c# - ComboBox don't update -

i got combobox in form1 gets value database

form1 code:

public void fillcombobox() {                using (sqlconnection mydatabaseconnection = new sqlconnection(myconnectionstring.connectionstring))     {          mydatabaseconnection.open();          using (sqlcommand mysqlcommand = new sqlcommand("select lastname, firstname, middlename emp", mydatabaseconnection))          using (sqldatareader sqlreader = mysqlcommand.executereader())          {              while (sqlreader.read())              {                  string lname = sqlreader.getstring(sqlreader.getordinal("lastname"));                  string fname = sqlreader.getstring(sqlreader.getordinal("firstname"));                  string mname = sqlreader.getstring(sqlreader.getordinal("middlename"));                  string fullname = lname + ", " + fname + " " + mname;                   combobox3.items.add(fullname);              }          }     } } 

from form1 have button opens form2 add data in database.

form2 code:

public void adddata() {     string = "insert emp(lastname, firstname, middlename) values('"+textbox1.text+"', '"+textbox2.text+"', '"+textbox3.text+"')";      using (sqlconnection mydatabaseconnection1 = new sqlconnection(myconnectionstring.connectionstring))     {          mydatabaseconnection1.open();          using (sqlcommand mysqlcommand = new sqlcommand(" " + + " ", mydatabaseconnection1))          mysqlcommand.executereader();     }   }  private void button1_click(object sender, eventargs e) {     adddata();     form1 nf = new form1();     nf.fillcombobox();     this.close } 

i check database , verified data added.
problem when add data in datatabase combobox don't update data loads. updates after run program again.

with code:

form1 nf = new form1(); nf.fillcombobox(); 

you creating new form1 after db update (and not showing it). not refreshing original form1.

to see this, add: nf.show(); after fillcombobox() call.

you have refresh original form1 after closing form2.

example:

if(form2.showdialog() == dialogresult.ok)     fillcombobox(); 

and in fillcombobox, should clear combobox3.items before adding new entries.