Extract the data from a SelectedItem event from a LINQ filled DataGrid

Question

I have a table "Cards" in a database with tables "Cards" and "Customers". Cards contains CustomerID, Number and Ammount. After that, I used ADO.NET to make use of DataGrid, TextBox, etc.

I dropped a DataGrid and a TextBox as a Search Criteria. When a button is pressed, the DataGrid is loaded with the LINQ:

string searchString = this.CustomerIDTextBox.Text();
using (var ctx = new bdCustomerEntities()){
    var result = from t in ctx.Cards
                 join t_customer in ctx.Customer on t.CustomerID equals t_customer.id
                 where t.CustomerID == searchString
                 select new
                 {
                     number = t.number,
                     ammount = t.ammount,
                     CustomerID = t.Customer.id
                 };
    /*Fill datagrid*/
    this.CardsDataGrid.ItemsSource = result.ToList();
}

The problem comes when I made a MouseDoubleClick event in the CardsDataGrid to select the row and fill two TextBoxes, one with the Ammount data and the other one with Number.

I tried this code but it fails to show the data in the TextBoxes:

Cards selected = this.cardsDataGrid.SelectedItem as Cards;
this.numberTextBox.Text = selected.Number.ToString();
this.ammountTextBox.Text = seleccionado.Ammount.ToString();

I made a MessageBox.Show after the Cards selected = ... line to see the content on the SelectedItem, and it shows something like this:

{number = 13, ammount = 3500 , CustomerID = 1456 }

My problem is that, I can't "extract" the SelectedItem because of the format created - maybe by the LINQ? - and put that in the TextBoxes.

Something I noticed, when I made this change to the above code:

Cards selected = (Cards) this.cardsDataGrid.SelectedItem ;

It shows:

System.InvalidCastException:Unable to cast object of type '[System.Int32,System.Int32,System.String]' to type 'bdCustomer.Cards'.

Answer 1

Your LINK is returning an anonymous type not the Cards type, and there is no cast available between the anonymous type and the Cards type, which is what the error is telling you.

Change your LINQ to this:

var result = from t in ctx.Cards
             join t_customer in ctx.Customer on t.CustomerID equals t_customer.id
             where t.CustomerID == searchString
             select t;