signature. Generic code may not be exported to COM.
Having just spent ages removing all of the previous warnings, I don't really want to add a new one. Any idea how to get rid of it (aside from not using generics)?I don't know what details I'd put in the attribute, or what number to put in the project-level ignore list.
Asp.net - Find The Max Id From A Generic List?
Oct 13, 2011i m getting a collection of data in list's object. And from this list i want to get the maximum id.`
Dim objinfo As List(Of AlbumInfo) = objPhotos.GetPhotos_Alb_ID(Me.ModuleId, hdd_AlbID.Value)
Dim Photo_Image As String = ""
Dim str As String = Photo_Image & fu_Photo.PostedFile.FileName.Substrng(fu_Photo.PostedFile.FileName.LastIndexOf("."))
[code]....
this returns the "0"th positions id from Convert.ToString(objinfo.Item("0").Photo_Id + 1)but i want to get the last item's id.
C# - Sum Of A Column Of Generic List?
Jan 5, 2011i have list of string like this :
Dim totalPrice As New List(Of Integer)
how can i get sum of column(0) (C# or VB) ?
Generic List, Add, And Same Values?
Jan 17, 2011<div class=PhorumReadBodyText>Hi, I have a problem with adding of items to generic list, problem is when I insert 1. item to the list, everithing is ok, but if I insert second item, first and second has same values.
code looks like that (asp.net 4.0): </div> <div class=PhorumReadBodyText> </div> <div class=PhorumReadBodyText>Partial Class _Default
Inherits System.Web.UI.Page
[Code]...
How To Add Items To Generic List
Jan 17, 2011I have a problem with adding items to generic list, problem is when I add 1. item to the list, everything is ok, but when I add second, first and second has the same values...
This is code (asp.net 4.0):
Partial Class _Default
Inherits System.Web.UI.Page
<Serializable()>
Public Class Product
Shared Property Material As String
[URL]
Loop Through Generic List
Aug 26, 2009In my VB.net application I am populating my customer object and looping through it as shown below.As there are thousands of customers, I want to do it 500 customers at a time.Is there anyway I can have one more For loop to process 500 customers at one shot in vB.netI am not using LinQ as the database is Oracle.[code]
View 2 RepliesLooping Through Generic List?
Apr 30, 2010I want my loop to loop until it reaches the last string in my generic list. I know I could simply insert the last index of the list as an integer but I want to be able to use this if my list grows too. How could I achieve this?
View 5 RepliesSearching A Generic List
May 14, 2009I have been reading extensively about searching generic lists in VB.NET with the usage of delegates.However, I still cannot seem to grasp how to achieve what I want to, which I believe is frustratingly simple! I have a list populated with instances of an object with three parameters (fields/ variables).When I receive a new object to add to the list I want to search the list for the "layer" field.If the field matches then I will replace that row (object) in the list with the new object, if no match is found then I will add it to the list. [code]
View 3 RepliesSplitting A Generic List?
Jun 11, 2011i have a generic list of type datarow.i have to split this list at an index and then use both parts of the list.
View 2 Replies.net - GroupBy 2 Values In A Generic List?
Aug 18, 2010I'm using VB.NET on Framework 2.0. I'm looking to quickly group a Generic List<> by two properties. For the sake of this example lets say I have a List of an Order type with properties of CustomerId, ProductId, and ProductCount. How would I get the average of ProductCounts grouped by CustomerId and ProductId in VB.NET ?Unfortunatly I cannot do this at DB level (which would have been easy). Also I cannot use LINQ or Lambada as Im on Framewwork 2.0. So I need to do this at application level in VB.net. The list is returned to me sorted by CustomerId and ProductId so I guess with a few loop sI should be able to create a average value for but there must be a cleaner way to do this?
View 1 Replies.net - Iterating Through Generic List Of String?
Jan 28, 2012I have the follow code in my program where I hit a SQLCe database to append the results into a list. That part works, but instead of exiting the function 'QueryDB' it goes to the else statement and runs the function again, which will return a null value. I designed it this way becuase I wanted to check to make sure the database is open before I try to execute the SQL statement, and if it's not open, call the method to open it and run through the function again.
[Code]...
.net - Sort Generic List On Two Or More Values?
May 15, 2009We have a generic List(Of Product) that must be sorted on two or more properties of the Product class.
The product class has the properties "Popular" numeric (asc), "Clicked" numeric (desc), "Name" string (asc). In order of naming the properties we want the list to sort.
How can it be sort with an lamba statement? If have found to sort the list based on one property.
Add Custom Class To A Generic List?
May 10, 2010I created two classes. One class is StudentClass and the other is HomeroomClass. The HomeroomClass contains a readonly property as a generic list of the StudentClass. [code]...
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