无法将数据保存到数据库

Question

I have a problem. I can't save the selected data from the combo box into a database. Can anyone provide any opinion or why it's like that?

Here are the codes that enables you all to understand more about my problem:

private void Create_LS_Load(object sender, EventArgs e)
    {
        using (satsEntities Setupctx = new satsEntities())
        {
            cbStation.DisplayMember = "StationName";
            cbStation.ValueMember = "StationID";
            cbStation.DataSource = Setupctx.stations.ToList();

            cbLocation.DisplayMember = "LocationName";
            cbLocation.ValueMember = "LocationID";
            cbLocation.DataSource = Setupctx.locations.ToList();
        }
    }

private void btnCreate_Click(object sender, EventArgs e)
    {
        using (satsEntities Setupctx = new satsEntities())
        {
            locationstation ls = new locationstation();
            ls.stationID = cbStation.SelectedIndex;
            ls.locationID = cbLocation.SelectedIndex;
            Setupctx.locationstations.AddObject(ls);
            Setupctx.SaveChanges();

            cbStation.SelectedIndex = -1;
            cbLocation.SelectedIndex = -1;

            MessageBox.Show("New Location Station Is Created");
        }
    }

Any help will be greatly appreciated. Thanks!

Answer 1

In your create method, why are you assigning SelectedIndex to ls.StationID and ls.locationID ? Selected index will give you the index of the selected item. I believe you are interested in SelectedItem or you may use Text Property.

EDIT:

Since your StationID and locationID are int, you may Convert the SelectedItem to int before assigning them to the fields. ( its better to use int.TryParse to avoid the exception )

int stationID = Convert.ToInt32(cbStation.SelectedItem.ToString());
int locationID = Convert.ToInt32(cbLocation.SelectedItem.ToString());

or

int stationID = Convert.ToInt32(cbStation.Text);
int locationID = Convert.ToInt32(cbLocation.Text);

Then

ls.stationID = stationID;
ls.locationID = locationID;