interfaces java awt event Event Handling Listener import

Συνήθη interfaces του πακέτου java. awt. event

Παράδειγμα Event Handling με Listener import java. awt. event. Action. Event; import java. awt. event. Action. Listener; import javax. swing. *; public class Handle. Event extends JFrame { public Handle. Event() { JButton jbt. OK = new JButton("OK"); add(jbt. OK); OKListener. Class listener 1 = new OKListener. Class(); jbt. OK. add. Action. Listener(listener 1); } public static void main(String[] args) { JFrame frame = new Handle. Event(); frame. set. Title("Handle Event"); frame. set. Size(200, 150); frame. set. Default. Close. Operation(JFrame. EXIT_ON_CLOSE); frame. set. Visible(true); } } class OKListener. Class implements Action. Listener{ public void action. Performed(Action. Event e) { System. out. println("OK button clicked"); } } Output: OK button clicked

Παράδειγμα Action. Listener import javax. swing. *; import java. awt. event. *; public static void main(String[] args) { new Action 1(). set. Visible(true); } public class Action 1 extends JFrame implements Action. Listener { public Action 1() { init. My. Components(); set. Default. Close. Operation(JFrame. EXIT_ON_CLOSE); } private void init. My. Components() { j. Panel 1 = new JPanel(); j. Button 1 = new JButton("b 1"); j. Button 1. add. Action. Listener((Action. Listener) this); j. Button 2 = new JButton("b 2"); j. Button 2. add. Action. Listener((Action. Listener) this); j. Button 3 = new JButton("b 3"); j. Button 3. add. Action. Listener((Action. Listener) this); j. Panel 1. add(j. Button 1); j. Panel 1. add(j. Button 2); j. Panel 1. add(j. Button 3); add(j. Panel 1); pack(); } @Override public void action. Performed(Action. Event e) { if (e. get. Source() == j. Button 1) { System. out. println("pressed B 1!"); } else if (e. get. Source() == j. Button 2) { System. out. println("pressed B 2!"); } else if (e. get. Source() == j. Button 3) { System. out. println("pressed B 3!"); } } private JButton j. Button 1, j. Button 2, j. Button 3; private JPanel j. Panel 1; } Output: pressed B 1! pressed B 2! pressed B 3! pressed B 2! pressed B 1!

Παράδειγμα Mouse. Listener import java. awt. *; import java. awt. event. *; import javax. swing. JFrame; public class Mouse. Listener. Example extends JFrame implements Mouse. Listener{ Label l; Mouse. Listener. Example(){ add. Mouse. Listener(this); l = new Label(); l. set. Bounds(20, 50, 100, 20); add(l); set. Size(300, 300); this. set. Default. Close. Operation(JFrame. EXIT_ON_CLOSE); set. Layout(null); set. Visible(true); } public void mouse. Clicked(Mouse. Event e) { l. set. Text("Mouse Clicked"); } public void mouse. Entered(Mouse. Event e) { l. set. Text("Mouse Entered"); } public void mouse. Exited(Mouse. Event e) { l. set. Text("Mouse Exited"); } public void mouse. Pressed(Mouse. Event e) { l. set. Text("Mouse Pressed"); } public void mouse. Released(Mouse. Event e) { l. set. Text("Mouse Released"); } public static void main(String[] args) { new Mouse. Listener. Example(); } }

Παράδειγμα φόρμας εγγραφής φοιτητών (2) package lab 10; import java. awt. *; import javax. swing. *; import java. awt. event. Action. Event; import java. awt. event. Action. Listener; import java. io. Buffered. Reader; import java. io. File. Not. Found. Exception; import java. io. File. Reader; import java. io. File. Writer; import java. io. IOException; import java. util. Array. List; /** * * @author fanis */ public class My. Frame extends JFrame{ private String name; private String lastname; private String am; private JLabel label 1, label 2, label 3; private JText. Field text. Name, text. Lastname, text. Am; private JButton clear, add, read; Array. List<String> students = new Array. List<String>(); public My. Frame(){ this. set. Title("Add Student"); this. set. Layout(new Border. Layout()); JPanel p = new JPanel(); p. set. Layout(new Grid. Layout(4, 3, 5, 5)); label 1 = new JLabel("Name", Swing. Constants. CENTER); p. add(label 1); p. add(new JLabel("")); text. Name = new JText. Field(); p. add(text. Name); label 2 = new JLabel("Last. Name", Swing. Constants. CENTER); p. add(label 2); p. add(new JLabel("")); text. Lastname = new JText. Field(); p. add(text. Lastname); label 3 = new JLabel("AM", Swing. Constants. CENTER); p. add(label 3); p. add(new JLabel("")); text. Am = new JText. Field(); p. add(text. Am); clear = new JButton("Clear"); clear. add. Action. Listener(new Action. Listener() { @Override public void action. Performed(Action. Event e) { text. Name. set. Text(null); text. Lastname. set. Text(null); text. Am. set. Text(null); } }); p. add(clear);

Παράδειγμα φόρμας εγγραφής φοιτητών (3) add = new JButton ("Add"); p. add(add); add. Action. Listener(new Action. Listener() { @Override public void action. Performed(Action. Event e){ String. Builder buff = new String. Builder(text. Name. get. Text()+" "); buff. append(text. Lastname. get. Text()+" "); buff. append(text. Am. get. Text()); students. add(buff. to. String()); try { File f = new File("new. File. txt"); File. Writer writer = new File. Writer(f); for(String student: students) { writer. write(student); writer. write(System. line. Separator()); } writer. close(); JOption. Pane. show. Message. Dialog(null, "Η εγγραφή ολοκληρώθηκε!"); } catch(IOException en) { en. print. Stack. Trace(); } } }); read = new JButton("Read"); read. add. Action. Listener(new Action. Listener() { @Override public void action. Performed(Action. Event e) { try { Buffered. Reader reader = new Buffered. Reader(new File. Reader("new. File. txt")); String line = reader. read. Line(); while(line != null) { System. out. println(line); line = reader. read. Line(); } reader. close(); } catch (File. Not. Found. Exception exc) { exc. print. Stack. Trace(); } catch(IOException exc) { exc. print. Stack. Trace(); } } }); p. add(read); pack(); this. add(p, Border. Layout. CENTER); this. add(new JPanel(), Border. Layout. SOUTH); this. set. Default. Close. Operation(JFrame. EXIT_ON_CLOSE); this. set. Visible(true); } public static void main(String[] args) { My. Frame f = new My. Frame(); f. set. Visible(true); f. set. Size(300, 300); } }