用java编写一个简易的计算器代码.doc

importjava.awt.BorderLayout;
importjava.awt.Color;
importjava.awt.GridLayout;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjava.awt.event.KeyEvent;
importjava.awt.event.KeyListener;

importjavax.swing.JButton;
importjavax.swing.JFrame;
importjavax.swing.JPanel;
importjavax.swing.JTextField;

/*使用java语言开发一个简易计算器
*
*
*/
publicclassTestJsqextendsJFrameimplementsActionListener,KeyListener{
privateJTextFieldjtf;
privateJButtonjb_bk,jb_ce,jb_c;
privateStringxs="";
privatedoublesum=0;
privateintfh;

publicstaticvoidmain(String[]args){
newTestJsq().creatCUI();

}

publicvoidcreatCUI(){
JFramejf=newJFrame();
jf.setTitle("计算器");
jtf=newJTextField("0.");
jtf.setHorizontalAlignment(JTextField.RIGHT);
jf.add(jtf,BorderLayout.NORTH);
JPaneljp_main=newJPanel(newBorderLayout());
jf.add(jp_main);
JPaneljp1=newJPanel(newGridLayout(1,3,1,1));
jb_bk=newJButton("Backspace");
jb_bk.setForeground(Color.RED);
jb_bk.addActionListener(this);
jb_ce=newJButton("CE");
jb_ce.setForeground(Color.RED);
jb_ce.addActionListener(this);
jb_c=newJButton("C");
jb_c.setForeground(Color.RED);
jb_c.addActionListener(this);
jp1.add(jb_bk);
jp1.add(jb_ce);
jp1.add(jb_c);
jp_main.add(jp1,BorderLayout.NORTH);
JPaneljp2=newJPanel(newGridLayout(4,5,1,1));
Stringstr[]={"7","8","9","/","sqrt","4","5","6","*","%",
"1","2","3","-","1/x","0","+/-",".","+","="};
for(inti=0;i<20;i++){
JButtonjb=newJButton(str[i]);
jb.addActionListener(this);
jb.setForeground(Color.blue);
if(i==3||i==8||i==13||i==18||i==19){
jb.setForeground(Color.RED);
}
jp2.add(jb);
}
jp_main.add(jp2,BorderLayout.CENTER);
jf.setResizable(false);
jf.setBounds(50,50,350,350);
jf.setVisible(true);

}

@Override
publicvoidactionPerformed(ActionEvente){
Strings=e.getActionCommand();
if(s.equals("CE")||s.equals("C")){
xs="";
jtf.setText("0.");

}elseif(s.equals("Backspace")){
Stringstr=xs.substring(0,xs.length()-1)