c# - Auto-Complete in textbox using data from a SQL Server database -

i trying textbox auto-complete when user types in write query. similar how sql server management studio , gives option type arrow down or click on table name or column name. here following code have.

public void loaddata() {     var myconnection = new sqlconnection(dbconnectionbox.text);     myconnection.open();      autocompletestringcollection namescollection = new autocompletestringcollection();     string query = @"select distinct [name] [information_schema.tables]";      sqlcommand cmd = new sqlcommand(query, myconnection);      sqldatareader dr = cmd.executereader();      if (dr.hasrows == true)     {         while (dr.read())             namescollection.add(dr["name"].tostring());     }      dr.close();     myconnection.close();      manualquerybox.autocompletemode = autocompletemode.append;     manualquerybox.autocompletesource = autocompletesource.customsource;     manualquerybox.autocompletecustomsource = namescollection; }  private void manualquerybox_keyup(object sender, keyeventargs e) {     loaddata(); } 

this code use grab in textbox , execute it.

private void executebtn_click(object sender, eventargs e) {     this.clientinfodgv.datasource = null;     this.clientinfodgv.rows.clear();      var myconnection = new sqlconnection(dbconnectionbox.text);      var manualcmd = new sqlcommand(manualquerybox.text);     manualcmd.connection = myconnection;     manualcmd.commandtype = commandtype.text;      sqldataadapter sqladap = new sqldataadapter(manualcmd);     datatable mqrecord = new datatable();     sqladap.fill(mqrecord);      clientinfodgv.datasource = mqrecord; } 

i have never done autofill before looking around have see asp.net ajax control toolkit, not entirely sure how works. welcome.

update auto-fill code

public void loaddata()         {             var myconnection = new sqlconnection(dbconnectionbox.text);             myconnection.open();             autocompletestringcollection namescollection = new autocompletestringcollection();             string query = @"select distinct [id] [clients]";             sqlcommand cmd = new sqlcommand(query, myconnection);             sqldatareader dr = cmd.executereader();             if (dr.hasrows == true)             {                 while (dr.read())                     namescollection.add(dr["id"].tostring());              }              dr.close();             myconnection.close();              manualquerybox.autocompletemode = autocompletemode.suggestappend;             manualquerybox.autocompletesource = autocompletesource.customsource;             manualquerybox.autocompletecustomsource = namescollection;         } 

try changing autocomplete mode suggestappend:

manualquerybox.autocompletemode=autocompletemode.suggestappend; 

i don't think need load data every time in key event long load once (perhaps in form load) , specify source of text box.

this might help:https://msdn.microsoft.com/en-us/library/system.windows.forms.textbox.autocompletemode(v=vs.110).aspx