四、综合应用题(共18分)
本题的功能是定义自已的组件类。窗口中排布着12
个按钮,鼠标移动按钮时,按钮背景颜色改变,用鼠标单击
按钮时,后台将显示该按钮对应的字符。
import java.awt.*;
import java.awt.event.*;
import java.util.*;
class java3 extends Frame{
String keys="l23456789*0#";
java3(){
super("java3");
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(O);
}
});
setLayout(new GridLayout(4,3,6,6));
for(int i=0;i KeyButton kb=new KeyButton(keys.charAt
(i));
kb.addkeyListener(this);
kb.setBackground(Color.pink);
kb.setForeground(Color.black);
add(kb);
}
setSize(200,200);
show();
}
class KeyEventHandler extends KeyAdapter{
public void keyTyPed(KeyEvent evt){
System.out.println(evt.getChar());
}
}
public static void main(String[]args){
newjava3();
}
}
class KeyButton extends Component{
KeyListener keyListener;
boolean highlighted;
char key;
KeyButton(char k){
this.key=k;
addMouseListener(new MouseEventHandler()):
}
public void paint(Graphics g){
int W=getSize().width;
int h=getSize().height;
String s=""+key;
FontMetrics fm=g.getFontMetrics();
if(highlighted){
g.setColor(getBackground());
g.fillRoundRect(0,0,w-1,h-1,10,10);
}
g.setColor(getForeground());
g.drawRoundRect(0,0,w-1,h-1,10,10);
g.drawString(s,(w-fm.stringWidth(s))/2,
(h-fm.getHeight())/2+fm.getAscent());
}
class MouseEventHandler extends MouseAdapter{
public void mousePressed(MouseEvent evt){
if(keyListener!=null){
keyListener.keyTyped(
new KeyEvent(KeyButton.this,KeyEvent.KEY_
TYPED,
System.currentTimeMillis(),
0,KeyEvent.VK_UNDEFINED,key));
}
}
public void mouseEntered(MouseEvent evt){
highlighted=true;
repaint();
}
public void mouseExited(MouseEvent evt){
highlighted=false;
repaint();
}
}
public synchronized void addKeyListerner(KeyLis-
tener l){
keyListener=AWTEventMuhieaster.add(key-
Listener,1);
}
public synchronized void removeKeyListener(Key-
Listener l){
keyListener=AWTEventMuhicaster.remove
(keyListener,1);
}
}
正在阅读:
2021吉林省四平市铁东区基层卫生专业技术“县聘乡用”专项招聘入选人员公示公告11-05
二年级上册语文教案:秋天02-23
追求作文500字01-17
小学四年级寒假趣事日记500字4篇09-28
妈妈,我想对您说作文500字11-26
数学知识:几何学是什么时候发明的10-27
有你相伴真好作文600字08-28
感恩与青春同行作文800字11-14
除夕夜温馨祝福句子大全【三篇】10-01