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Question

I'm trying to update a label when the combo box selection is changed so that it presents a count from a query. Unless I specify suing a string the where clause, it wont let me use the value from the combobox.SelectedValue, it returns a zero.

where (o.ShipCountry == "USA")

And what I've been trying:

private void cmbCountry_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        var ord = (from o in db.Orders
                   where (o.ShipCountry == cmbCountry.SelectedValuePath)
                   select o.ShipCountry).Count();

        lblOrders.Content = ord;
    }

Here's a screen of the issue to help. The zero should be a count of all the orders to a certain country specified by the combo box.

Any help is much appreciated!

Answer 1

I actually realized my problem! The LINQ query I used to populate the ComboBox used an anonymous type to reference the column being selected. I named it "cc".

var cmb = (from c in db.Customers
                   orderby c.Country descending
                   select new { cc = c.Country }).Distinct();

Which meant the binding path was Binding Path=SelectedValue.cc

var cmb = (from c in db.Customers
               orderby c.Country descending
               select c.Country).Distinct();

By removing the anonymous type I was able to access the SelectedValue of the combobox.