Как удалить файл excel из папки fileupload после завершения действия в MVC

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у меня есть проблема, когда я загружаю новый файл excel, потому что я не могу удалить файл после завершения действия.

как я его удаляю ?

это мой код :-

[HttpPost]
        public ActionResult Import(HttpPostedFileBase FileUpload)
        {
            bool fileChoosed = false;
            DataSet ds = new DataSet();
            if (FileUpload != null)
            {
                if (FileUpload.ContentType == "application/vnd.ms-excel" || FileUpload.ContentType == "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
                {
                    string filename = FileUpload.FileName;
                    string targetpath = Server.MapPath("~/fileUpload/");

                    FileUpload.SaveAs(targetpath + filename);
                    
                    string pathToExcelFile = targetpath + filename;
                    var connectionString = "";
                    if (filename.EndsWith(".xls"))
                    {
                        connectionString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0; data source={0}; Extended Properties=Excel 8.0;", pathToExcelFile);
                    }
                    else if (filename.EndsWith(".xlsx"))
                    {
                        connectionString = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=\"Excel 12.0 Xml;HDR=YES;IMEX=1\";", pathToExcelFile);
                    }

                    OleDbConnection excelConnection = new OleDbConnection(connectionString);
                    excelConnection.Open();
                    DataTable dt = new DataTable();

                    dt = excelConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                    if (dt == null)
                    {
                        return null;
                    }

                    String[] excelSheets = new String[dt.Rows.Count];
                    int t = 0;
                    //excel data saves in temp file here.
                    foreach (DataRow row in dt.Rows)
                    {
                        excelSheets[t] = row["TABLE_NAME"].ToString();
                        t++;
                    }
                    OleDbConnection excelConnection1 = new OleDbConnection(connectionString);


                    string query = string.Format("Select * from[{0}]", excelSheets[0]);
                    using (OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, excelConnection1))
                    {
                        dataAdapter.Fill(ds);
                    }
                }

                for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                {
                    string conn = ConfigurationManager.ConnectionStrings["WWMCONNDB"].ConnectionString;
                    SqlConnection con = new SqlConnection(conn);
                    // //if customer code found
                    string s1 = @"SELECT COUNT(*) FROM DATA_CUSTOMERS WHERE customer_id = @customer_id";
                    SqlCommand sCommand = new SqlCommand(s1, con);
                    sCommand.Parameters.AddWithValue("@customer_id", ds.Tables[0].Rows[i][11]);
                    con.Open();
                    int records = (int)sCommand.ExecuteScalar();
                    con.Close();
                    if (records == 0)
                    {
                        string s2 = @"SELECT COUNT(*) FROM DATA_NOTIFICATIONS WHERE notification_id = @notification_id";
                        SqlCommand sCommand2 = new SqlCommand(s2, con);
                        sCommand2.Parameters.AddWithValue("@notification_id", ds.Tables[0].Rows[i][1].ToString());
                        con.Open();
                        int records2 = (int)sCommand.ExecuteScalar();
                        con.Close();
                        if (records2 == 0)
                        {
                            string query = "Insert into DATA_CUSTOMERS(customer_id,customer_name,region_id,city_name,address,tele1,tele2) Values('" +
                            ds.Tables[0].Rows[i][11] + "','" + ds.Tables[0].Rows[i][6].ToString() +
                            "','" + ds.Tables[0].Rows[i][3] + "', '" +
                            ds.Tables[0].Rows[i][4].ToString() + "','" +
                            ds.Tables[0].Rows[i][5].ToString() + "','" +
                            ds.Tables[0].Rows[i][7].ToString() + "','" +
                            ds.Tables[0].Rows[i][8].ToString() + "'); insert into DATA_NOTIFICATIONS(notification_id,notificationtype_id,customer_id,problem_desc) Values('" +
                            ds.Tables[0].Rows[i][1].ToString() + "','" + ds.Tables[0].Rows[i][0] + "','" +
                            ds.Tables[0].Rows[i][11] + "','" +
                            ds.Tables[0].Rows[i][10].ToString() + "');";
                            con.Open();
                            SqlCommand cmd = new SqlCommand(query, con);
                            cmd.ExecuteNonQuery();
                            con.Close();
                            fileChoosed = true;

                        }
                    }
                }

            }


            return View(fileChoosed);
        }
    }

Что я уже пробовал:

Как удалить файл excel из папки

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