Populate only unique values in dropdown list from ItemDataBound Telerik

Question

I have a RadGrid that I populate from SQL database with shipment info and I am trying to populate a dropdown box with each City that appears on the grid. I haven't been able to figure out how to make sure that the values are unique.

Current code that gets this result:

        protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
    {
        if (e.Item is GridDataItem)
        {
            GridDataItem item = (GridDataItem)e.Item;
            DropDownList1.Items.Add(item["shipCity"].Text);
        }
    }

I have not been able to find anything online and might just be googling the wrong question.

Answer 1

Just add additional check if item like this already exist:

if (e.Item is GridDataItem)
    {
        GridDataItem item = (GridDataItem)e.Item;
        if(DropDownList1.Items.FindByValue(item["shipCity"].Text) == null)
            DropDownList1.Items.Add(item["shipCity"].Text);
    }