如何通过BindingNavigator在DataBase中插入，更新和删除DataGridView的记录

Question

I have a Student table and a bunch of other tables in my database called University and I used Entity Framework to connect to it in my winforms application.

I created a DataSource from the Student table inside my Entity Framework model.

then I dragged the DataSource on to my form.(See the pic below)
I know how to populate the records of the student table (here is just one record in my DB) into the DataGridView , with no problem using this piece of code:

//An instance of my EFModel
    Oublic UniversityEntities UE = new UniversityEntities();
 private void Form1_Load_1(object sender, EventArgs e)
    {
        studentBindingSource.DataSource = UE.Students.ToList();
    }

But I want to use BindingNavigator to insert/update/delete records from/to the database and I don't khow how it's possible, considering that I use Entity Framework.

For example,I tried this to save changes after editing a row, but it didn't work:

 private void studentBindingNavigatorSaveItem_Click(object sender, EventArgs e)
    {
        UE.SaveChanges();
    }

Answer 1

I know it's an old thread but I faced the same problem with no answer here.

this line is breaking DataSource's connection to context:

studentBindingSource.DataSource = UE.Students.ToList();

changed it to:

studentBindingSource.DataSource = UE.Students;

but it throws an exception, so I just bind it to local data:

studentBindingSource.DataSource = UE.Students.Local;

Also you need to make sure local data has filled before binding.

Answer 2

Please define "it didn't work". Is the data at least getting pushed to the underlying entity ?

I remember there was some issue with those "light weight" toolbar buttons caused by the fact that they don't cause a loss of focus, thus there's no validation happening on the datagrid.

Just before your call to UE.SaveChanges(), try forcing validation by doing:

this.Validate();

Hope this helps