Pagination Not Working On GridView

I have a griview which contains label template field.  The label values are filled during the RowDataBound. When I do pagination except this template field , all  are paginated. I think, when do pagination, each time the label template field are filled on RowDataBound.
Now I am not able to do pagination. Please help
This is my Code
   
               
                   
                       
                           
                               
                                    Text
                               
                           
                       
                       
                       
                       
                       
                       
                       
                       
                       
                       
                   
               
           
 
GridView.cs
protected void Page_Load(object sender, EventArgs e)
        {
            Getdata();
        }
       
        public void Getdata()
        {
            SqlConnection con = new SqlConnection("Data Source=CMH-SOSQL\\SQ1;Initial Catalog=RPT2020_DEV;Integrated Security=True");
            con.Open();
            string qry = "use PID2020_DEV select * from batch_void_rsn_cd";
            SqlDataAdapter da = new SqlDataAdapter(qry, con);
            DataTable dt = new DataTable();
            da.Fill(dt);
            GridView1.DataSource = dt;
            GridView1.DataBind();   
        }
        protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                GridView1.Columns[0].HeaderText = "First Row";
                Label lblKey = (Label)e.Row.FindControl("Label1");
                lblKey.Text = e.Row.RowIndex.ToString();
            }
        }
        protected void GridView1_DataBound(object sender, EventArgs e)
        {
           
        }
        protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            GridView1.PageIndex = e.NewPageIndex;
            Getdata();
        }