使用java的AWT包实现一个简易的计算器。
代码语言：javascript复制import java.awt.*;
import java.awt.event.*;
public class Calculator {
private Frame frame;
private Label label;
private Panel panel;
private Button button0,button1,button2,button3,button4,button5,button6,button7,button8,
button9,buttonequ,buttondiv,buttondot,buttonmul,buttonsub,buttonadd;
private ButtonHandler listener;
public Calculator() {
frame = new Frame("My Calculator");
label = new Label("0", Label.RIGHT);
panel = new Panel(new GridLayout(4, 4));
button0 = new Button("0");
button1 = new Button("1");
button2 = new Button("2");
button3 = new Button("3");
button4 = new Button("4");
button5 = new Button("5");
button6 = new Button("6");
button7 = new Button("7");
button8 = new Button("8");
button9 = new Button("9");
buttonequ = new Button("=");
buttondiv = new Button("/");
buttondot = new Button(".");
buttonmul = new Button("*");
buttonsub = new Button("-");
buttonadd = new Button(" ");
panel.add(button7);
panel.add(button8);
panel.add(button9);
panel.add(buttonadd);
panel.add(button4);
panel.add(button5);
panel.add(button6);
panel.add(buttonsub);
panel.add(button1);
panel.add(button2);
panel.add(button3);
panel.add(buttonmul);
panel.add(button0);
panel.add(buttondot);
panel.add(buttonequ);
panel.add(buttondiv);
frame.add(label, BorderLayout.NORTH);
frame.add(panel, BorderLayout.CENTER);
frame.pack();
frame.setSize(300,300);
frame.setVisible(true);
listener = new ButtonHandler();
//对按钮添加监听
button0.addActionListener(listener);
button1.addActionListener(listener);
button2.addActionListener(listener);
button3.addActionListener(listener);
button4.addActionListener(listener);
button5.addActionListener(listener);
button6.addActionListener(listener);
button7.addActionListener(listener);
button8.addActionListener(listener);
button9.addActionListener(listener);
buttonadd.addActionListener(listener);
buttonsub.addActionListener(listener);
buttonmul.addActionListener(listener);
buttondiv.addActionListener(listener);
buttondot.addActionListener(listener);
buttonequ.addActionListener(listener);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}
class ButtonHandler implements ActionListener {
int flag = 0; //存储运算符
boolean equHappened = true;
double arg1 = 0, arg2 = 0, result = 0;
//@Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() == buttonequ) {
equHappened = true;
if(flag==0) {
result = arg1 arg2;
}
else if(flag==1) {
result = arg1 - arg2;
}
else if(flag==2) {
result = arg1 * arg2;
}
else {
result = arg1 / arg2;
}
label.setText(result "");
}
else {
if(equHappened == true) {
label.setText("");
equHappened = false;
}
if(e.getSource() == buttondot) {
label.setText("0.");
}
else if(e.getSource() == button0) {
label.setText(label.getText() "0");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button1) {
label.setText(label.getText() "1");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button2) {
label.setText(label.getText() "2");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button3) {
label.setText(label.getText() "3");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button4) {
label.setText(label.getText() "4");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button5) {
label.setText(label.getText() "5");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button6) {
label.setText(label.getText() "6");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button7) {
label.setText(label.getText() "7");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button8) {
label.setText(label.getText() "8");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == button9) {
label.setText(label.getText() "9");
arg2 = Double.parseDouble(label.getText());
}
else if(e.getSource() == buttonadd) {
label.setText("");
arg1 = arg2;
flag = 0;
}
else if(e.getSource() == buttonsub) {
label.setText("");
arg1 = arg2;
flag = 1;
}
else if(e.getSource() == buttonmul) {
label.setText("");
arg1 = arg2;
flag = 2;
}
else if(e.getSource() == buttondiv) {
label.setText("");
arg1 = arg2;
flag = 3;
}
}
}
}
public static void main(String[] args) {
Calculator cal = new Calculator();
}
}并不难，只用到了AWT，一个小时做完，感兴趣的可以用swing改写一下。
