java - "The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments"

Question

我是一名初学者程序员，我在操作监听器和 GUI 方面遇到了问题。这是我的代码:

主类--

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class prog extends JFrame {

//add instance variable to hold lockd
prog app = new prog();

//create buttons
JPanel row1 = new JPanel();
JButton oneLeft = new JButton("oneLeft");
JButton oneRight = new JButton("oneRight");

JPanel row2 = new JPanel();
JButton twoLeft = new JButton("twoLeft");
JButton twoRight = new JButton("twoRight");

JPanel row3 = new JPanel();
JButton threeLeft = new JButton("threeLeft");
JButton threeRight = new JButton("threeRight");


public prog() {
    super("Prog");
    setLookAndFeel();
    setSize(400, 800);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    GridLayout layout = new GridLayout(3, 2);
    setLayout(layout);

    //add Listeners
    oneLeft.addActionListener(app);
    oneRight.addActionListener(app);
    twoLeft.addActionListener(app);
    twoRight.addActionListener(app);
    threeLeft.addActionListener(app);
    threeRight.addActionListener(app);



    setVisible(true);
}

private void setLookAndFeel() {
    try {
        UIManager.setLookAndFeel("com.sun.java.plaf.");
    } catch (Exception e) {
        //ignore error
    }
}

public static void main(String[] args) {
    prog progApp = new prog();
}
}

我在此类中使用操作监听器时遇到错误:AbstractButton 类型中的方法 addActionListener(ActionListener) 不适用于参数 (prog)。

完整错误:

Description Resource    Path    Location    Type
The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (prog)  prog.java   /Experiment/src line 33 Java Problem
The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (prog)  prog.java   /Experiment/src line 35 Java Problem
The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (prog)  prog.java   /Experiment/src line 34 Java Problem
The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (prog)  prog.java   /Experiment/src line 37 Java Problem
The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (prog)  prog.java   /Experiment/src line 36 Java Problem
The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (prog)  prog.java   /Experiment/src line 38 Java Problem

这是我的监听器类:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class progEvent implements ActionListener {

prog GUI;
String newLine = System.getProperty("line.separater");


public progEvent(prog in) {
    GUI = in;
}

public void actionPerformed(ActionEvent event) {
    String command = event.getActionCommand();
    try {
        File numClicks = new File("numClicks.properties");
        FileOutputStream outStream = new FileOutputStream(numClicks);

        if (command.equals("oneLeft")) {
            write(outStream, "oneLeft has been clicked.");  
        }
        if (command.equals("oneRight")) {
            write(outStream, "oneRight has been clicked.");
        }
        if (command.equals("twoLeft")) {
            write(outStream, "twoLeft has been clicked.");
        }
        if (command.equals("twoRight")) {
            write(outStream, "twoRight has been clicked.");
        }
        if (command.equals("threeLeft")) {
            write(outStream, "threeLeft has been clicked.");
        }
        if (command.equals("threeRight")) {
            write(outStream, "threeRight has been clicked.");
        }
    } catch (IOException ioe) {
        System.out.println("The file could not be written to.");
    }
}

void write(FileOutputStream stream, String output) throws IOException {
    output = output + newLine;
    byte[] data = output.getBytes();
    stream.write(data, 0, data.length);
}
}

我也无法显示我的 GUI。我正在使用一本书来学习它，并使用一个类作为该实验的模板。但我完全卡住了。谢谢!

Answer 1

您正在尝试添加 prog 类的实例作为 ActionListener，但您的 ActionListener 是 progEvent 代替。您需要添加一个 progEvent Listener = new progEvent();，然后添加 addActionListener(progEvent)。

(此外，您在系统属性中拼错了“分隔符”；您将无法检索到您要查找的内容。)