Question

My list returns back <string, string> apparently. How can I append the second string in my KeyValuePair and add in the ID that I get back from my second database call?

    // Database calls here

    KeyValuePair<string, string> parks = new KeyValuePair<string, string>();

    DataSet dset = new DataSet();

    var list = new List<KeyValuePair<string, string>>();

    list.Add(new KeyValuePair<string, string>("Select one", "0"));
    foreach (DataRow row in ds.Tables[0].Rows)
    {
        //My database calls including:
         db.AddInParameter(comm, "@pID", DBType.Int32, row[1]);
         dset = db.ExecuteDataSet(comm);
         string attr = dset.Tables[0].Rows[0]["Value"].ToString();
        list.Add(new KeyValuePair<string, string>(row[0].ToString() + " - " + attr, row[1].ToString()));

    }

    return list;

Answer 1

in KeyValuePair<TKey, TValue> key and value are readonly. you can use Dictionary<string,string> for you work and get KeyValuePair<string, string> from it.

I think this works:

// Database calls here
Dictionary<string, string> list = new Dictionary<string, string>();

list.Add("Select one", "0");
foreach (DataRow row in ds.Tables[0].Rows)
{

    list.Add(row[0].ToString(), row[1].ToString());

}

//Another database call that gets back an ID. I want to add/append this ID into my second string in my KeyValue Pair.

return list;

for append the second string you can use list["/*Your ID*/"]= YourData;

List<KeyValuePair<TKey, TValue>> is not good way. It’s like that you use a cup of tea for offing the fire!