c# - Adding search function to an invoice application -

i'm new programming , know basic of c#.

i'm doing invoice application in visual studio can store customer name, contact number, address, costs, date of purchase.

i want add search function invoice application retrieve customer there name. these code. please help

namespace invoice_application_final { public partial class main : form {

    public main()     {         initializecomponent();          //listview properties         listview.view = view.details;         listview.fullrowselect = true;           //add column listview         listview.columns.add("customer number", 100);         listview.columns.add("customer name", 150);         listview.columns.add("address", 200);         listview.columns.add("invoice number", 100);         listview.columns.add("contact number ", 100);         listview.columns.add("description", 200);         listview.columns.add("costs", 100);         listview.columns.add("payment date", 100);      }         // insert listview     private void insert(string custnum, string custname, string address, string invoicenum, string contactnum, string description, string costs, string paymentdate)     {          // arrays         string[] row = { custnum, custname, address, invoicenum, contactnum, description, costs, paymentdate };          listviewitem item = new listviewitem(row);          listview.items.add(item);       }          private void update()     {         //update         listview.selecteditems[0].subitems[0].text = txtcustomernumber.text;         listview.selecteditems[0].subitems[1].text = txtcustomername.text;         listview.selecteditems[0].subitems[2].text = txtaddress.text;         listview.selecteditems[0].subitems[3].text = invoicenumbertxt.text;         listview.selecteditems[0].subitems[4].text = contactnumbertxt.text;         listview.selecteditems[0].subitems[5].text = descriptiontxt.text;         listview.selecteditems[0].subitems[6].text = coststxt.text;         listview.selecteditems[0].subitems[7].text = paymentdatetxt.text;          // clear textbox after pressing button         txtcustomernumber.text = "";         txtcustomername.text = "";         txtaddress.text = "";         invoicenumbertxt.text = "";         contactnumbertxt.text = "";         descriptiontxt.text = "";         coststxt.text = "";         paymentdatetxt.text = "";      }       private void delete()     {         if (messagebox.show("are sure?", "warning", messageboxbuttons.yesno, messageboxicon.warning) == dialogresult.yes)         {             listview.items.removeat(listview.selectedindices[0]);         }          // clear textbox after pressing button         txtcustomernumber.text = "";         txtcustomername.text = "";         txtaddress.text = "";         invoicenumbertxt.text = "";         contactnumbertxt.text = "";         descriptiontxt.text = "";         coststxt.text = "";         paymentdatetxt.text = "";     }           private void btninsert_click(object sender, eventargs e)     {         //insert         insert(txtcustomernumber.text, txtcustomername.text, txtaddress.text, invoicenumbertxt.text, contactnumbertxt.text, descriptiontxt.text, coststxt.text, paymentdatetxt.text);          // clear textbox after pressing button         txtcustomernumber.text = "";         txtcustomername.text = "";         txtaddress.text = "";         invoicenumbertxt.text = "";         contactnumbertxt.text = "";         descriptiontxt.text = "";         coststxt.text = "";         paymentdatetxt.text = "";     }          private void main_load(object sender, eventargs e)     {      }        private void btnupdate_click(object sender, eventargs e)     {          update();       }        private void btndelete_click(object sender, eventargs e)     {         delete();     }        private void btnclear_click(object sender, eventargs e)     {         txtcustomernumber.text = "";         txtcustomername.text = "";         txtaddress.text = "";         invoicenumbertxt.text = "";         contactnumbertxt.text = "";         descriptiontxt.text = "";         coststxt.text = "";         paymentdatetxt.text = "";     }         private void listview1_mouseclick(object sender, mouseeventargs e)     {         txtcustomernumber.text = listview.selecteditems[0].subitems[0].text;         txtcustomername.text = listview.selecteditems[0].subitems[1].text;         txtaddress.text = listview.selecteditems[0].subitems[2].text;         invoicenumbertxt.text = listview.selecteditems[0].subitems[3].text;         contactnumbertxt.text = listview.selecteditems[0].subitems[4].text;         descriptiontxt.text = listview.selecteditems[0].subitems[5].text;         coststxt.text = listview.selecteditems[0].subitems[6].text;         paymentdatetxt.text = listview.selecteditems[0].subitems[7].text;        }      private void searchtxt_textchanged(object sender, eventargs e)     {            }   } } 

if it's windows forms project, believe is, use textbox feature called autocomplete mode: autocompletemode

if project uwp you'd use control called autosuggestbox: autosuggestbox

in code-behind put whatever code want in various event handler when enters search term or clicks on suggestion match.