asp.net girdview 问题

删除功能一按 就出现：索引超出范围。必须为非负值并小于集合大小。
参数名: index


public partial class _Default : System.Web.UI.Page
{

    public static SqlConnection create()
    {
        SqlConnection con = new SqlConnection("server=.;uid=sa;pwd=4184085dsc;database=data;");
        return con;
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            bind();
       
    }


    public void bind()
    {
        SqlConnection con = create();
        con.Open();
        SqlCommand cmd = new SqlCommand("select * from db", con);
        SqlDataReader sdr = cmd.ExecuteReader();
        gv1.DataSource = sdr;
        gv1.DataBind();
        sdr.Close();
        con.Close();
    }

    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {
      gv1.EditIndex = e.Ne