I have a datatable being returned by my DAL. In my BAL I want to return a class object. So I have a class called BusinessArea that has ID, Description and Active properties. I tried this:
[Code]...
Datatable object within class function + garbage collection?
View 3 RepliesI have an array of unknown (to the current method) class objects. I do know that each class has a property called "Number". I am trying to write a LINQ query where I am looking for the object with the next Number in sequence. AKA, I'm at Number 8, use a LINQ query to find the object where Number=9.
View 5 Repliessyntax of the LINQ query to use GROUP something BY something and select some fields of the datatable. i am having a datatable filled with some rows, i am trying to fill the datagridview with the GROUP BY query output of some fields.
View 4 Repliesi need to query the datatable & set the outcome as datagridview controls datasource
vb.net
Private Sub Txt_Search_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Txt_Search.TextChanged
'routine objective:- Filter datatable & set the datagridview datasource
[code]....
I am trying to create an list or an array of a class.Here is my "Ingredient" class that I am trying to create a list of:[code]In my "recipe" class, I am want to create a list (or array) and I am drawing a big blank on how to do it. Can anyone point me in the right direction?
View 2 RepliesI'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've read (or the only book that covers ado 3.5) is Murach ADO 3.5 and throughout the book, the author recommends using object binding so that's what I've been doing. However, I had a chance to look at all the codes for our applications at work, and only datatables are used.Was curious as to the difference/pros and cons between binding to an object, and binding to a table. I guess my real question is which one should I be using, datatable or object binding? Is there a definite answer or does it depends on the situation and what I want to do?
View 3 RepliesI'm using the following code to sort a List(of Class) using LINQ. It works fine, but I'm wondering if there is a better way to do it. I'm basically taking one list, applying LINQ to it, then using the result to create a second list in the sorted order. Can I do this without creating a second list? Here is my sample
' KeyMatch is my Class Variable
' mMatchList is the Unsorted List
'
[code].....
I'm working on a helper class that will make things easier for me when connecting to and viewing a crystal report.Now I need to create a Property called DataSource. Crystal has a SetDataSource method that has 4 overloads/constructors(not sure what the right term is)1 accepts a System.Collections.Ienumerable, the 2nd accepts a Dataset, the 3rd a DataTable, and the 4th a DataReader.Now I want my property to be able to accept all those. So what Type must my property be.If I can just have DataSet and DataTable for now it would be fine, as I work with those mostly Public Property DataSource as?
View 3 RepliesI have the following xml document which would be taken from the web and stored into an XDocument object.
[Code]...
I am utilizing a centralized class object that needs to call another class object. The program itself will do something like the following
sFieldValue = CentralObject.ObjectHandler(1, TestFunction, "FunctionVar,FunctionVar2,FunctionVar3")
In the central object I have a function
Public
Function ObjectHandler(ByVal ObjectType
As
Integer,
[code]....
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
I have a select statement and it will go to a datatable object, I would like to do the following
textbox1.text=datatable(first field value)
textbox2.text=datatable(second field value)
textbox3.text=datatable(third field value)
I've got a form which is populated with text fields and listbox's etc. I've connected it to a database and i'm going to populate these with results from one selected row. Should I create a class object that will have a variable for each textbox and then in one function add or remove this object from each textbox Or Should I via a sub when selecting a row add each result to it's respected textbox.
View 5 RepliesI have procedure (Import) that calls a for a new instance of frmImportData. I also have a class name clsBatch that has a data table property called prpParametersTable.For some reason, I get an error (indicated below with ERROR>>>) when trying to assign prpParameterTable to cv_dtImport2. The error states "Object reference not set to an instance of an object.". Why does this error not happen when I assign dtBP to cv_dtImport1? Both cv_dtImport1 and cv_dtImport2 are equal to Nothing and in my Import procedure dtBP = prpParametersTable.
Public Sub Import(ByVal clsB As clsBatch)
Try
Me.cv_clsB = clsB
[code]....
I'm an intermediate student taking on a monopoly game for a summative project. I decided to simulate the game monopoly. The rules are the same as the board game, so the idea is that each "property" or board piece is a button. I will have variables for the players position and player totals. To indicate an owned property, I'll change the buttons to flatstyle and use the bordercolor property.
To indicate the player position, I change the text on the button to include "Player: " etc. The trouble I'm having is that each button is named based on position, followed by the name. ie: "btn1Start", "btn2BalticAvenue", so on and so forth. Now, once I roll the two die and gather random integers, I add the total to the player position. Now what I want to do is find the button that the position corresponds to.
Private Sub turn(ByRef playerPosition As Integer)
Dim die1 As Integer = Int(6 * Rnd() + 1)
Dim die2 As Integer = Int(6 * Rnd() + 1)
playerPosition += die1 + die2
Dim button1 As Button = ?
I've tried various methods. Me.Controls.Contains("btn" & Position) is a boolean, so I can't make an object control class equal to that. Me.Controls.Find requires an exact name, so I can't do Me.Controls.Find("btn" & Position) because it needs the full name - each property has something else added on to the name (eg "BalticAvenue"). I want to set the button equal to the specific button based on the turn position, so I can update the text to include the player and allow him/her to initiate the property's effect (buy/pay rent/or chance cards).
I've got a main form (Form1.vb) where I created some controls (with the Designer).I've created a class myTextBox, inheriting from TextBox, in myTextBox.vb.In the main form, I call procedures from myTextBox. The issue is, those procedures use values from the Form controls. So the class doesn't recognise them as initialised.What's the best solution for this?I think I could pass the object itself as a parameter but doing it on each call seems a bitredundant and it thickens the code.Is there any way to access the Form1 controls and objects directly from the myTextBox.vb class?
View 6 RepliesI am getting following error whenever I want to use IIf function inside entity framework query.
LINQ to Entities does not recognize the method 'System.Object IIf(Boolean, System.Object, System.Object)' method, and this method cannot be translated into a store expression.
How can I convert an object of type System.Data.Linq.DataQuery to System.Linq.IQueryable?I'm working with Visual Basic/Silverlight, and the source code of my query is as follows:
Public Function Get_Cli_Pag() As IQueryable(Of V_Cliente_Pagare)
Dim Qry = From P In Me.Context.Pagares Join C In Me.Context.Codigos On C.Codigo
[code]....
I'm trying to convert DataTable to Linq using
DIm result = From r in dt.AsEnumerable()
Select new ( col1 = r.Field<integer>("id"), col2 = r.Field<string>("desc"))
But i get error near 'new (' saying type expected.
I found the following example on [URL] Unfortunately, I need it in VB and it's using some constructs that neither I nor the automated code converters reciognize. Anyone out there know how this should be written in VB.Net? (the problem spot is the "select new {...")
PeopleDataSet ds = new PeopleDataSet();
using (PeopleDataContext context = new PeopleDataContext())
{
[Code].....
I need help converting datatable to xml using Linq. I could do it with hardcoded column names as you can see in my code .. but i need it without hardcoding it ..Example datatable ..My linq query ..
Dim xmlDoc As New XDocument(
From row In dt.AsEnumerable()
From row In dt.AsEnumerable()[code]......
I'm completely dense here, but I'm trying to get some stats from a DataTable. One of the columns in the datatable is called "colour".I need to find out how many of each instance of "colour" are in the datatable.
I'm trying:
Dim q = From p In PGWorkingDataTable _
Group p By p("colour") Into Group _
[code].....
Why does the following code give an error?
[Code]...
If I change the code to remove the second field, as below, then the code does not give an error.
[Code]...
discovered the compact mode of this instructions vs usual code. I found sample code for selecting, etc. from a datatable, transforming a column in a list or array - all operations are "Select"s - readonly.I need to make an simple update on a certain rows (using LINQ) from a DISCONNECTED datatable for which now I'm using this
for each dr as datarow in dtable.Rows
dr("MyField") = 77
next
[code].....
I have two DataTables:
dt1 - personid, name
dt2 - personid
I want to create a third datatable to include records from dt1 when they are NOT in dt2 using LINQ. In this case, I can bind the third datatable to a dropdownlist.
Am new to the concept Linq.I created a var where i joined 3 tables to get the data and then bind it in a datatable and create a csv file. Now i want to use an additioanl table in the same variable to be bind with the datatable but my problem is i cant use join here since i dnt have any common col or primary col in this additional table.How do i add this extra table?
[Code]...
I'm writing a small web app in VB.NET and I would like to do paging for my DataTable in the following function :
Public Shared Function Testing(ByVal KeyWord As String, ByVal CurrentPage As Integer, ByVal PageSize As Integer) As DataTable
Dim db As New BibleDataClassesDataContext
[code].....
Currently, I am using a loop to find the row I want to update.
Public Sub pubsub_SetUserDGVColumnWidth(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewColumnEventArgs)
' update all user settings for the given column
[Code]....