更新后，数据网格视图将不会刷新

Question

I am doing simple database client in c#. Right now I'm using entity framework, everything seems to be fine, but after adding a new record to database it won't update. Here's my code :

        private void AddClientConfirmButton_Click(object sender, EventArgs e)
    {
        MainForm frm = new MainForm();
        var newClient = new Klienci
        {
            Imie = FirstNameTextBox.Text,
            Nazwisko = LastNameTextBox.Text,
            Adres = AdressTextBox.Text,
            Telefon = TelephoneTextBox.Text,
            Email = EmailTextBox.Text,
            Status = StatusComboBox.Text
        };
        frm.UpdateDb(newClient);
        Close();
    }

Here's UpdateDb method:

        public void UpdateDb(Klienci newClient)
    {
        var dataContext = new BAKKEntities();
        dataContext.Klienci.Add(newClient);
        dataContext.SaveChanges();
        dataContext.Dispose();
        LoadData();
    }

And there's LoadData:

        public void LoadData()
    {
        var dataContext = new BAKKEntities();
        var clientList = from r in dataContext.Klienci
                         select new
                         {
                             Imie = r.Imie,
                             Nazwisko = r.Nazwisko,
                             Adres = r.Adres,
                             Telefon = r.Telefon,
                             Email = r.Email,
                             Status = r.Status,
                         };
        BindingSource bs = new BindingSource();
        bs.DataSource = clientList.ToList();
        ClientsDataGridView.DataSource = bs;
        dataContext.Dispose();
    }

I have to run my program again if I want to refresh data, and that's not so comfortable

Answer 1

Just set to null and then assign the value,

 BindingSource bs = new BindingSource();
 bs.DataSource = clientList.ToList();
 ClientsDataGridView.DataSource = null;
 ClientsDataGridView.DataSource = bs;
 dataContext.Dispose();

Answer 2

Try this:

bs.ResetBindings(false);
ClientsDataGridView.DataSource = typeof(List); 
ClientsDataGridView.DataSource = bs;

Answer 3

To use ToBindingList() like Noceo said, you have to import System.Data.Entity. do something like :

DataContext.Klienci.Load()

For loading all the clients, and :

bs.Datasource = DataContext.Klienci.Local.ToBindingList()

To link to your data binding. After that, it will updated.

Answer 4

Instead of assigning a List<T> to your BindingSource.DataSource , assign a BindingList to it.

You don't have to create a new BindingSource every time you want to update the collection of Klienci for you DataGridView . Do this only once during initialization and assign the BindingList<T> to the BindingSource.DataSource

The following is only done during initialization (InitializeComponent()?)

DataGridView myDataGridView = new DataGridView();
BindingSouce myBindingSource = new BindingSource();
myDataGridView.DataSource = myBindingSource();

Whenever you need to re-fill your DataGridView with all your Klienci:

using (var dataContext = new BAKKEntities())
{
    IEnumerable<Klienci> clients = dataContext.Klienci
        .Select(client => new Klienci()
        {
            Imie = client.Imie,
            Nazwisko = client.Nazwisko,
            Adres = client.Adres,
            Telefon = client.Telefon,
            Email = client.Email,
            Status = client.Status,
         });
     myBindingsource.DataSource = new BindingList<Klienci>(clients.ToList())
}

Sorry I use linq method-syntax, I'm more familiar with that. The main importance is that you convert your retrieved sequence of Klienci into a BindingList and then assign that to the BindingSource that is already connected to the DataGridView.DataSource.

You might find the following useful Stackoverflow: List vs BindingList Advantages/DisAdvantages

Did you notice I used a using statement. This is to make sure your DataContext is disposed, even if you have an exception.

By the way: if you want your datagridview to be sortable, consider using a SortableBindingList . Usage is the same as a BindingList, except that you