Question

I am trying to use generic for the first time and trying to typecast my result returned from database to programmer defined data type. How can I do this.

dsb.ExecuteQuery("DELETE FROM CurrencyMaster WHERE CurrencyMasterId="
        + returnValueFromGrid<int>(getSelectedRowIndex(), "CurrencyMasterId"));

private T returnValueFromGrid<T>(int RowNo, string ColName)
{
    return Convert.ChangeType(dgvCurrencyMaster.Rows[RowNo].Cells[ColName].Value, T);
}

Answer 1

You’re trying to use T as a value – you want the type T represents, and then you’ll need a cast as well:

object value = dgvCurrencyMaster.Rows[RowNo].Cells[ColName].Value;
return (T) Convert.ChangeType(value, typeof(T));