1.Swing自定义事件-将一个组件的事件传递给另一个组件.

使用EventListenerList来管理事件,当A组件触发事件的时候,调用方法fireActionPerformed()来触发事件,然后再B组件中 actionPerformed()方法来接收事件.

当在容器KeyTextComponent中按下鼠标,我们就可以在Jframe中捕获触发的事件.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.EventListener;

import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.event.EventListenerList;

class KeyTextComponent extends JComponent {
  private EventListenerList actionListenerList = new EventListenerList();

  public KeyTextComponent() {
    KeyListener internalKeyListener = new KeyAdapter() {
      public void keyPressed(KeyEvent keyEvent) {
        System.out.println("keyPressed");
        if (actionListenerList != null) {
          int keyCode = keyEvent.getKeyCode();
          String keyText = KeyEvent.getKeyText(keyCode);
          ActionEvent actionEvent = new ActionEvent(this, ActionEvent.ACTION_PERFORMED, keyText);
          fireActionPerformed(actionEvent);//触发事件
        }
      }
    };
    MouseListener internalMouseListener = new MouseAdapter() {
      public void mousePressed(MouseEvent mouseEvent) {
        requestFocusInWindow();
      }
    };

    addKeyListener(internalKeyListener);
    addMouseListener(internalMouseListener);
  }

  public void addActionListener(ActionListener actionListener) {//事件管理
    actionListenerList.add(ActionListener.class, actionListener);
  }

  public void removeActionListener(ActionListener actionListener) {
    actionListenerList.remove(ActionListener.class, actionListener);
  }

  protected void fireActionPerformed(ActionEvent actionEvent) {//触发事件
    EventListener listenerList[] = actionListenerList.getListeners(ActionListener.class);
    for (int i = 0, n = listenerList.length; i < n; i++) {
      ((ActionListener) listenerList[i]).actionPerformed(actionEvent);
    }
  }

  public boolean isFocusable() {
    return true;
  }
}

public class KeyTextComponentDemo {
  public static void main(String[] args) {
    JFrame aWindow = new JFrame();
    aWindow.setBounds(30, 30, 300, 300); // Size
    aWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    KeyTextComponent com = new KeyTextComponent();
    aWindow.add(com, "Center");
    com.addActionListener(new ActionListener() {

      public void actionPerformed(ActionEvent e) {
        System.out.println("action");//获取事件

      }

    });

    aWindow.add(new JTextField(), "South");

    aWindow.setVisible(true); // Display the window
  }
}