C# - Convert Datatable To Corresponding "named" And "typed" IEnumerable For Intellisense?
Apr 24, 2012
Possibly a dup but I tried googling and searching here before posting. Assume a 2 column table with columns Age (int) and EmpName (string) A datatable can be converted to IEnumerable by a simple dbTable.AsEnumerable() Now to perform any Linq you must know the column names since intellisense will not pick it up due the fact that AsEnumerable has returned a bunch of datarows that you can enumerate. I have used a small 2 col table but for tables with many columns it is a pain. So most of the time we try something like
I have an object called Result<T> that has a constructor which accepts an argument of IEnumerable<T>. I'd like to be able to pass in a datatable if possible.
I tried datatable.AsEnumerable(), but where I bind to the data it was complaining that 'MyProperty' is not a field or property on type 'DataRow' - which makes sense since 'MyProperty' isn't a property on 'DataRow', but it was a column in my datatable.Is there a way to convert a datatable to something that I can pass into the Result object and still have it bind to, say, a gridview?
The following line is giving me an InvalidCastException when trying to convert to IEnumerable type, even though I have implemented IEnumerable interface. Return New CountryInfo(CountryCodes(i), CountryNames(i)) (also in bold below)
Imports System Imports Gaia.WebWidgets.HtmlFormatting Imports System.Collections.Generic Imports System.Globalization
I'm wanting to have some datatables that are just used temporarily, mainly for creating and listing friendly versions of data that will be easier for the user to read in drop-down combos etc.
I would like them to be strongly typed to pick-up bugs at design-time. However I'm struggling to know how to achieve this. Do I need to create a custom class and inherit from DataTable and build the columns in the class constructor?I don't need a Dataset, just a DataTable?
I have a function that searches AD for members of various groups. If I remove the loop, I don't get the error "A column named 'cn' already belongs to this datatable", however, I need to iterate through each OU.
Function getCOMDLNames(ByVal searchStr As String) As DataTable Dim MySearchRoot As DirectoryEntry = New DirectoryEntry("path", "usr", "pwd") Dim MyDirectorySearcher As New DirectorySearcher(MySearchRoot)
Dim myRow As BurnerService.OEBSContractBatchesRow Dim myDate As Nullable(Of DateTime) myRow = Me.BurnerService.OEBSContractBatches.AddOEBSContractBatchesRow( _
I tried using the linq Zip method on IEnumerable but it does not work for more than 2 arrays.Here is an example in Python of what I am trying to do(I got p - nested IEnumerable - and need q - another nested IEnumerable):
I have an ASPX page (with VB Codebehind). I would like to extend the GridView class to show the header / footer when no rows are returned. I found a C# example online (link) (source). However, I cannot convert it to VB because it uses typed events (which are not legal in VB).
I have tried several free C# to VB.NET converters online, but none have worked.convert the example to VB.NET or provide an alternate method of extending the GridView class.Notes / Difficulties:
If you get an error with DataView objects, specify the type as System.Data.DataView and the type comparison could be the following: If data.[GetType]() Is GetType(System.Data.DataView) Then Since the event MustAddARow cannot have a type in VB (and RaiseEvent event doesn't have a return value), how can I compare it to Nothing in the function OnMustAddARow()?
I created a DataSet using the DataSources wizard. I can display the rows of each Datatable one at a time. But in this case, I needed to add a new DataTable (newDT) using the Add New Table Adapter control(?) on the toolbox. newTable is derived by JOINing three different existing tables (or, dataTable) in my DataSet designer. The query works fine and returns all the data as expected. Trouble, if I try to display the rows of the newDT on textboxes, I get a NULLREFERENCE Exception.
I'm trying to do a LINQ Query against a typed datatable that will return me duplicated data.With out going into too much detail, here's the basic setup:
strCode1 - string type intCode1 - int32 type intAdjustor - int32
There are more fields but these are the ones that are important.I'm going to do my best to describe this, as it's kind of confusing.In theory intCode1 is a key for strCode1 (hence the names). So each time intCode1 is duplicated, the same strCode1 should appear. Example:
[code]...
Ultimately I'd like to get a List(Of T) - where T is my typed data row. In SQL, I would simply use a sub query, to get a distinct list of strCode1 and intCode1, then do a count, grouped by strCode1 where I get more than one row.I'm not sure how to translate that into LINQ, AND get the original types data rows returned in a list.
I'm starting to learn ASP.NET MVC and since I work in a VB.NET shop I'm converting an example from C#. I'm trying to implement a strongly typed view and the example I'm looking at shows the following:
I have a fairly large project (Point of Sales) written in VB6. It has beenused successfully a 2 stores since 2001 (with updates of course).I would like to convert it to VB2008 (although I know about VB "fusion") just to keep it up to date and modernize it a bit.Since using the VB converter brings up such a lot of junk, I'm rewriting each module and form from scratch (although using as much of the original code as possible). One of the functions I'd like to retain is typing in a textbox, and converting each keystroke to upper case as it is typed.Here's the code I use in the VB6 version:
Private Sub txtDescription_KeyPress(KeyAscii As Integer) Call EnterToTab(KeyAscii) Char =
I am trying to make an app the will convert messages so if I type "ab" message box shows "zy"? Public Class Form1 Private Function ggg(ByVal kinglatest) As Boolean Dim newletter As String = "" If kinglatest = "a" Then newletter = "z" End If [Code] .....
How would I code a TryParse to get the input from customer from a textbox named Strands and convert it to a number (this number will always be a whole complete number, cannot be 5.6 or 4 1/2 or whatever) then have that Strand number be muliplied by the selected item in my listbox1. This listbox has an access database bound to it with 2 columns Size and Area, the Size equals the Area and I set the Value to the Area column but set the Size to show up in the list box. and the Strands textbox has to muliply by the Size picked, but by the Area # not the Size #. And the results of that multiplication showing up in another textbox named total.
I am finding difficulties to convert a datatable to a new datatable using a reference datatable. My question is confusing and I am not good at explaining things so I drew a picture (see below).I have two datatables on memory and I need to create the third datatable using the second mapping table for reference. The column names are just for example and it can't be hardcoded.
When the user clicks an "Edit" button on my form, I want a box to come up which allows the user to edit a DataTable in a strongly-typed DataSet. What's the best way to do this?
I have read many posts on this topic; among them and most recently .NET - Convert Generic Collection to Data Table. Unfortunately, all to no avail.
I have a generic collection of structures :
Private Structure MyStruct Dim sState as String Dim lValue as Long Dim iLayer as Integer End Structure
Dim LOStates As New List(Of MyStruct) I need to fill a DataTable with this list of structures but have no idea how to go about doing this. I am using vb.net in Visual Studio 2008.
I have seen many examples of populating a listview from a datatable or converting a datatable to a listview but what I am trying to do is exactly the other way around.
How can I convert/copy the contents of a winform listview to a datatable?
[EDIT]
I have a listview with a context menu where users can multiselect items and choose one of the context menu options, I then loop the selected items and extract each selected row (listview item) and serialize it, instead of doing this I wanted to convert the listview to a datatable then add the datatable to a dataset and serialize the dataset.
convert a dataTable to List(of T).In Vb.net on .Net 3.5 If you know How To or maybe a link of somebody who did it.I check this on c# (from another stack question)
public static IEnumerable<T> ToEnumerable<T>(DataTable dt, Func<DataRow, T> translator) { foreach(DataRow dr in dt.Rows) {
I am trying to import a large array of integers stored as a csv file into a VB.Net DataTable called BeamMap. The .csv file consists only of integers, with a delimiter of ,, no quotes around the data (ie., 1,3,-2,44,1), and an end of line character of line feed and carriage return. All I want to do is get each integer into a DataTable cell with the appropriate rows and columns (there are the same number of columns for each row) and be able to reference it later on in my code. I really don't want anything more than absolutely necessary in the code (no titles, captions, headings, etc.), and I need it to be fairly efficient (the csv array is approx. ~1000 x ~1000).
I managed to Convert a Datagridview to Datatable, Now problem is the programmatically addded Columns Seem to end up at the end of the of the initial table layout[code]...
i am using following code to convert xml file to datatable but its just creating multiple tables (but without data) and i want tables with data..
Dim myDS As New DataSet Dim xmlStream As System.IO.StreamReader = New System.IO.StreamReader(Server.MapPath("~xmldoc esult_availhotel.xml"))[code].....
I have a question about converting a datareader to a datatable. In my code, I have a datareader created in one class and passed to another class that I want to convert it to a datatable.
When I do this, it does not seem to work, as the table remains empty. If I do the conversion in the same function, it works fine.
Its only when I pass the datareader to another function that it stops working. Is this because the dr is closed or something? How do I overcome this problem? Any help would be great.
I am getting this error cannot convert string to datatable
The code is
dt = CType(Session("result"), DataTable)
I am trying to store the session value in dt which is a datatable. The session result contains string values.how to convert the session to datatable and store the session value in the datatable.
data table contain column named as Fld_primary. this column contain value like 0.00 it is double datatype in mysql table.i want store that datatable value in double variable. am always getting error when i convert to double datatype.
my code ------- Dim ds5 As dataset1.DTSUMDataTable = TA5.GetData(users) Dim dttot As Double dttot = CType(ds5("fld_primary").ToString, Double)
Error:Conversion from string "fld_primary" to type 'Integer' is not valid.
