我正在尝试使用swing制作一个计算器,但是当我编译它时我遇到了一个问题,这是一个错误,类AbstractButton中的方法addActionListener无法应用于给定的类型。
我的代码是
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Calculator extends JFrame implements ActionListener {
private String str = "0";
JTextField l_tf = new JTextField(100);
JButton button[] = new JButton[31];
Northwindow panelNorth = new Northwindow();
Centerwindow panelCenter = new Centerwindow();
Calculator(String l_s) {
getContentPane().setLayout(new BorderLayout());
getContentPane().add("North", panelNorth);
getContentPane().add("Center", panelCenter);
setSize(300, 400);
setVisible(true);
}
//Northwindow
class Northwindow extends JPanel {
public Northwindow() {
Dimension textf = new Dimension(50, 50);
setLayout(new GridLayout(0, 1));
setBackground(new Color(230, 230, 255));
l_tf.setPreferredSize(textf);
add(l_tf);
}
}
class Centerwindow extends JPanel {
public Centerwindow() {
setLayout(new GridLayout(0, 4));
String key[] = {"ON", "Del", "C", "+/-", "1/x", "7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+", "Sqrt", "Sqr", "Sin", "Cos", "^", "log", "ln", "tan", "(", ")", "pie"};
Dimension but = new Dimension(80, 30);
for (int i = 0; i < button.length; i++) {
button[i] = new JButton(key[i]);
button[i].setPreferredSize(but);
add(button[i]);
button[i].addActionListener(this);
//before the on button is not clicked
for (i = 0; i < button.length; i++)
button[i].setEnable(false);
l_tf.setEditable(false);
}
}
}
public void actionPerformed(ActionEvent e) {
if (e.getSource == button[0]) // ON button
{
l_tf.setBackground(color.white);
button[0].setLabel("OFF");
for (i = 0; i < button.length; i++)
button[i].setEnable(true);
l_tf.setEditable(true);
l_tf.setText(str);
}
if (e.getSource == button[1]) {
}
}
public static void main(String... s) {
Calculator c = new Calculator("Calculator");
}
}
答案 0 :(得分:4)
button[i].addActionListener(this);
这显示在Centerwindow
内,但未实现ActionListener
。由于Centerwindow
是一个内部类,因此您可以访问封闭的Calculator
实例并添加它,如果这是您要执行的操作:
button[i].addActionListener(Calculator.this);