AWT事件处理

Java AWT事件处理1 AWT事件处理基本概念AWT事件处理的过程中，主要涉及3类对象。

(1) Event（事件）：用户对组件的一个操作，称之为一个事件，以类的形式出现，例如，键盘操作对应的事件类是KeyEvent。

其实例在改事件发生时有系统自动产生。

(2) Event Source（事件源）：事件发生的场所，通常就是各个组件，例如按钮Button。

(3) Event Monitor（事件监听器）：接收事件对象并对其进行处理的类的对象，通常其中某个成员方法对事件进行相应的处理。

事件委托处理模型图10-10 事件委托处理模型Java采取了事件委托处理模型（Delegation Model），事件源自己不处理事件，而是把在其自身所有可能发生的事件委托给事件监听器来处理。

比如，在Canvas对象上既可能发生鼠标事件，也可能发生键盘事件，该Canvas对象就可以委托给事件监听器1来处理鼠标事件，同时委托给事件监听器2来处理键盘事件。

委托模型把事件的处理委托给外部的处理实体进行处理，实现了将事件源和监听器分开的机制。

2 事件事件分类。

按事件的性质分类java.util.EventObject类是所有事件对象的基础父类，所有事件都是由它派生出来的。

AWT的相关事件继承于java.awt.AWTEvent类，这些AWT事件分为两大类：低级事件和高级事件。

（1）低级事件低级事件是指基于组件和容器的事件，当一个组件上发生事件，如鼠标的进入、点击、拖放等，或组件的窗口开关等时，触发了组件事件。

—ComponentEvent（组件事件：组件尺寸的变化、移动）；—ContainerEvent（容器事件：组件增加、移动）；—WindowEvent（窗口事件：关闭窗口、窗口闭合、图标化）；—FocusEvent（焦点事件：焦点的获得和丢失）；—KeyEvent（键盘事件：键按下、释放）；—MouseEvent（鼠标事件：鼠标单击、移动）。

（2）高级事件（语义事件）高级事件是基于语义的事件，它可以不和特定的动作相关联，而依赖于触发此事件的类。

比如，在TextField中按Enter键会触发ActionEvent事件，滑动滚动条会触发AdjustmentEvent事件，选中项目列表的某一条就会触发ItemEvent事件。

—ActionEvent（动作事件：按钮按下，TextField中按Enter键）；—AdjustmentEvent（调节事件：在滚动条上移动滑块以调节数值）；—ItemEvent（项目事件：选择项目，不选择“项目改变”）；—TextEvent（文本事件：文本对象改变）。

3 事件监听器3.1．事件监听器基本概念事件监听器通常是一个类，该类必须实现与该事件类型相对应的接口。

对应的接口被称为事件监听器接口。

事件监听器接口类的名称与事件类的名称相对应，例如，MouseEvent事件类的监听器接口名为MouseListener。

每类事件都有监听器是接口，根据动作来定义方法。

例如，与键盘事件KeyEvent相对应的接口是：public interface KeyListener extends EventListener{public void keyPressed(KeyEvent ev);public void keyReleased(KeyEvent ev);public void keyTyped(KeyEvent ev);}注意到在本接口中有3个方法，那么Java运行时系统什么时候调用哪个方法呢？其实根据这3个方法的方法名就能够知道应该是什么时候调用哪个方法执行了。

当键盘键刚按下去时，将调用keyPr essed()方法执行；当键盘键抬起来时，将调用keyReleased()方法执行；当键盘键敲击一次时，将调用k eyTyped()方法执行。

又例如，窗口事件接口：public interface WindowListener extends EventListener{public void windowClosing(WindowEvent e);处理发生在某个GUI组件上的XxxEvent事件的某种情况，其事件处理的通用编写流程如下：（1）编写一个实现了XxxListener接口的事件监听器类；（2）在XxxListener类中用于处理该事件情况的方法中，编写处理代码；（3）调用组件的addXxxListener方法，将类XxxListener创建的实例对象注册到GUI组件上。

（1）可以声明多个接口，接口之间用逗号隔开。

…implements MouseMotionListener, MouseListener, WindowListener；（2）可以由同一个对象监听一个事件源上发生的多种事件：f.addMouseMotionListener(this);f.addMouseListener(this);f.addWindowListener(this);则对象f上发生的多个事件都将被同一个监听器接收和处理。

（3）事件监听器和事件源处在同一个类中。

本例中事件源是Frame f，事件监听器是类ThreeLis tener，其中事件源Frame f是类ThreeListener的成员变量。

（4）可以通过事件对象获得详细资料，比如，本例中就通过事件对象获得了鼠标发生时的坐标值。

public void mouseDragged(MouseEvent e){String s="Mouse dragging :X="+e.getX()+"Y="+e.getY();tf.setText(s);}根据实现事件接口的方式不同可有如下4种方法：●内部类做监听器●匿名内部类做监听器●本类做监听器●其它类做监听器例1；/* 1. inner classimport java.awt.*;import java.awt.event.*;class MyEvent extends Frame{TextField t1,t2,t3;Button b1;Label c,m;MyEvent(){t1=new TextField("100",10);t2=new TextField("200",10);t3=new TextField(10);b1=new Button("计算");c=new Label("=");m=new Label("+");add(t1);add(m);add(t2);add(c);add(t3);add(b1);b1.addActionListener(new M());setLayout(new FlowLayout());setBounds(100,100,360,200);setVisible(true);}class M implements ActionListener{public void actionPerformed(ActionEvent e) {int a=Integer.parseInt(t1.getText());int b=Integer.parseInt(t2.getText());int c=a+b;t3.setText(String.valueOf(c));}}public static void main(String[] args){new MyEvent();}}*//* 2. nameless inner classimport java.awt.*;import java.awt.event.*;class MyEvent extends Frame{TextField t1,t2,t3;Button b1;Label c,m;MyEvent(){t1=new TextField("100",10);t2=new TextField("200",10);t3=new TextField(10);b1=new Button("计算");c=new Label("=");m=new Label("+");add(t1);add(m);add(t2);add(c);add(t3);add(b1);b1.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){int a=Integer.parseInt(t1.getText());int b=Integer.parseInt(t2.getText());int c=a+b;t3.setText(String.valueOf(c));}});setLayout(new FlowLayout());setBounds(100,100,360,200);setVisible(true);}public static void main(String[] args){new MyEvent();}}*//* 3. this classimport java.awt.*;import java.awt.event.*;class MyEvent extends Frame implements ActionListener {TextField t1,t2,t3;Button b1;Label c,m;MyEvent(){t1=new TextField("100",10);t2=new TextField("200",10);t3=new TextField(10);b1=new Button("计算");c=new Label("=");m=new Label("+");add(t1);add(m);add(t2);add(c);add(t3);add(b1);b1.addActionListener(this);setLayout(new FlowLayout());setBounds(100,100,360,200);setVisible(true);}public void actionPerformed(ActionEvent e) {int a=Integer.parseInt(t1.getText());int b=Integer.parseInt(t2.getText());int c=a+b;t3.setText(String.valueOf(c)); }public static void main(String[] args) {new MyEvent();}}*//* ohter class 1import java.awt.*;import java.awt.event.*;class MyEvent extends Frame{TextField t1,t2,t3;Button b1;Label c,m;MyEvent(){t1=new TextField("100",10);t2=new TextField("200",10);t3=new TextField(10);b1=new Button("计算");c=new Label("=");m=new Label("+");add(t1);add(m);add(t2);add(c);add(t3);add(b1);b1.addActionListener(new M(this));setLayout(new FlowLayout());setBounds(100,100,360,200);setVisible(true);}public static void main(String[] args) {new MyEvent();}}class M implements ActionListener{MyEvent f1;M(MyEvent f){f1=f;}public void actionPerformed(ActionEvent e) {int a=Integer.parseInt(f1.t1.getText());int b=Integer.parseInt(f1.t2.getText());int c=a+b;f1.t3.setText(String.valueOf(c));}}*/// ohter class 2import java.awt.*;import java.awt.event.*;class MyEvent extends Frame{TextField t1,t2,t3;Button b1;Label c,m;MyEvent(){t1=new TextField("100",10);t2=new TextField("200",10);t3=new TextField(10);b1=new Button("计算");c=new Label("=");m=new Label("+");add(t1);add(m);add(t2);add(c);add(t3);add(b1);b1.addActionListener(new M(this));setLayout(new FlowLayout());setBounds(100,100,360,200);setVisible(true);}void cc(){int a=Integer.parseInt(t1.getText());int b=Integer.parseInt(t2.getText());int c=a+b;t3.setText(String.valueOf(c));}public static void main(String[] args){new MyEvent();}}class M implements ActionListener{MyEvent f1;M(MyEvent f){f1=f;}public void actionPerformed(ActionEvent e){();}}例2；/* inner classimport java.awt.*;import java.awt.event.*;class MyEvent{Frame f;Label c;void myint(){f=new Frame();c=new Label("鼠标单击点的坐标：");f.add(c);c.setBounds(20,50,300,20);f.setLayout(null);f.addMouseListener(new M());f.setBounds(100,100,350,200);f.setVisible(true);f.setFont(new Font("Arial",0,16));f.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}class M implements MouseListener //extends MouseAdapter {public void mousePressed(MouseEvent e){int x=e.getX();int y=e.getY();c.setText("鼠标单击点的坐标：("+String.valueOf(x)+","+String.valueOf(y)+")");}public void mouseReleased(MouseEvent e){}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void mouseClicked(MouseEvent e) {}public void actionPerformed(ActionEvent e){}}public static void main(String[] aa){MyEvent ff=new MyEvent();ff.myint();}}*//* nameless inner class as a monitorimport java.awt.*;import java.awt.event.*;class MyEvent{Frame f;Label c;void myint(){f=new Frame();c=new Label("鼠标单击点的坐标：");f.add(c);c.setBounds(20,50,300,20);f.setLayout(null);f.addMouseListener(new MouseListener(){public void mousePressed(MouseEvent e){int x=e.getX();int y=e.getY();c.setText("鼠标单击点的坐标：("+String.valueOf(x)+","+String.valueOf(y)+")");}public void mouseReleased(MouseEvent e){}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void mouseClicked(MouseEvent e) {}public void actionPerformed(ActionEvent e){}});f.setBounds(100,100,350,200);f.setVisible(true);f.setFont(new Font("Arial",0,16));f.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}public static void main(String[] aa){MyEvent ff=new MyEvent();ff.myint();}}*//* this classimport java.awt.*;import java.awt.event.*;class MyEvent implements MouseListener{Frame f;Label c;void myint(){f=new Frame();c=new Label("鼠标单击点的坐标：");f.add(c);c.setBounds(20,50,300,20);f.setLayout(null);f.addMouseListener(this);f.setBounds(100,100,350,200);f.setVisible(true);f.setFont(new Font("Arial",0,16));f.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}public void mousePressed(MouseEvent e){int x=e.getX();int y=e.getY();c.setText("鼠标单击点的坐标：("+String.valueOf(x)+","+String.valueOf(y)+")");}public void mouseReleased(MouseEvent e){}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void mouseClicked(MouseEvent e) {}public void actionPerformed(ActionEvent e){}public static void main(String[] aa){MyEvent ff=new MyEvent();ff.myint();}}*//* other class as a monitor 1import java.awt.*;import java.awt.event.*;class MyEvent{Frame f;Label c;void myint(){f=new Frame();c=new Label("鼠标单击点的坐标：");f.add(c);c.setBounds(20,50,300,20);f.setLayout(null);f.addMouseListener(new M(this));f.setBounds(100,100,350,200);f.setVisible(true);f.setFont(new Font("Arial",0,16));f.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}public static void main(String[] aa){MyEvent ff=new MyEvent();ff.myint();}}class M implements MouseListener{MyEvent f1;M(MyEvent f){f1=f;}public void mousePressed(MouseEvent e){int x=e.getX();int y=e.getY();f1.c.setText("鼠标单击点的坐标：("+String.valueOf(x)+","+String.valueOf(y)+")");}public void mouseReleased(MouseEvent e){}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void mouseClicked(MouseEvent e) {}public void actionPerformed(ActionEvent e){}}*/// other class as a monitor 2import java.awt.*;import java.awt.event.*;class MyEvent{Frame f;Label c;int x,y;void myint(){f=new Frame();c=new Label("鼠标单击点的坐标：");f.add(c);c.setBounds(20,50,300,20);f.setLayout(null);f.addMouseListener(new M(this));f.setBounds(100,100,350,200);f.setVisible(true);f.setFont(new Font("Arial",0,16));f.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});}void cc(){c.setText("鼠标单击点的坐标：("+String.valueOf(x)+","+String.valueOf(y)+")"); }public static void main(String[] aa){MyEvent ff=new MyEvent();ff.myint();}}class M implements MouseListener{MyEvent f1;M(MyEvent f){f1=f;}public void mousePressed(MouseEvent e){f1.x=e.getX();f1.y=e.getY();();}public void mouseReleased(MouseEvent e){} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} public void mouseClicked(MouseEvent e) {} public void actionPerformed(ActionEvent e){} }例3；import java.awt.*;import java.awt.event.*;import java.io.*;import .*;import java.util.*;import javax.imageio.*;import java.awt.image.BufferedImage;class JavaChessFive extends Panel implements MouseListener,ActionListener{Socket chessSocket;DataInputStream inData;DataOutputStream outData;String host=null;int port=4331;Panel p;TextArea t1;myImage IMG;boolean s=true;int[][] chess=new int[15][15];JavaChessFive() throws Exception {t1=new TextArea();t1.setBounds(470,100,280,350);add(t1);IMG=new myImage();IMG.setBounds(478,5,290,78);add(IMG);p=new Panel();p.setBounds(30,465,720,80);p.setBackground(Color.WHITE);add(p);setLayout(null);setSize(785,600);setBackground(Color.ORANGE);addMouseListener(this);t1.append("大家好！\n");mm();}public void paint(Graphics g){for (int i=30;i<=450;i=i+30){g.drawLine(30,i,450,i);g.drawLine(i,30,i,450);}for(int k=30;k<=450;k+=30){g.drawString(String.valueOf(k/30),k-5,20);g.drawString(String.valueOf(k/30),10,k+5);}}public void chessPaint(int chessPoint_a,int chessPoint_b) throws Exception {black_nut bn=new black_nut();white_nut wn=new white_nut();if(s){this.add(bn);bn.setBounds(chessPoint_a*30-12,chessPoint_b*30-12,24,24);t1.append("黑方走棋位置:("+chessPoint_a+","+chessPoint_b+")\n");}else{this.add(wn);wn.setBounds(chessPoint_a*30-12,chessPoint_b*30-12,24,24);t1.append("白方走棋位置:("+chessPoint_a+","+chessPoint_b+")\n");}}public void mousePressed(MouseEvent e){if (e.getModifiers()==InputEvent.BUTTON1_MASK){int x=(int)e.getX();int y=(int)e.getY();int a=(x+15)/30;int b=(y+15)/30;while(a>0 && a<=15 && b>0 && b<=15 && chess[a-1][b-1]==0) {try{chessPaint(a,b); }catch(Exception ee){}if(s) chess[a-1][b-1]=10;else chess[a-1][b-1]=1;System.out.println("win_win "+win(a-1,b-1));if(win(a-1,b-1)==2){//removeAll();//ff.setVisible(true);System.out.println("恭喜，黑方胜！");t1.append("恭喜，黑方胜！\n");}else if(win(a-1,b-1)==1){System.out.println("恭喜，白方胜！");t1.append("恭喜，白方胜！\n");}//mm();s=!s;}}}public void mouseReleased(MouseEvent e){}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void mouseClicked(MouseEvent e) {}public void actionPerformed(ActionEvent e){}void mm(){System.out.println("==============================================");for(int x=0;x<15;x++){for(int y=0;y<15;y++){System.out.print(chess[y][x]+" ");}System.out.println();}}int win(int x, int y){final int[][] cc={{0, 1},{ 1, 1},{ 1,0},{ 1,-1}};final int[][] dd={{0,-1},{-1,-1},{-1,0},{-1, 1}};int s,s1,s2,x1,y1;if(x>=0 && x<15 && y>=0 && y<15){for(int i=0;i<4;i++){s=chess[x][y];s1=chess[x][y];s2=chess[x][y];x1=x;y1=y;x1+=cc[i][0];y1+=cc[i][1];if((x1>=0) && (x1<15) && (y1>=0)&&(y1<15)){while(chess[x1][y1]==s ){s1+=chess[x1][y1];x1+=cc[i][0];y1+=cc[i][1];if(x1<0 || x1>14 || y1<0 || y1>14) break;}}x1=x;y1=y;x1+=dd[i][0];y1+=dd[i][1];if((x1>0) && (x1<15) && (y1>0)&&(y1<15)){while(chess[x1][y1]==s){s2+=chess[x1][y1];x1+=dd[i][0];y1+=dd[i][1];if(x1<0 || x1>14 || y1<0 || y1>14) break;}}System.out.println("s1+s2 :"+(s1+s2)+" "+s1+" "+s2);if((s1+s2)>=6 && (s1+s2)<=10) return 1;if((s1+s2)>=60) return 2;}return 0;}else{return 0;}}}class black_nut extends Canvas{ BufferedImage b;black_nut() throws Exception{b=ImageIO.read(new File("image/black.gif"));setSize(24,24);}public void paint(Graphics g){g.drawImage(b,0,0,null);}}class white_nut extends Canvas{ BufferedImage b;white_nut() throws Exception{b=ImageIO.read(new File("image/white.gif"));setSize(24,24);}public void paint(Graphics g){g.drawImage(b,0,0,null);}}class Test extends Frame{JavaChessFive p;Test(String s) throws Exceptionsuper(s);p=new JavaChessFive();setLayout(new BorderLayout());addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e) {System.exit(0);}});setBounds(100,100,785,600);add(p);setBackground(Color.WHITE);validate();setVisible(true);public static void main(String[] a) throws Exception {new Test("广州大学华软五子棋");}}class myImage extends Canvas{BufferedImage b;myImage() throws Exception{b=ImageIO.read(new File("image/pad11.jpg"));setSize(290,78);}public void paint(Graphics g){g.drawImage(b,0,0,null);}}4 适配器（Adapter）Java语言类的层次非常分明，它只支持单继承。