1.简单计算器
使用AWT编程，FrameNORTH区域放置TextField组件，将指定为4行5列GridLayout布局管理器的Panel放置于Frame中部区域，其中填充操作符和操作数按钮。
按钮触发事件源，对按钮添加ActionListener注册监听。自定义NumListener（操作数监听类）、OperatListener（操作符监听类）、EqualListener（’=‘符监听类）和匿名内部类（如b[11]’-'符监听类）分情况对按钮事件进行监听并响应。
注意：整数、浮点、负数以及连续运算均可以。
代码：
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import static java.awt.Color.blue;
public class Calculation {
//操作数
double x,y;
String op;
boolean flag;
Frame frame = new Frame("智子的计算器！");
TextField tf = new TextField(30);
Button[] b = new Button[20];
public void init(){
//北部区域放置文本框
frame.add(tf,BorderLayout.NORTH);
Panel panel = new Panel();
panel.setLayout(new GridLayout(4,5,2,2));
//设置按钮
String s = "+-*/%";
for(int i=0;i<10;i++) {//运算数
b[i] = new Button(i + "");
b[i].setForeground(blue);
}
for(int i=0;i<5;i++) {//运算符
b[i+10]=new Button(s.charAt(i)+"");
b[i+10].setForeground(blue);
}
String[] t = {"sqrt","^2","^3","=","."};
for(int i=0;i<5;i++){
b[i+15]=new Button(t[i]);
b[i+15].setForeground(blue);
}
//按钮注册监听
for (int i = 0; i < 10; i++) {//操作数注册监听
b[i].addActionListener(new NumListener());
}
for (int i = 10; i < 18; i++) {//操作符注册监听
if(i==11) continue;
b[i].addActionListener(new OperatListener());
}
b[11].addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if(!flag){
tf.setText("-");
flag = true;
} else {
x = Double.parseDouble(tf.getText());
op = e.getActionCommand();
flag = false;
}
}
});
//“=”注册监听
b[18].addActionListener(new EqualListener());
//“.”注册监听
b[19].addActionListener(new NumListener());
//将按钮加入panel
for (int i = 0; i < 20; i++) {
panel.add(b[i]);
}
//设置中部按钮
frame.add(panel);
//窗口监听器 注册监听
frame.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
//设置窗口最优并可见
frame.pack();
frame.setVisible(true);
}
//数字按钮监听器类
public class NumListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
String t = e.getActionCommand();
String s = tf.getText();
if(flag==false)
tf.setText(t);
else
tf.setText(s+t);
flag = true;
}
}
//操作符按钮监听器类
public class OperatListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
x = Double.parseDouble(tf.getText());
op = e.getActionCommand();
flag = false;
}
}
//等号按钮监听器类
public class EqualListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
y = Double.parseDouble(tf.getText());
flag = true;
switch(op){
case "+":tf.setText(x+y+"");
break;
case "-":tf.setText(x-y+"");
break;
case "*":tf.setText(x*y+"");
break;
case "/":
if(y!=0)
tf.setText(x/y+"");
else
tf.setText("inf");
break;
case "%":tf.setText(x%y+"");
break;
case "sqrt":tf.setText((int)Math.sqrt(x)+"");
break;
case "^2":tf.setText(y*y+"");
break;
case "^3":tf.setText(y*y*y+"");
break;
}
}
}
public static void main(String[] args) {
new Calculation().init();
}
}到此这篇关于 Java图形化界面编程实现简单计算器的文章就介绍到这了,更多相关 Java图形化界面编程实现计算器内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！
