Question

我遵循了如何执行此操作的教程 - 这是我使用的代码：

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

public class Soundboard {

    JButton Button1;

    public void windowCreate() {
        JFrame frame = new JFrame();
        mainsPanel = new JPanel();

        Button1 = new JButton("1");
        Button1.addActionListener(this);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.add(Button1);
        frame.add(mainsPanel);

        frame.setSize(183,245);
        frame.setVisible(true);
        frame.setLocationRelativeTo(null);
    }

    public void actionPerformed(ActionEvent event){
    }

    public static void main(String[] args){
    Soundboard window = new Soundboard();
    window.windowCreate();
    }
}

代码似乎不起作用。谁能解释为什么？

JPanel用作背景。问题发生在Button1.addActionListener(this);，因为它说＆＃34;这个＆＃34;不能转换为ActionListener或类似的东西。

Answer 1

如果要覆盖ActionListener方法，则需要实现actionPerformed接口：

public class Soundboard implements ActionListener {

Answer 2

如果您想将您的课程添加为Onclicklistener：

Button1.addActionListener(this);

那么你的类必须实现适当的接口ActionListener，如下所示：

public class Soundboard implements ActionListener{
    //...

    @Override
    public void actionPerformed(ActionEvent e){
    //...
    }
}

修改

如果你有多个按钮，需要分开实现，你可以f.e.使用匿名类：

mybutton.addActionListener(new ActionListener(){ @Override public void actionPerformed(ActionEvent e){ //does something, that probably interests only mybutton //declare mybutton as **final** if you must use it } });

Answer 3

您只能ActionListener添加Component addActionListener()。

您的班级必须实施ActionListener例如

public class Soundboard implements ActionListener {

Answer 4

我得到了它的工作。这是我实现它的方式，其他按钮还没有做到。所有代码都在一个名为Soundboard的类中，它实现了ActionListener，而javax.swing *和 java.awt.event *也被导入。

JButton loadButton;
JButton clearButton;
JButton Button1;
JButton Button2;
JButton Button3;
JButton Button4;
JPanel mainsPanel;
int times;

public void windowCreate() {


    JFrame frame = new JFrame();
    mainsPanel = new JPanel();


    loadButton = new JButton("Load...");
    loadButton.setSize(80, 30);
    loadButton.setLocation(4, 4);

    clearButton = new JButton("Clear");
    clearButton.setSize(80, 30);
    clearButton.setLocation(92, 4);


    Button1 = new JButton("1");
    Button1.setSize(80, 80);
    Button1.setLocation(4, 45);
    Button2 = new JButton("2");
    Button2.setSize(80, 80);
    Button2.setLocation(92, 45);
    Button3 = new JButton("3");
    Button3.setSize(80, 80);
    Button3.setLocation(4, 133);
    Button4 = new JButton("4");
    Button4.setSize(80, 80);
    Button4.setLocation(92, 133);

    loadButton.addActionListener(this);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setResizable(false);

    frame.add(loadButton);
    frame.add(clearButton);
    frame.add(Button1);
    frame.add(Button2);
    frame.add(Button3);
    frame.add(Button4);
    frame.add(mainsPanel);

    frame.setSize(183,245);
    frame.setVisible(true);
    frame.setLocationRelativeTo(null);                
}
@Override
public void actionPerformed(ActionEvent event){
    times += 1;
    System.out.println("Test successful - this was the #"
                        + times + " press");
}

public static void main(String[] args){
    Soundboard window = new Soundboard();
    window.windowCreate();
}

actionListener无法正常工作

4 个答案: