I need to use linq in C# Windows form application working with .Net Framework 2 not 3.5 . I Know it may be some sort of stupidity to do that. but i need that for some special reasons. Can i import just linq libraries to my project by anyway ? or there is no way except for using 3.5 ?
View 3 RepliesI have some basic expirience in Visual Basic and programming Windows Forms programs. I know now that forms programs are no longer updated by Microsoft and that WPF is the way to go. No to mention the slicker interface you can create. I've also noticed that passing SQL strings to a database is no longer the standard either. It's either Entity Framwork or Linq.
So I am going for a fresh approach. I need to develop a program that will access a sql database and be accessed by about 10 concurrent users within the office. What's the best approach in general? Linq or Entity Framework? Also, could you recommend a book or two for someone who is new to WPF and Entity Framework? I do have some programming expirience, just none with WPF or the new ways of ADO.net 4.
I'm using Entity Framework in Visual Studio 2010 Beta 2 (.NET framework 4.0 Beta 2). I have created an entity framework .edmx model from my database and I have a handful of many-to-many relationships.
A trivial example of my database schema is
Roles (ID, Name, Active)
Members (ID, DateOfBirth, DateCreated)
RoleMembership(RoleID, MemberID)
[Code]....
For brevity I turned the list of all the columns from the Members table into *
As you can see it's just ignoring the "Role" query.
I am wanting to create a Where statement within my Linq statement, but have hit a bit of a stumbling block.I would like to split a string value, and then search using each array item in the Where clause.In my normal Sql statement I would simply loop through the string array, and build up there Where clause then either pass this to a stored procedure, or just execute the sql string. But am not sure how to do this with Linq to Entity? ( From o In db.TableName Where o.Field LIKE Stringvalue Select o ).ToList()
View 5 RepliesThis is my function:
Public Function GetAllEmployee() As List(Of Employees)
Return DB.Employees.Select(Function(q) New With {q.EmployeeID, q.LastName,q.FirstName}).ToList()
End Function
I'm getting an error:
Value of type System.Collections.Generic.List(Of <anonymous type>) cannot be converted to System.Collections.Generic.List(Of NorthwindModel.Employees).
I'm taking a peek at both the Entity Framework and LINQ to SQL, and while I like the systems (and of course the LINQ integration) I'm a little skeptical on the data-binding aspect. I've taken query results and inspected them, and they don't appear to implement the standard .NET list-binding interfaces (IBindingList, and more importantly ITypedList), leading me to believe that binding them to a grid (or anything else) is going to use reflection to get/set my entity properties. This seems like a comparatively expensive operation, especially when all of the code is generated anyway and could implement the interfaces. Is reflection used to get/set the value of the properties?
Edit: I'm actually concentrating on whether or not ITypedList is implemented somewhere along the way, as that's what has the capability to provide an explicit mechanism for defining and interacting with properties without resorting to reflection. While I didn't have a LINQ to SQL project up,I did inspect a simple Entity Framework entity query result, and it did not appear to implement ITypedList.
Edit 2: After accepting Marc's answer, I thought it might be helpful for others if I posted some simple code I used to seamlessly implement his solution. I put the following in the static constructor for my class:
public static ContextName()
{
foreach(Type type in System.Reflection.Assembly.GetExecutingAssembly()[code]....
While this is for LINQ to SQL, I'm sure an equivalent version could be written for the Entity Framework. This will scan the assembly for any types with the Table attribute and add a custom provider for each of them.
I've seen many examples in LINQ but i'm not able to reproduce the same result in vb.net.
I have following code: Dim context As New MyModel.Entities()
Dim rnd As New System.Random()Dim gardens As List(Of Tuin) = (From t In context.Gardens Where _
t.Approved = True And _
Not t.Famous = True _
Order By rnd.Next() _
Select t).ToList()
[Code]...
I am in the process of developing a messaging framework for a windows application that sends messages to a java application. To be precise when the win app wants to send a message it simply drops the message in a common database table which will be picked up by the java app. The windows application is deployed across 10 application servers (10 instances) over citrix for load balancing.Each instance of the application is capable of sending a message to the java application and each of these messages should have a unique id. From my end I need to make sure every message generated has to carry a unique id so that they can be identified when necessary. All the messages can be cleared every day or two.i am not quite sure about a best method of achieving this. Initially I wanted to create a static method that serves the next available id (incrementing the last id by 1). But this approach willn't guarantee unique number as the application starts only when at least one user is logged on. For e.g .On one server the app starts when a user logs in, he then sends a message and then the application stops when that user logs off. So when a next request for the app comes to that server a new instance will be started.
View 3 RepliesHow can I create a VB application in VS2008 without requiring the application be run on a computer with a .NET framework in place?
View 4 RepliesI imported some code I found a few months ago for a client server messaging program from vs2003 and everything appeared to be ok, apart from a couple of niggles such as the windows form designer generated code being visible on the main form code page but i could live with that. I just tried to add a splash screen but when I went to the application tab to set it up there is no enable application framework checkbox and no windows application framework groupbox. I tried running my application again and now the xp visual style has gone and it looks terrible, is there anyway to get the application framework back on again or do I have to start a new project and copy and past all my code into the new project.
View 1 RepliesI just read this article about the Entity Framework 4 (actually version 2).Entity Framework seems to offer a huge improvement over its first release. Thus, I have never ever used EF in any project, since I think EF is not mature enough in comparison to NHibernate.NHibernate and its current contributions of FluentNHibernate and Linq for NHibernate by Ayende RahienMy feeling is that Microsoft is solely trying to gain terrain it has lost in favor of NHibernate when the 2nd version of NHibernate came out.Nevertheless, my concerns are the followings (not in particular order):Will EF4 tend to be less XML-verbose?Will EF4 be compatible with other underlying datastore than just SQL Server?What are the greatest benefits of going with EF4 instead of FluentNHibernate or NHibernate itself.
NHibernate is a great tool, I guess everyone agrees. Due to its predecessor Hibernate, we may easily find documentions and tutorials and sample applications to get acquainted with it. This is not the case for FluentNHibernate. Particularly as per the project I'm working on right now which demands that I investigate further about NHibernate and its options (FluentNHibernate for instance) in order to document the rules of usage and the best practices of NHibernat and FluentNHibernate technology. Thus, being handcuffed with VB.NET, being a C-Style developer, I can't find some syntax equivalencies in VB.NET for the examples provided, though I made I way so far
I am looking for a VB.net book that strings me through the entire development process of an application (Prefered: WPF ,LINQ ,ADO). I have read a few books on OOP and VB.net with small code samples demonstrating the specific idea of the chapter.I think it would be really helpful if there was a book that programmed an entire application that uses a sql database (Northwind , Adventureworks).
View 1 RepliesI was looking to build a Data Access Layer for my new web based application, I'm using ASP.NET. I'm want to build a framework not only for this application but also want to utilize it for my future projects.
Actually my main aim is to make a framework, from DAC, DAL, BL to GUI. I want suggestions from you guys that what should i adopt, what give me flexibility, which suits for both small and large size applications.
I'm currently using MS Visual Studio 2008 Express Edition. My .NET Framework version is 3.5. I made an application in VS 2008 and it worked perfectly. However, when I ran it at my friend's place (who's got .NET Framework 1.1), it didn't run. Now, I know that the framework incompatibility is the issue.So, what I ask is, how do I code the application so as to make it run on Framework 1.1 as well while still using VS 2008?
View 5 RepliesI have a Windows 7 machine and I see that Microsoft does not recommend Visual Studio 2003 on the computer (Windows 7). How can I develop an application for the .net framework 1.0 then?
View 2 RepliesHow to run a .net 2.0 framework console application in 3.5 framework.
View 1 RepliesThis sounds weird and dumb but supposedly is this possible to run .Net application without installing .net framework? Is there anyway of embedding reference .dlls into the respective application? This came in my mind because I made a small notepad application in vb.net < 1mb in size and to run it, it requires full .net framework.
View 1 RepliesIs it possible to use reflection (or some such thing) to find out if the application framework is enabled? (set in project properties)?
View 3 RepliesI am developing an application using VB.Net which is a simple executable which is to be run from a network drive of our company servers. Most users can access this executable without issue - others however can open the executable but have no connection to our database (even though when running the executable off a local drive such as C:, the database works no problem).
From some posts I have seen this might be a CAS issue - however our IT department suggest the issue might be down to different version of the .NET Framework being to blame. Firstly, is this the issue? Secondly, how can I develop my application to work with different versions of the .NET Framework? Surely this doesn't mean developing many different executables?
The Enable Application Framework Check Box seems pretty well defined in a number oprevious postings, but leaves one question in my mind. The default is unchecked and the sub-topic Check boxes are:
Enable XP Visual Styles - - Checked
Make Single Instance Appllication - - Not Checked
Save My.Settings On Shutdown - -Checked
There are also 3 Combo Boxes:
Authentication Mode - - "Windows"
Shutdown Mode - - "When startup form closes"
Splash Screen - - (None)
When I un check the Enable Application Framework Check Box all items under it are grayed out. However, if I have changed one of the Comb Boxes my selection is also grayed out...My question is, have I lost the use of those function: Specifically I am mos interested in starting my application from a Sub Main and closing the application when all forms close.My underlying question is . . . are the greyed out selections still valid?
I have made a simple vb application and have used vb 2010 to create it, which all of you would know, uses .NET Framework 4.0. I wanted to use this application at work, however, I found out that my work uses .NET framework 3.5 sp1.
So my question is, is there a way to compile something in VB 2010 that will work on .NET 3.5 sp1? If so, how?
For a reason I cannot explain, I now get compiler errors from the Application Designer whenever I enable the application framework in the VB.net IDE. I do not find much on this issue, except Scott Hanselman's admonition not to use this feature. I have mature projects in which this feature was enabled, but now even they will not compile.As this only began a few days ago, I have been trying various approaches to resolving the problem, up to and including removing VS2005 and reinstalling it, along with the framework, SDK, and all updates. No dice. The errors are below.This condition will occur even if I enable the feature in a new project.Does anyone have some thoughts and the cause and resolution of this problem?I probably should mention that I was using both VS2005 and VS2008 on this computer. I had been experimenting with 2008 for several weeks without incident.
[Code]...
If I create an application in VB.NET using Visual Studio 2008, what version of the .NET Framework do other people need to have in order to run my program? Is it the same every time, or does it depend on what the application actually does?
View 1 RepliesFor school i have made an application in VB (Express 2010, .net v4) and when i try to run it at school it says that the .net framework needs to be updated.
IS there anyway of not updating the framework but still allowing the application to run?
I've done a vb.net program. The program basically uses few reference for example system.io etc.In order for my program to run on another computer, the computer need to have .net framework 2.0 installed.Instead of installing the whole framework, can I just pack the references I used in the program together with the vb.net program.? What packager/packer program should I use and how do I go about doing it..?
View 5 RepliesI am facing problems these days. I have VB Express 2008 with 3.5 .Net Frame Work. I develop applications but my applications dont run on the systems those have 2.0 framework or lower.How can I make my applications to run on all kinds of systems
View 2 RepliesMy application seems to require .net framework 4 to run. Hence not working on standard XP installations until .net 4 is installed. How do I make it so that it only needs 3.5, or whatever XP uses natively?
View 5 Replieswitch version is good and can i make it as i will not need installing new netframework and it was in my program like small size?
View 2 Repliesis .NET framework v4 necessary to run my application created by vb2010 to run on other computer??? cause its large file to download....
View 4 RepliesI am in the middle of development of a WPF application that is using Entity Framework (.NET 3.5). It accesses the entities in several places throughout. I am worried about consistency throughout the application in regard to the entities. Should I be instancing separate contexts in my different views, or should I (and is a a good way to do this) instance a single context that can be accessed globally?
For instance, my entity model has three sections, Shipments (with child packages and further child contents), Companies/Contacts (with child addresses and telephones), and disk specs. The Shipments and EditShipment views access the DiskSpecs, and the OptionsView manages the DiskSpecs (Create, Edit, Delete). If I edit a DiskSpec, I have to have something in the ShipmentsView to retrieve the latest specs if I have separate contexts right?
If it is safe to have one overall context from which the rest of the app retrieves it's objects, then I imagine that is the way to go. If so, where would that instance be put? I am using VB.NET, but I can translate from C# pretty good. I just don't want one of those applications where the user has to hit reload a dozen times in different parts of the app to get the new data.
All contexts are created in Using Blocks to dispose of them after they are no longer needed.When loaded, all entities are detatched from context before it is disposed.A new property in the MainViewModel (ContextUpdated) raises an event that all of the other ViewModels subscribe to which runs that ViewModels RefreshEntities method.After implementing this, I started getting errors saying that an entity can only be referenced by one ChangeTracker at a time. Since I could not figure out which context was still referencing the entity (shouldn't be any context right?) I cast the object as IEntityWithChangeTracker, and set SetChangeTracker to nothing (Null).
This has let to the current problem:When I Null the changeTracker on the Entity, and then attach it to a context, it loses it's changed state and does not get updated to the database. However if I do not null the change tracker, I can't attach. I have my own change tracking code, so that is not a problem.
My new question is, how are you supposed to do this. A good example Entity query and entity save code snipped would go a long way, cause I am beating my head in trying to get what I once thought was a simple transaction to work.