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java计算器代码总结 java计算器代码带注释( 五 )

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if (displayText.indexOf(".") == -1) {
displayText += ".";
} else if (reset) {
displayText = "0.";
}
reset = false;
}
// 当按下 0-9 时
private void numberClicked(String command) {
if (reset) {
displayText = command;
} else {
displayText += command;
}
reset = false;
}
// 运算符处理接口
interface Operator {
BigDecimal process(BigDecimal number1, BigDecimal number2);
}
// 按钮处理接口
interface Processor {
void calculate(String command);
}
}
java 计算器代码这个是最合适你了！
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Calculator extends JFrame {
private Container container;
private GridBagLayout layout;
private GridBagConstraints constraints;
private JTextField displayField;//计算结果显示区
private String lastCommand;//保存+,-,*,/,=命令
private double result;//保存计算结果
private boolean start;//判断是否为数字的开始
public Calculator() {
super("计算器");
container=getContentPane();
layout=new GridBagLayout();
container.setLayout(layout);
constraints=new GridBagConstraints();
start=true;
result=0;
lastCommand = "=";
displayField=new JTextField(20);
displayField.setText("0.0");
displayField.setcolor(red);
displayField.setHorizontalAlignment(JTextField.RIGHT);
constraints.gridx=0;
constraints.gridy=0;
constraints.gridwidth=4;
constraints.gridheight=1;
constraints.fill=GridBagConstraints.BOTH;
constraints.weightx=100;
constraints.weighty=100;
layout.setConstraints(displayField,constraints);
container.add(displayField);
ActionListener insert = new InsertAction();
ActionListener command = new CommandAction();
addButton("7",0,2,1,1,insert);
addButton("8",1,2,1,1,insert);
addButton("9",2,2,1,1,insert);
addButton("/",3,5,1,1,command);
addButton("4",0,3,1,1,insert);
addButton("5",1,3,1,1,insert);
addButton("6",2,3,1,1,insert);
addButton("*",3,4,1,1,command);
addButton("1",0,4,1,1,insert);
addButton("2",1,4,1,1,insert);
addButton("3",2,4,1,1,insert);
addButton("-",3,3,1,1,command);
addButton("0",1,5,1,1,insert);
addButton("=",2,5,1,1,command);
addButton(".",0,5,1,1,insert);
addButton("+",3,2,1,1,command);
setSize(180,200);
setVisible(true);
}
private void addButton(String label,int row,int column,int with,int height,ActionListener listener) {
JButton button=new JButton(label);
constraints.gridx=row;
constraints.gridy=column;
constraints.gridwidth=with;
constraints.gridheight=height;
constraints.fill=GridBagConstraints.BOTH;
button.addActionListener(listener);
layout.setConstraints(button,constraints);
container.add(button);
}
private class InsertAction implements ActionListener {
public void actionPerformed(ActionEvent event) {
String input=event.getActionCommand();
if (start) {
displayField.setText("");
start=false;
displayField.setText(displayField.getText()+input);
}
}
}
private class CommandAction implements ActionListener {
public void actionPerformed(ActionEvent evt) {
String command=evt.getActionCommand();
if(start) {
lastCommand=command;
}else {
calculate(Double.parseDouble(displayField.getText()));
lastCommand=command;
start=true;
}
}
}
public void calculate(double x) {
if (lastCommand.equals("+")) result+= x;
else if (lastCommand.equals("-")) result-=x;
else if (lastCommand.equals("*")) result*=x;
else if (lastCommand.equals("/")) result/=x;

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