我有两个不同的类。是的,他们在同一个项目中,包装一切。这个项目来自Yakov Fain的一本书:Java Programming for Kids,Parents,and Grandparents。页数:95-100。您可以轻松获得该书的PDF。下面是两个不同类别的名称。为了我将展示我的两个班。Java中的计算器,不工作
类是计算器本身:在运行计算器计算器
类:CalculatorEngine
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.GridLayout;
public class Calculator {
JButton button0 = new JButton("0");
JButton button1 = new JButton("1");
JButton button2 = new JButton("2");
JButton button3 = new JButton("3");
JButton button4 = new JButton("4");
JButton button5 = new JButton("5");
JButton button6 = new JButton("6");
JButton button7 = new JButton("7");
JButton button8 = new JButton("8");
JButton button9 = new JButton("9");
JButton buttonPoint = new JButton(".");
JButton buttonEqual = new JButton("=");
JButton buttonPlus = new JButton("+");
JButton buttonSub = new JButton("-");
JButton buttonMult = new JButton("*");
JButton buttonDiv = new JButton("/");
JPanel windowContent = new JPanel();
JTextField displayField = new JTextField(30);
Calculator() {
BorderLayout bl = new BorderLayout();
windowContent.setLayout(bl);
windowContent.add("North", displayField);
JPanel p1 = new JPanel();
GridLayout gl = new GridLayout(4, 3);
p1.setLayout(gl);
p1.add(button0);
p1.add(button1);
p1.add(button2);
p1.add(button3);
p1.add(button4);
p1.add(button5);
p1.add(button6);
p1.add(button7);
p1.add(button8);
p1.add(button9);
p1.add(buttonPoint);
p1.add(buttonEqual);
windowContent.add("Center", p1);
JPanel p2 = new JPanel();
GridLayout gl2 = new GridLayout(4, 1);
p2.setLayout(gl2);
p2.add(buttonDiv);
p2.add(buttonMult);
p2.add(buttonSub);
p2.add(buttonPlus);
windowContent.add("East", p2);
JFrame frame = new JFrame("Calculator");
frame.setContentPane(windowContent);
frame.pack();
frame.setVisible(true);
CalculatorEngine calcEngine = new CalculatorEngine(this);
button0.addActionListener(calcEngine);
button1.addActionListener(calcEngine);
button2.addActionListener(calcEngine);
button3.addActionListener(calcEngine);
button4.addActionListener(calcEngine);
button5.addActionListener(calcEngine);
button6.addActionListener(calcEngine);
button7.addActionListener(calcEngine);
button8.addActionListener(calcEngine);
button9.addActionListener(calcEngine);
buttonDiv.addActionListener(calcEngine);
buttonMult.addActionListener(calcEngine);
buttonSub.addActionListener(calcEngine);
buttonPlus.addActionListener(calcEngine);
buttonPoint.addActionListener(calcEngine);
buttonEqual.addActionListener(calcEngine);
}
public static void main(String[] args) {
Calculator calc = new Calculator();
}
}
*这是Calculator类。
**下面是运行Calculator类的代码。
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
public class CalculatorEngine implements ActionListener {
Calculator parent;
char selectedAction = ' ';
double currentResult = 0;
CalculatorEngine(Calculator parent) {
this.parent = parent;
}
public void actionPerformed(ActionEvent e) {
JButton clickedButton = (JButton) e.getSource();
String dispFieldText = parent.displayField.getText();
double displayValue = 0;
if (!"".equals(dispFieldText)) {
displayValue = Double.parseDouble(dispFieldText);
}
Object src = e.getSource();
if (src == parent.buttonPlus) {
selectedAction = '+';
currentResult = displayValue;
parent.displayField.setText("");
} else if (src == parent.buttonSub) {
selectedAction = '-';
currentResult = displayValue;
parent.displayField.setText("");
} else if (src == parent.buttonMult) {
selectedAction = '*';
currentResult = displayValue;
parent.displayField.setText("");
} else if (src == parent.buttonDiv) {
selectedAction = '/';
currentResult = displayValue;
parent.displayField.setText("");
if (selectedAction == '+') {
currentResult += displayValue;
parent.displayField.setText("" + currentResult);
} else if (selectedAction == '-') {
currentResult -= displayValue;
parent.displayField.setText("" + currentResult);
} else if (selectedAction == '*') {
currentResult *= displayValue;
parent.displayField.setText("" + currentResult);
} else if (selectedAction == '/') {
currentResult /= displayValue;
parent.displayField.setText("" + currentResult);
}
} else {
String clickedButtonLabel = clickedButton.getText();
parent.displayField.setText(dispFieldText + clickedButtonLabel);
}
}
}
这两个类显示计算器到控制台,看起来是这样的: (https://i.stack.imgur.com/Y4XHE.png)
每当我运行该程序,我把一个等式,例如:1 + 1,然后我按'=',程序不会运行,并且在这种情况下不会给出等式2的结果。我也查看了书中的代码,它是相同的,或者我认为它是相同的。
你可能想把eclipse拿掉标题 – SaggingRufus
好吧,会的。谢谢! –
范围界定问题。你只在处理'/'的块中执行计算。 – EJP