.net - Transform List(Of DerivedObject) To List(Of BaseObject)?
Apr 3, 2012I have a fonction that operates a list of base objects. But I have a list of derived objects. What is the most efficient way to transform it?
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I have a fonction that operates a list of base objects. But I have a list of derived objects. What is the most efficient way to transform it?
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I have a list(Of transaction) :
[Code]....
How can I transform it to a list(Of transactionShortened) :
[Code]....
I need to copy an array to a linked list OR transform the array in a linked list.How this can be done in .NET (C# or VB)?
View 3 RepliesSuppose I have a list of Cat.
Public Class Cat
Public Property id As Guid
Public Property name As String
Public Property race As catRace
End Class
How can I quickly transform this List(Of Cat) into a List(Of Guid) using the id property?
I could do :
Dim newList As List(Of Guid)
For each item in catList
newList.Add(item.id)
Next
But I think there must be a way to do this faster (1 LOC). I just can't find how.
II am trying to create a toggle button that switches a list to a range and then back to a list if needed. I am able to get it to do both but when I add an item to the list, convert to a range and then convert back to a list it leaves off the last items I entered.I tried to work in a code to select all cells but I must not be putting it in the right place.This is what I have so far:
ActiveSheet.ListObjects.Add(xlSrcRange, Range("$A$3:$AE$7"), , xlYes).Name = _
"List1"
I realize the problem is the $AE$7 (the $A$3 is correct)
In VS 2008, VB.Net, I am successful connecting to a local SQL Server (version 8) and seeing all tables/views/procedures in Server Explorer. The local OS is Win XP Pro SP3. I created an ODBC data source to a remote SQL server (also version 8) with a database of the same structure as the local one. The connection tests out ok. The remote computer runs Windows Server 2000 SP4. In the VS 2008 Server Explorer I add this ODBC source. When I click on the plus-signs to expand items, neither the tables nor the views show anything, whereas the full list of procedures appears. Is it the old SQL Server version? Is it the old Server OS version? Something else alltogether?
View 2 RepliesThis is what I'm sure will be the first of many noob-ish questions from yours truly... I'm studying as a mature student for a Computing Degree (encompassing web design, hardware, programming and systems analysis). The programming seems to be my weak spot this year. I enjoyed C++ last year, doing basic console applications, but progamming visually with VB in Visual Studio 2008 I'm struggling!
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Does link text mean I have to return a concrete implementation? Even though I am using svcutil with the /r that includes my entites(where IMyInterface is defined). I get no errors but it changes all List(of IMyInterface) to list(of Object) and I cannot deserialize it on the client
Error: list(of object) cannot be converted to list(of IMyInterface).
I'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)
If I can generate a list of random integer with a click of the button and put the results in a list box using VB.Net but how do I randomly change several integer number generated by button 1 by clicking button 2? How I retain the results of button1 and change the results when clicking button2?I try before but the two button function code cannot relate to one another.
View 1 RepliesPublic 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?
In VS 2008, VB.Net, I am successful connecting to a local SQL Server and seeing all tables/views/procedures.I created an ODBC data source to a remote SQL server with a database of the same structure as the local one.The connection tests out ok. In the VS 2008 Server Explorer I add this source. When I click on the plus-signs to expand items, neither the tables nor the views show anything, whereas the full list of procedures appears.How can I see the lists of tables and views in Server Explorer for an ODBC source?
View 1 RepliesI wish to make a project where a teacher views a list box with a list of students of a class. When he selects a name from the first list box the second listbox would change its data to show the grades for that one student.
View 10 RepliesI have implemented inheritance for two parent classes called Table and Field. Each parent class has several child classes. In the Table parent class, I created a method that expects parameter List(Of Field).
I get an error when trying to pass in parameter List(Of ChildField) to the method that expects a parameter of List(Of Field). The error message is as below:
Value of type
'System.Collections.Generic.List(Of
com.hlb.icisbatch.data.ChildField)'
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This program is supposed to allow the user to check items in a checked list box. If the item is checked, it goes into the Completed List Box on the right. The program then adds the unchecked items to the Pending list box on the left. I keep getting placement values (e.g. O,1,2) instead of the strings (e.g. "Key Returned") in the list box results (see photo attached)
Public Class frmCheckOut
Dim i As Integer
Dim cleaning As String = "Cleaning Inspection"
Dim damage As String = "Damage Repaired"
[code].....
Another program I am working on for fun, I am basically shuffling a list inside a listbox, what I want to do is delete the rest but not sure how to go through with that. At the moment I have this: [code] Just contains the code, declarations outside weren't included.So anyway, once clicked, it will call on the function to basically shuffle in a for loop, I was wondering if I should (or how should) create another function and call it in the click button or have just a loop in the click button so it deletes half the list. What I am doing is I have 20 list of items, I want the program to shuffle the items and then deleting the lower 10, meaning, if I had 10 items and wanted 5 top, I'd want: 0, 1, 2, 3, 4 and deleting 5, 6, 7, 8, 9.
View 7 RepliesI currently have a list of words in a text file sorted in to alphabetical order and put into lower case, but I would like to be able to also display the line numbers on which these words are associated with.. but only one instance of.
For example,
"This is a random text
file that I
have just made
up this second"
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As you can see above, I would like to show that "this" for example appears on line 1 and 4. Hopefully tabbed so that it keeps a nice look to it.
I think (?) this is about object design, and perhaps about structural and/or creational patterns. But a bit hard to say when I only know a couple of patterns yet.[code]But... what if we INSTEAD want each Product instance only to (in some way) refer to one instance of a specific list of Components. So we wan't to save the products list to one file, and the components list to another file. Then would I build the objects the same way, or different? So let's then say we have now Class B as below. [code]
1. Will not need to update each component variable of the products list when the components list changes.
2. If the Product object shall be shown in a DataGridView, for editing properties, it seems easier to implement the selection of the component property.
Is this wrong approach? Is it suitable in some cases, and if so, when? Are there other solutions I perhaps am not aware of that would be appropriate? Is this about structural design patterns? and if so, can the alternatives above be catagorized to some pattern type? I don't really know exactly what I'm looking for.. But I think probably I'm looking to understand whether the object design will be determined by the way the objects are saved.. And if i shall save the objects by serializing to file, vs saving to a database, would I create the business objects differently?
I'm getting System.NullReferenceException error when I try to add the employee info to the Employees list.
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I have a small problem i'm trying to fetch list of directoies from 1 special ftp server wich does not support LIST command i was try this code and it works for all ftp server i have try exept this special one :
'' Get the object used to communicate with the server.
'Dim request As FtpWebRequest = DirectCast(WebRequest.Create("ftp://" & txtFTPhost.Text), FtpWebRequest)
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I'm getting error 502 which means command is not supported and app crashed. I would just simple said leave it but i have try normal ftp clients like FlashFXp and it works just fine (i can see error in the log but it just pass it and show direcoties)
i 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)'
y have this class
Private Class MyClass
Public Property propertyOne() as String
Public Property propertyTwo() as String
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i am trying to create a list of list in that i would like to work on multiple accounts at the same time. lets say i have 5 accounts. every account has a seperate name. each account has a few fields. so i though of having a list of bookkeeping (with 5 accounts) and a list of accounts (with expense, income, tax, status, etc as fields). [code] and if the idea of using list of list works how do i loop through both lists.
View 6 RepliesI would like to create list of child objects from list of parent object. Like If i have list of bookingroom which has one member room then i would like to create list of room from it.
eg. code:
Dim BookingRoomList As List(Of BookingRoom) = New List(Of BookingRoom)
Dim RoomList As List(Of Room) = New List(Of Room)
BookingRoomList = BookingRooms.FillGrid()
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Is there any short cut method instead of iterating over for earch?
This is probably a really basic question - but I have a list of items (custom objects) being passed from one winform (.net 3.5) to another. I want to create a local list to store changes that only get persisted if the user clicks save. Currently if the user clicks cancel - the changes are still applied in the first form because I assume the objects are reference type.I have the save working as it calls a service layer to do the save and then refreshes the other form - but not the cancel.
View 1 RepliesSuppose 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--
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I am attempting to read the results from a SQL query into a List(Of) and I can see the List.count while adding items to the List increments, however in another part of my code when I am attempting to read the List the List.Count returns 0. My List is as follows:
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it 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
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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'
We're working on a big ASP.NETVB.NET website project. I need to populate three dropdownlists. To last two are independent of the previous ones. The population data comes from an SQL Server. I'd have no problem doing this with code-behind with post back but we don't want any PostBacks so I started to develop this in AjaxjQuery.
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I use a List(Of T) (where each T is a custom type with a few members) to keep track of about 500 items that change all the time. The list can be changed from different locations within the program (uses background workers that monitor the list).
Question: Is there some built-in way to prevent the List from being updated from different locations or from different threads at the same time? For example, one thread may remove an item from the list while another location changes one of the members of an item, causing conflict, wrong data and errors. Perhaps there is a standard way in VB.Net (framework) to solve this type of problem?
I use VB2008 (VS2008 Pro) and WinXP SP2.