I have an interface 'ICRUDable' and a class called ClientAddress which implements the ICRUDable interface.
My understanding of OOP would lead me to believe that if I declare a System.Data.Linq.Table(Of ICRUDable) then I should be able to put ClientAddress's in there.
The code I have tried includes;
Dim dc As New CRMDataContext
Dim items = dc.ClientAddresses
and
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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
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The problem is, I've never created a class before, not in VB, Java, or anything. I know all the terms associated with classes, I understand at a high level how classes work no problem. But I suck at the actual details of making one.[code]...
As for the Getter and Setter, the reason I put the question marks in is because I want to return the whole array there. The class will eventually have other properties which are basically permutations of the same data, but this is the full set that I will use when I want to save it out or something. Now I want to return the whole Array, but typing "Return fullDataSet()" doesn't seem like a good idea. I mean, the name of the property is "fullDataSet()." It will just make some kind of loop. But there is no other data to return.
I am trying to create a class in VB.NET which inherits a base abstract class and also implements an interface. The interface declares a string property called Description. The base class contains a string property called Description. The main class inherits the base class and implements the interface. The existence of the Description property in the base class fulfills the interface requirements. This works fine in C# but causes issues in VB.NET.
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I've got a web user control (.ascx) which implements a couple of interfaces I wrote; namely IXMLBoundControl and ISectionOverridingControl.I've written a mini-CMS type application that dynamically loads controls onto the page based on information in a database. When I click a button on a web page (.aspx), I want to look at all the controls on that page, and determine if there is a control which implements the ISectionOverridingControl.
I've got my loop and I'm looping through the controls; that's fine. However I'm not sure what the best way is to determine whether or not the control implements the interface. What I'm doing at the moment (and works) is to try to cast each control into the ISectionOverridingControl and catching InvalidCastException: If I don't get the catch; I consider it's worked. If the exception is thrown then it doesn't implement the interface.
It's working, however, I consider this inefficient (relying on exceptions): surely there's a better way in VB.NET (I've seen an example in C# but it didn't convert to VB) to tell whether an instance of a class implements an interface or not?
I recently downloaded VB2008 express. Iam trying to create a link to an SQL table, but the LINQ to SQL class is missing in my add new item menu. is there another way to grab data from a database without using the LINQ to SQL?
View 1 RepliesI have been requested to implement a login form into a friend's Visual Basic .NET application. He specifically requested that I should do this using LINQ to compare the input to a table in an Access database. I don't really know why he imposed these restrictions, but who am I to judge? However, the problem is I am not overly familiar with VB .NET, or LINQ.
View 1 RepliesWhen I write the following statement in VB.Net (C# is my normal language), I get an "end of statement expected" referring to the "Implements" statement.
<Serializable()> _
<XmlSchemaProvider("EtgSchema")> _
Public Class SerializeableEntity(Of T As {Class, ISerializable, New}) _
Implements IXmlSerializable, ISerializable
...
End Class
The C# version that I'm trying to emulate is:
[Serializable]
[XmlSchemaProvider("MySchema")]
public class SerializableEntity<T> : IXmlSerializable, ISerializable where T : class, new()
{
....
}
I'm not sure that I'm doing the right thing here..I'm writing a user control that's supposed to be (fairly) generic. It's a bit like a modified email client specifically tailored to some of the internal things we do.
The view is composed of two main pieces, a message list and a viewer. I need this viewer to be interchangeable, so if someone wants a different style of view they can simply handle an event and change a property. My original idea was to just have an INoteViewer, but since I'm adding it to my form I also need to guarantee that this object is a Windows.Forms.Control of some sort.
Should I continue along these lines and maybe raise an ArgumentException if I can't cast it to INoteViewer, or should I go a different direction and create a class that inherits from Windows.Forms.Control?
I have a datagridview which is bound to a local databse table through a Linq to SQL class.
Everything works as I would expect, when the application runs, up to a point.
If, in the datagridview tasks pane I enable Adding, Editing and Deleting all work as expected.
If I disable Adding & Deleting, leaving Editing enabled, Editing works as expected.
If I disable Deleting & Editing, but leave Adding enabled, Adding does not work, despite the row for new records being displayed. I can move around the row but not enter data.
I suspect somehow its the datasource as opposed to the datagridview that is the cause of my problem but as I say, I can add rows if the Enable Editing option is selected.
Changing the relevant properties programatically makes no difference.
I've been searching for the reason for a couple of days without success.
I have a workaround, by leaving Enable Editing set and programatically setting each row during the RowPostPaint event to be readonly except the row for new records. I would just like to understand what is going on.
I'm working on a form that has a few data grid views that are populated from LINQ queries, no problem there it works as it should however that sorting does not work. After doing some reading its because LINQ results do not support sorting.As I have the LINQ results already is there a way of copying the results into a dataset or datatable then binding the data grid view to that so sorting will work?
View 4 RepliesI cannot get the following to work for me: its the section that sets the default for system.data.linq.binary. The database I work with doesn't allow nulls in any field. So I generally run my buffer through this routine to populate defaults and then set the real values independently, (this works when I miss a field). I can set the Linq table field = fakeBinary and it works like a charm. Thus, I don't understand why using reflection can't pull of the same thing.
Ex: Me.CM20500WindowBuffer.Reconcile_Messages = New Byte() {0} works.
Try
Dim fakeBinary As System.Byte() = {0}
For Each fld In nObj.GetType().GetProperties
Select Case fld.PropertyType
Case GetType(Byte)
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I am using window programming in visual studio(2008) and i am using LINQ and need to get the data from three table's column e.g A table's 1st column(x),b table's 2nd column(y) and c's table third column(z), and then i have to produce the excel sheet(CSV file).I want to get the table's data in string format in visual studio and then produce the excel sheet.I don't want to use Store procedure and grid view in my program.
View 5 RepliesIf I'm extending OnCreated for a LINQ to SQL table object, is it possible to get a reference to the data context to which the table belongs? For example, if I add a property to the data context:
Partial Class MyDataContext
Private _myValue As String
Public ReadOnly Property MyValue As String
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I don't want the property on the data context to be Shared, because it could be different per instance. I've been pouring over the designer code to figure out where the reference might be, but no luck yet.
I have three tables: BOOKS(BookID, Title, Author) CLASSES(ClassID, Title, MajorID,BookID) and MAJORS(MajorID, Description). I added these three tables to a LINQ to SQL class (UBooks.dbml) and then connected to the data sources. Then declared DataContext.
Using LINQ, my goal is to display all books in a grid which I have done with:
Dim allBooks = From Books In db.Books _
Order By Books.BookID _
Select Books
Me.BookBindingSource.DataSource = allBooks
Next I need to display all majors in a listbox. I would like the description to be shown however I am only getting the majorID to display with the code
lstMajors.DataSource = db.Majors
I have tried db.Majors.Description, however I am told then that Description is not a member of the LINQ table. and my final goal is to display all the books for whichever Major is selected in another data grid. This is what I am primarily concerned with right now. When using the SQLClient classes, I was able to create a string joining the tables (also had the description properly showing in the listbox, but that is of little importance right now to me). In the video tutorials I was able to watch whenever the tables were dragged from the database into the OR designer of the LINQtoSQL.dbml class file all of the associations were already there and the narrator only really had to do some drag and drop. Not only is drag and drop not working without these associations, but I'd much rather learn the code behind it.
How do I get a datatable that has been populated(filled) in a subroutine in one class and use it in a sub-routing in another class with that same data?
View 1 RepliesIn a number of my projects, I find myself declaring a rather boring class:
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to e.g. allow an object to give information to another object in such a way that the information can be mutated later wherever it goes. For example, in a Dictionary(Of String, Holder(Of SomeImmutableType)) it's possible to update the thing of SomeImmutableType without having to change the Dictionary itself (since the Dictionary's entry for a given key will always contain the same Holder object, that Holder object may be used as a lock).
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If a class is serialized and has events fired from it that are handled on a form you get the error "Form1 cannot be serialized" in c# you can use (to work around this):
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I have a program that simply checks if the account number and pass word match. And if not it allows you to create it. But i have no idea on how to create something that will hold the data and will allow the user to add and remove sets of data.
View 1 RepliesI have written some functions that I have in a module. In one of the functions I would like to update a table that is in a dataset. I would like to do this with this function and not from a form class where the table could be bound. I need to call the function from various places in the application.
View 3 Repliesi have a table in sql server with some fields set as Byte() (System.Byte[]) when i import them in my application to be used with linq they are converted in Binary (System.Data.Linq.Binary)why is that?is there a way to prevent this wrong translaton???if i update the database how can i update the classes that has been craeted in visual studio2008?
View 2 RepliesI need to grab some data from a webpage but for me the main problem is I can't grab the data the way I want. I want to grab the data in a listview control but my code is fetching all data within any span tag (span class "inputFieldLabel" which is not required) in a single column of a listview control. I am giving the format (source) of the webpage below and my coding in vb.net (2008),
<br>
<span class="inputFieldLabel">Following Are ...</span>
<span class="inputFieldLabel">01/02/2011</span>
<span class="inputFieldLabel">And</span>
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I would use the System.Linq.Dynamic. I added the specified Dynamic.vb file, that starts like this:
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to my (VB.NET)solution. Now Visual Studio does not recognize anymore in the project files the System.XXX references, proposing me to change them to Global.System.XXX
I have two tables Employees and CafeLogs. Some employees can be cashiers and also customers at the Cafe shop.
Table structures:
Employees: EmployeeId(PK) , FirstName, LastName
CafeLogs: LogId (PK), CashierId, EmployeeId, Value, => CashierId and EmployeeId are the data from column EmployeeId of Empoyee table
Table relationship:
Employees 1:N CafeLogs (CashierId (FK))
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Right now I know how to select only LogId, Employee's name, and , Value, not with Cashier name yet.
Dim query = From log In db.CafeLogs _
Join emp In db.Employees On emp.EmployeeId Equals log.EmployeeId _
Select log.LogId, emp.FirsName, emp.LastName, log.Value
I have a bit of a problem. I am using an Access database to hold data for my VB app. In the VB app, I have a data source thats pulling data from the database.
I modified the database today, deleted some tables, added another one, but the data source in the project window does not show these updated changes. I had to reconfigure the datasource with the wizard to get the changes to update.
Is there a way that i can get the data source to update itself when the form loads?
I'm not sure if this is a simple problem or not but it's frustrating me to no end.
I'm using the following code to add my data to the database, and then this to refresh. [code]...
I want to store the contents of an XMl file into an array but struggling to work this out. I have managed to read the data in and store in labels as a test. I then created an array list and used a message box to display the data to see that it has been stored. It does but I am not sure how to group this data. There are 3 records in the file. the idea is to end up with the following:
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Is it possible to use ACCESS DB (MDB) on a SERVER. I would like to use the MDB file to hold my DATA. Has any1 used a multi user vb.net program with Access DB residing on a SERVER? I am just trying out something and do not want to use SQL SERVER for this project.
View 10 RepliesWhen I do this
Public Class cInherits : Inherits Panel
I get this: Base class 'System.Windows.Forms.Panel' specified for class 'MenuButton' cannot be different from the base class 'System.Windows.Forms.UserControl' of one of its other partial types.
How do I inherit?
I´m gettin the error Calling the fuction GetListItems but is kind weird because it works in Visual Studio 2008 Express but no in Visual Basic 2010 Express:
Dim ndQuery As XmlNode = xmlDoc.CreateNode(XmlNodeType.Element, "Query", "")
Dim ndViewFields As XmlNode = xmlDoc.CreateNode(XmlNodeType.Element, "ViewFields", "")
Dim ndQueryOptions As XmlNode = xmlDoc.CreateNode(XmlNodeType.Element,
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