keyeventdemo.java

JAVA学习源代码,大家可以好好参考,请多提宝贵意见

//KeyEventDemo.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class KeyEventDemo
    extends JFrame
    implements KeyListener{
  private JTextField txtField = new JTextField("  请执行键盘操作  ",20);
  private JTextArea txtArea = new JTextArea(5, 20);
  private String line1 = "", line2 = "", line3 = "";
  public KeyEventDemo(){
    super("Key Event Test");
    Container container = getContentPane();
    container.setLayout(new FlowLayout());
    txtField.setEnabled(false);
    container.add(txtField, BorderLayout.NORTH);
    addKeyListener(this);
    txtArea.setEnabled(false);
    container.add(new JScrollPane(txtArea), BorderLayout.CENTER);
    pack();
    setVisible(true);
  }

  public Dimension getPreferredSize() {
    return new Dimension(600, 200);
  }

  public void keyTyped(KeyEvent e){
    line1 = "Key typed: " + e.getKeyChar();
    outputToArea(e);
  }

  public void keyPressed(KeyEvent e){
    line1 = "Key pressed: " + e.getKeyText(e.getKeyCode());
    outputToArea(e);
  }

  public void keyReleased(KeyEvent e){
    line1 = "Key released: " + e.getKeyText(e.getKeyCode());
    outputToArea(e);
  }

  public void outputToArea(KeyEvent event){
    line2 = "This key is " + (event.isActionKey() ? "" : "not") + " an action key";
    String str = event.getKeyModifiersText(event.getModifiers());
    line3 = "Modifer key pressed: " + (str.equals("") ? "none" : str);
    txtArea.setText(line1 + "\n" + line2 + "\n" + line3);
  }
  public static void main(String args[]){
    KeyEventDemo keyEventDemo = new KeyEventDemo();
    keyEventDemo.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}