怎么把这个计算器加上0-9的按钮，然后点击按钮数字显示在文本框中
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Xiti8_5
{ public static void main(String args[])
{ ComputerFrame fr=new ComputerFrame();
fr.setTitle("计算");
}
}
class ComputerFrame extends JFrame implements ActionListener
{ JTextField text1,text2,text3;
JButton button1,button2,button3,button4;
JLabel label;
public ComputerFrame()
{setLayout(new FlowLayout());
text1=new JTextField(10);
text2=new JTextField(10);
text3=new JTextField(10);
label=new JLabel(" ",JLabel.CENTER);
label.setBackground(Color.green);
add(text1);
add(label);
add(text2);
add(text3);
button1=new JButton("加");
button2=new JButton("减");
button3=new JButton("乘");
button4=new JButton("除");
add(button1);
add(button2);
add(button3);
add(button4);
button1.addActionListener(this);
button2.addActionListener(this);
button3.addActionListener(this);
button4.addActionListener(this);
setSize(400,320);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
validate();
}
public void actionPerformed(ActionEvent e)
{ double n;
if(e.getSource()==button1)
{ double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1+n2;
text3.setText(String.valueOf(n));
label.setText("+");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
else if(e.getSource()==button2)
{ double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1-n2;
text3.setText(String.valueOf(n));
label.setText("-");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
else if(e.getSource()==button3)
{double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1*n2;
text3.setText(String.valueOf(n));
label.setText("*");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
else if(e.getSource()==button4)
{double n1,n2;
try{ n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=n1/n2;
text3.setText(String.valueOf(n));
label.setText("/");
}
catch(NumberFormatException ee)
{ text3.setText("请输入数字字符");
}
}
validate();
}
}
我来给你写一个，望采纳！！！点击回答右侧采纳即可！！
演示代码如下：仅供参考
import java.awt.*;
import java.awt.event.*;
import java.math.BigDecimal;
import javax.swing.*;
//创建计算器Calculator类，实现ActionListener接口
public class jsq implements ActionListener {
//定义变量和按钮数组
private String[] names = {"Backspace","CE","C","+","7","8","9","-",
"4","5","6","*","1","2","3","/","0","+/-",".","="
};
private JButton[] buttonArray = new JButton[names.length];
private boolean append = false;//默认追加为false
private String operator = "+";//默认运算符为“+”
private String s1 = "0";//默认字符为0
private String ss = "0";//默认字符为0
//创建可以显示20个字符的文本框
JTextField jtf = new JTextField(20);
//构造方法
public jsq() {}
public jsq(String title) {
//创建窗口、面板，并设置面板布局为网格布局
JFrame jf = new JFrame(title);
JPanel jp = new JPanel();
jp.setLayout(new GridLayout(5,4));
//依次添加按钮到面板中，并为按钮注册监听器
for (int i = 0; i < buttonArray.length; i++) {
buttonArray[i] = new JButton(names[i]);
buttonArray[i].addActionListener(this);
jp.add(buttonArray[i]);
}
//添加文本框到窗体中
jf.add(jtf,BorderLayout.NORTH);
jf.add(jp);//添加面板到窗体中
jtf.setHorizontalAlignment(JTextField.RIGHT);//设置文本框的水平方向为右
jtf.setText("0");//设置初始文本为0
jtf.setEditable(false);//设置文本框为不可编辑状态
//设置窗体属性
jf.pack();//系统自动设置大小和位置
jf.setVisible(true);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
//实现监听接口的actionPerformed方法
public void actionPerformed(ActionEvent e) {
String comm = e.getActionCommand();
if(comm.matches("\\d")) { //用正则表达式判断输出的是否是0~9
if(append) { //如果是，追加显示
String temp = jtf.getText();
jtf.setText(temp + comm);
} else { //如果不是，显示该字符并将追加设置为true
jtf.setText(comm);
append = true;
}
} else if(comm.equals(".")) { //输入小数点时
String temp = jtf.getText();
if(temp.indexOf(".")== -1 && append) { //当输入的文本中没有小数点时
jtf.setText(temp+comm);
append = true; //输入小数点后继续追加
} else if(!append) { //当字符串开始时候先输入 " . " 则直接输出" 0. "
jtf.setText("0"+comm);
append = true;
}
} else if("+-*/".indexOf(comm)!= -1) { //输入加减乘除符号时，
//以下运算应该注意数据类型，尤其是大数字和浮点数及int数在运算中的区别
operator = comm;
s1 = jtf.getText();
double d3 = Double.parseDouble(s1);
double d4 = Double.parseDouble(ss);
BigDecimal bd3 = new BigDecimal(d3+"");
BigDecimal bd4 = new BigDecimal(d4+"");
if(operator.equals("+")) { //加法时
d3 = bd3.add(bd4).doubleValue();
ss = d3+"";
jtf.setText(ss);
} else if(operator.equals("-")) { //减法时
if(d4 == 0.0) {
ss = s1;
jtf.setText(ss);
} else {
d3 = bd4.subtract(bd3).doubleValue();
ss = d3+"";
jtf.setText(ss);
}
} else if(operator.equals("*")) { //乘法时
if(d4 == 0.0) {
ss = s1;
jtf.setText(ss);
} else {
d3 = bd3.multiply(bd4).doubleValue();
ss = d3+"";
jtf.setText(ss);
}
} else if(operator.equals("/")) { //除法时
if(d4 == 0.0) {
ss = s1;
jtf.setText(s1);
} else {
d3 = bd4.divide(bd3,15,BigDecimal.ROUND_HALF_UP).doubleValue();
}
ss = d3+"";
jtf.setText(ss);
}
append = false; //不继续追加
} else if(comm.equals("=")) { //输入等号时，计算加减乘除的结果
String s2 = jtf.getText();
double d1 = Double.parseDouble(ss);
double d2 = Double.parseDouble(s2);
BigDecimal bd1 = new BigDecimal(d1+"");
BigDecimal bd2 = new BigDecimal(d2+"");
if(operator.equals("+")) {
d1 = bd1.add(bd2).doubleValue();
} else if(operator.equals("-")) {
d1 = bd1.subtract(bd2).doubleValue();
} else if(operator.equals("*")) {
d1 = bd1.multiply(bd2).doubleValue();
} else if(operator.equals("/")) { //精确计算浮点除法
if(d2!=0.0) {
d1 = bd1.divide(bd2,15,BigDecimal.ROUND_HALF_UP).doubleValue();
}
}
ss = "0";
jtf.setText(d1+"");
append = false; //不继续追加
} else if(comm.equals("CE")||comm.equals("C")) { //输入CE或C时
jtf.setText("0");
ss = "0";
append = false;
} else if(comm.equals("+/-")) { //改变数值的正负号
String temp = jtf.getText();
if(!append) {
jtf.setText("-");
append = true;
} else if(temp.startsWith("-")) { //如果字符串以负号开头
jtf.setText(temp.substring(1));
} else {
jtf.setText("-" + temp);
}
} else if(comm.equals("Backspace")) { //输入Backspace时，退回一个字符
String temp = jtf.getText();
if(temp.length()>0)
jtf.setText(temp.substring(0,temp.length()-1));
}
}
//主方法
public static void main(String[] args) {
//创建名为Calculator的计算器对象
new jsq("计算器");
}
}
运行截图展示：
