how can i keep my user control ?

Question

Hi everyone 

 

this is my page load code then when i wantto edit my data  

protected void Page_Load(object sender, EventArgs e)
   {
       if (!this.IsPostBack)
       { DataTable dtAttach = Donate.GetMatDonationAttach(SID);
               {
                   if (dtAttach.Rows.Count > 0)
                   {

                       for (int i = 0; i <= dtAttach.Rows.Count - 1; i++)
                       {
                           Control tempControl = this.Page.LoadControl("UC/UC.ascx");
                           ((ASP.sysadmin_credit_donationmaterial_uc_uc_ascx)tempControl).EquipmentName = dtAttach.Rows[i]["ObjName"].ToString();
                           ((ASP.sysadmin_credit_donationmaterial_uc_uc_ascx)tempControl).Quantity = dtAttach.Rows[i]["Quantity"].ToString();
                           ((ASP.sysadmin_credit_donationmaterial_uc_uc_ascx)tempControl).UnitPrice = dtAttach.Rows[i]["UnitPrice"].ToString();
                           attachSID = Convert.ToInt32(dtAttach.Rows[i]["SID1"].ToString());
                           pHolder.Controls.Add(tempControl);
                       }
                   }
               }
   }
}

then add another usercontrol on my page, but loaded data automatically remove on the my page 

 

 

this is my adding user control button  

protected void btnAdd_Click(object sender, EventArgs e)
{
               for (int i = count; i <= _block.Count; i++)
                {
                    if (!this._block[i].Visible)
                    {
                        this._block[i].Visible = true;
                        break;
                    }
                }
}

 how can i resolve when i add new usercontrol then keep old usercontrol and data ??