基本事件定义(观察者模式 Command模式)

import java.awt.*;

import java.awt.event.*;

public class TFActionEvent {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

new TFFrame();

}

}

class TFFrame extends Frame

{

TFFrame()

{

TextField tf = new TextField();

tf.setName("tf");

add(tf,"North");

TextField tf2 = new TextField();

tf2.setName("tf2");

//add(tf2);

add(tf2,"Center");

tf.addActionListener(new TFActionListener());

tf2.addActionListener(new TFActionListener());

pack();

setVisible(true);

}

}

class TFActionListener implements ActionListener

{

public void actionPerformed(ActionEvent e)

{

TextField tf = (TextField)arg0.getSource();

System.out.println(tf.getName()+":"+tf.getText());

//tf.setText("");

}

}

内部类的一个应用

import java.awt.*;import java.awt.event.*;public classTFMath {public static voidmain(String[] args) {newTFFrame().launchFrame();

}

}class TFFrame extendsFrame {

TextField num1, num2, num3;public voidlaunchFrame() {

num1= new TextField(10);

num2= new TextField(10);

num3= new TextField(15);

Label lblPlus= new Label("+");

Button btnEqual= new Button("=");

btnEqual.addActionListener(newMyMonitor());

setLayout(newFlowLayout());

add(num1);

add(lblPlus);

add(num2);

add(btnEqual);

add(num3);

pack();

setVisible(true);

}private class MyMonitor implementsActionListener {public voidactionPerformed(ActionEvent e) {int n1 =Integer.parseInt(num1.getText());int n2 =Integer.parseInt(num2.getText());

num3.setText("" + (n1+n2));

}

}

}//class MyMonitor implements ActionListener {//TextField num1, num2, num3;

/*public MyMonitor(TextField num1, TextField num2, TextField num3) {

this.num1 = num1;

this.num2 = num2;

this.num3 = num3;

}*/

/*TFFrame tf = null;

public MyMonitor(TFFrame tf) {

this.tf = tf;

}

public void actionPerformed(ActionEvent e) {

int n1 = Integer.parseInt(tf.num1.getText());

int n2 = Integer.parseInt(tf.num2.getText());

tf.num3.setText("" + (n1+n2));

}

}*/

优点： 可以方便的访问包装类的成员

可以清楚的组织逻辑，防止不应该被其他类访问的类进行访问

何时使用

该类不允许或不需要其他类进行访问

Java Swing中处理各组件事件的一般步骤是：

1．　新建一个组件(如JButton)。

2．　将该组件添加到相应的面板(如JPanel)。

3．　注册监听器以监听事件源产生的事件(如通过ActionListener来响应用户点击按钮)。

4．　定义处理事件的方法(如在ActionListener中的actionPerformed中定义相应方法)。

3种时间处理机制：

(1)使用内部类

import java.awt.*;import java.awt.event.*;public class TFFrame extendsFrame {

TextField num1,num2,num3;public voidlaunchFrame()

{

num1=new TextField(10);

num2=new TextField(10);

num1.setText("0");

num2.setText("0");

num3=new TextField(15);

num3.setText("0");

Label lblplus=new Label("+");

Button btnEqual=new Button("=");

btnEqual.addActionListener(newmyMontion1(num1,num2,num3));

num2.addActionListener(new myMontion2(this));

num1.addActionListener(newmyMontion());

setLayout(newFlowLayout());

add(num1);

add(lblplus);

add(num2);

add(btnEqual);

add(num3);

pack();

setVisible(true);

addWindowListener(newWindowAdapter() {public voidwindowClosing(WindowEvent e) {

System.exit(-1);

}

});

}public class myMontion implementsActionListener

{

@Overridepublic voidactionPerformed(ActionEvent e)

{int n1=Integer.parseInt(num1.getText());int n2=Integer.parseInt(num2.getText());

num3.setText(""+(n1+n2));

}

}

}

(2)传递窗体 到事件

importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;public class myMontion2 implementsActionListener {

TFFrame tf=null;publicmyMontion2(TFFrame tf)

{this.tf=tf;

}

@Overridepublic voidactionPerformed(ActionEvent e) {//TODO Auto-generated method stub

int n1=Integer.parseInt(tf.num1.getText());int n2=Integer.parseInt(tf.num2.getText());

tf.num3.setText(""+(n1+n2));/*if ((this.tf.num1.getText()!=null) && (this.tf.num2.getText()!=null))

{

int n1=Integer.parseInt(this.tf.num1.getText());

int n2=Integer.parseInt(this.tf.num2.getText());

this.tf.num3.setText(""+(n1+n2));

}*/}

}

(3)传递窗体的组件 到事件

importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;import java.awt.*;public class myMontion1 implementsActionListener {

TextField num1,num2,num3;publicmyMontion1(TextField num1,TextField num2 ,TextField num3)

{this.num1=num1;this.num2=num2;this.num3=num3;

}

@Overridepublic voidactionPerformed(ActionEvent e) {//TODO Auto-generated method stub

int n1=Integer.parseInt(num1.getText());int n2=Integer.parseInt(num2.getText());

num3.setText(""+(n1+n2));/*if ((this.tf.num1.getText()!=null) && (this.tf.num2.getText()!=null))

{

int n1=Integer.parseInt(this.tf.num1.getText());

int n2=Integer.parseInt(this.tf.num2.getText());

this.tf.num3.setText(""+(n1+n2));

}*/}

}

// new TFFrame().launchFrame();