'System.Data.DataRowView' in DropDownList

Question

I cannot bind data to a Dropdown List.. Can any one explain me why? Error is : 'System.Data.DataRowView' does not contain a property with the name '_DeptID'. my code is:

public class ClassDataManagement
{
    public DataTable BindDropDownList(string Sql, DropDownList DropDownList)
    {
        SqlConnection cn = new SqlConnection(@"Data Source=ABID-PC;Initial Catalog=_uniManagement;Integrated Security=True");
        SqlCommand cmd = new SqlCommand(Sql, cn);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count == 0)
        {

        }
        else
        {
            DropDownList.DataTextField = "Name";
            DropDownList.DataValueField = "_DeptID";
            DropDownList.DataSource = dt.DefaultView;
            DropDownList.DataBind();
        }
        return dt;
    }

}
protected void Page_Load(object sender, EventArgs e)
{
    ClassDataManagement dm = new ClassDataManagement();
    dm.BindDropDownList("select _Program.Name from _program,_Department where _program._Deptid = _department._DeptId", DropDownListProgram);
}

Answer 1

1. The column _Dept is missing in your select statement

2. Disposing of the objects is missing. So you can perform it in two ways

   (a) Manually disposing

   (b) Using Statement

---

public class ClassDataManagement
{
    public DataTable BindDropDownList(string Sql, DropDownList DropDownList)
    {
        using (SqlConnection cn = new SqlConnection(@"Data Source=ABID-PC;Initial Catalog=_uniManagement;Integrated Security=True"))
        {
            using (SqlCommand cmd = new SqlCommand(Sql, cn))
            {
                using(SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    using (DataTable dt = new DataTable())
                    {
                        da.Fill(dt);
                        DropDownList.DataTextField = "Name";
                        DropDownList.DataValueField = "_Deptid";
                        DropDownList.DataSource = dt.DefaultView;
                        DropDownList.DataBind();
                        return dt;
                    }
                }
            }
        }
    }

}
protected void Page_Load(object sender, EventArgs e)
{
    ClassDataManagement dm = new ClassDataManagement();
    dm.BindDropDownList("select _Program.Name, _program._Deptid from _program,_Department "
        + "where _program._Deptid = _department._DeptId", DropDownListProgram);

}

EDIT - 1

Adding the Using Statement for SqlDataAdapter as well