Entity Framework 6 - Knowledge Base (KB)
57 results in tag: winforms
Add an empty item to the combobox associated with the entity list.
I use a ComboBox which is bound to a List<> of Entities. How can I add a "Not selected" entry to the combobox? Adding null to the list results in empty combobox.
asked by wRAR
On a WinForms DataGridView, how do you refresh the DataSource?
I populate the GridView.DataSource from a EntityFramework Model:...gwTimeLog.DataSource = _entities.TimeLogs; ...When a new row is added to the _entities, I try to update the grid (tried using the same statement as above, setting it null, then back to _en...
asked by AngryHacker
LINQ to Entities apps are being deployed.
I want to use L2E since it's very convenient to my company's apps, I created a demo project, the demo does run on every machine but when I, let's say, press a button that has some code that uses the entity I get this error:...specified store provider cann...
asked by Luiscencio
Using Entity Framework to run a custom query
I want to execute custom query to get datetime of DB server ...select Getdate()... using entity framework. How can I do this?...Thanks
asked by Muhammad Akhtar
When DataGridView is attached to a binding source that is linked to an EF4 Entity, how do you sort it?
I have a ...DataGridView... that is linked to a ...BindingSource.......My ...BindingSource... is linked to an ...IQueryable... list of entities:... public void BindTo(IQueryable elements) { BindingSource source = new BindingSource(); ...
asked by Martin
Exception in a Windows form application
I get application exception... at System.Windows.Forms.CurrencyManager.get_Item(Int32 index) at System.Windows.Forms.CurrencyManager.get_Current() at System.Windows.Forms.DataGridView.DataGridViewDataConnection.OnRowEnter(DataGridViewCellEventArgs...
asked by Anton
Linq Query continues to generate errors "A constant variable of type System could not be created. Object ", Why?
The following is the code sample: ...private void loadCustomer(int custIdToQuery) { var dbContext = new SampleDB(); try { var customerContext = from t in dbContext.tblCustomers // keeps throwing: ...
asked by Neel
In a winform application, the lifespan/scope of context in Entity Framework 4
Sorry for yet another question about EF4 context lifespan, but I've been wondering about this for a while and I do not seem to find the answer. I'm not very familiar with lots of patterns or overcomplicated stuff (in my point of view) so I want to keep it...
asked by johnildergleidisson
Using C# to connect Entity Framework objects to a Datagridview
I have been trying to bind an Entity Framework object to a DataGridView but I keep hitting dead ends and I can't seem to find my answer anywhere....I can bind the whole of a table (entity) to a gridview and it will allow me to make changes and save those ...
asked by Jimbo James
utilizing entity framework to obtain a single value
I have a ... table product with colums product_id prodcut_name category_id another table category category_id ...
asked by Enigma State
Using linq-to-entities to convert a string to a datetime has a significant problem.
How can I convert the string to datetime using linq to entities .......I have got the below query, where the ...visit_date... column datatype is string......var memberl = from v in abc.visits join m in abc.members on v.member_Id equals m.mem...
asked by Enigma State
What is the best way to tell whether an Entity Framework object has changed?
I've an object which is called ...Uczestnik... which just got saved to database ...var konsultant = uczestnik.Konsultanci; uczestnik.Konsultanci = null; // null attached object and reuse it's ID later on for SAVE purposes uczestnik.KonsultantNazwa = kons...
asked by MadBoy
Framework for Entities In Windows Forms, how do I link a textbox to a model?
Using Entity data model in a Windows Forms Project, I want to bind simultaneously Orders entity to datagridview and to textBox, and textBox has to display OrderID value depending on the current line in the datagrid....The code I used in Form load event i...
asked by Sami-L
Get Application Path
Ok, I am moving a few of my Winform projects from Framework 4.0 to Framework 4.5 and I am running into a problem trying to find the Executable path from a Class Library. I have an error logging class that I use to log errors here is a snippet of my code:....
asked by Mark Kram
Dependency Injection in WinForms using Ninject and Entity Framework
I am currently working on a project where we are converting our old DataSet, Stored Procedure WinForm application to use Entity Framework so new websites can access the same object model and repositories....Anyway, I am trying to implement Dependency Inje...
asked by XN16
ComboBox DataSource And Entity FrameWork
I add Data Model Entity to my project named ...publishingCompanyEntities... And added ComboBox in my winform. but when i want to bind my list of authors into my combo box as data source has been filled with data , but ...cmoAuthors.Items.Count... returns ...
asked by Moslem .
datagridview binding to entity not updating database
I am populating a grid from a entity object and it is displaying the data fine. When I make changes and save it back, nothing is updating....Here is my code:...In my load event:... var query = from c in _entities.PaymentTypes where c.Corpor...
asked by ErocM
Why is compiler requesting reference to Entity Framework in User Interface project?
I am trying to learn how to create a Winform C# app, that uses EF with repository pattern. ...From my understanding, UI layer should be independent from Entity Framework (it uses data through repository and it shouldn't care if there is an Entity framewor...
asked by Prokurors
Entity Framework does not generates ObservableCollection
Im using EF6 in my dataentry program. EF does not generates ObservableCollection but HashSet and ICollection instead , so i have to change it manually. Unfortunately every time i Update Model from Database , every Many-Many relation goes back to ICollecti...
asked by Theodoros
How to get data from database with Entity Framework?
Using c#, net.4.5 vs 2012...I'm trying to get data from database using Entity Framework....At first idea was use code like below - it's must allow to add, delete and update entries in dataGridView, and than just save changes using ...context.SaveChanges()...
asked by gbk
