Java graphical user interface drop-down list

Java graphical user interface drop-down list

Common methods for drop-down lists:

*jcombobox (): Create a drop-down list with no options

*additem (): Add option

*getselectedindex (): Returns the index of the selected drop-down list option

*getselecteditem (): Returns the selected drop-down list option

*removeitemat (Index): Remove the option to index value to index

*removeallitem (): Remove all options

*additemlistener (): Monitor for registering events

Package Example_java;import Java.awt.flowlayout;import java.awt.event. Actionevent;import java.awt.event. Actionlistener;import java.awt.event. Itemevent;import java.awt.event. Itemlistener;import Javax.naming.initialcontext;import Javax.swing.jbutton;import Javax.swing.JComboBox;import Javax.swing.jframe;import Javax.swing.jscrollpane;import Javax.swing.jtextarea;import Javax.swing.JTextField; ClassWindowchoice extends JFrame implements ItemListener, actionlistener{JComboBox choice; JTextField text; JTextArea area; JButton Add, Del; PublicWindowchoice () {init (); SetSize (400, 400); SetVisible (True); Setdefaultcloseoperation (jframe.exit_on_close);} voidInit () {setlayout (newFlowLayout ()); Choice = newJComboBox (); Text = new JTextField (8); area = new JTextArea (6,25); Choice.additem ("Music World"); Choice.additem ("Martial arts World"); Choice.additem ("Chess Park")); Choice.additem ("Friend Chat"); add = new JButton ("adding"); del = new JButton ("delete" ), Add.addactionlistener (this ), Text.addactionlistener (this ); Del.addactionlistener (this ), Choice.addactionlistener (this ), add (choice), add (Del), add (text), add (add) ; Add (new  JScrollPane (area)), public void  actionperformed (ActionEvent e) {if (e.getsource () = = Add | | e.getsou RCE () = =  text) {String name =  Text.gettext (); if (Name.length () > 0 ) {choice.additem (name); choice.se Tselecteditem (name); Area.append ("\ n List added:" +  name);}} else if (e.getsource () = =  del) {area.append ("\ n list removed:" +  Choice.getselecteditem ()); Choice.remove ( Choice.getselectedindex ()); }} public void  itemstatechanged (itemevent e) {String name =  Choice.getselecteditem (). toString (); int index =< span> Choice.getselectedindex (); Area.settext ("\ n" +index+ ":" +  name);}           

Java graphical user interface drop-down list