使用LINQ查询填充组合框（不同）

Question

I have a combocox the name is "cmbModel" I want to fill the database with two different values in a table. This is what I have done:

private void Form1_Load(object sender, EventArgs e)
        {
            using (LINQSQLDataContext db = new LINQSQLDataContext())
            {
                cmbModel.DisplayMember = "szModel";
                cmbModel.DataSource = db.VehEcus.ToList<VehEcu>();
            }
        }

this will fill my cmbModel with szModel column of my table but I want to avoid repeating , how can I use " distinct " in query to achieve my goal? and also I want to show 2 items of my table like " modelID-szModel " in my combobox

Thanks

Answer 1

如果您只想显示单个列，则可以选择该列并使用Distinct ：

cmbModel.DataSource = db.InfoProg_VehEcus.Select(x => x.szModel).Distinct();

Answer 2

You can apply Distinct() at any point after your query. I recommend doing it before you enumerate.

To create the custom modelID-szModel field, you can enumerate the query using AsEnumerable(), then create an anonymous type and use String.Format to concatenate your values into your new field.

        using (LINQSQLDataContext c = new LINQSQLDataContext ())
        {
            var items = c.VehEcus.Select(t => new
            {
                a = t.szModel,
                b = t.modelID
            }).Distinct()
            .AsEnumerable().Select(t => new
            {
                displayMember = String.Format("{0}-{1}", t.a, t.b)
            });

            cmbModel.DisplayMember = "displayMember";
            cmbModel.DataSource = items.ToList();
        }