Question

所以我有一段看起来像这样的代码......

public IPGUI() {
        setTitle("IP Extractor");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 250, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);

        JPanel panel = new JPanel();
        contentPane.add(panel, BorderLayout.CENTER);
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));

        JButton btnConvertDocuments = new JButton("1. Convert Documents");
        btnConvertDocuments.setAlignmentX(Component.CENTER_ALIGNMENT);
        btnConvertDocuments.setMaximumSize(new Dimension(160, 0));
        btnConvertDocuments.setPreferredSize(new Dimension(0, 50));

        panel.add(btnConvertDocuments);
        btnConvertDocuments.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                //FileConverter fc = new FileConverter();
                            //Why wont the above method work?
            }
        });

        JSeparator separator_3 = new JSeparator();
        panel.add(separator_3);

当我点击按钮时，这就是产生的错误：

Exception in thread "AWT-EventQueue-0" java.lang.Error: Unresolved compilation problems: 
    FileConverter cannot be resolved to a type
    FileConverter cannot be resolved to a type

    at IPGUI$2.actionPerformed(IPGUI.java:60)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

所以我实现了监听器和动作执行事件，但我不明白为什么我不能在另一个类中调用该方法？有人能解释我哪里错了吗？提前感谢您的任何意见。

Answer 1

看起来你正在使用Java Swing。不要忘记在类签名的末尾添加“implements ActionListener”。

试试这个：

public class IPGUI extends JFrame implements ActionListener {

...

public IPGUI() {
        setTitle("IP Extractor");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 250, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);

        JPanel panel = new JPanel();
        contentPane.add(panel, BorderLayout.CENTER);
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));

        JButton btnConvertDocuments = new JButton("1. Convert Documents");
        btnConvertDocuments.setAlignmentX(Component.CENTER_ALIGNMENT);
        btnConvertDocuments.setMaximumSize(new Dimension(160, 0));
        btnConvertDocuments.setPreferredSize(new Dimension(0, 50));

        panel.add(btnConvertDocuments);
        //btnConvertDocuments.addActionListener(new ActionListener() {
        //    public void actionPerformed(ActionEvent e) {
        //        //FileConverter fc = new FileConverter();
        //                    //Why wont the above method work?
        //    }
        //});

        btnConvertDocuments.setActionCommand("x");
        btnConvertDocuments.addActionListener(this);

        JSeparator separator_3 = new JSeparator();
        panel.add(separator_3);
}

public void actionPerformed(ActionEvent event) {
    String command = event.getActionCommand();
    if (command.equals("x")) {
        //FileConverter fc = new FileConverter();
    }
}
...

}

Answer 2

您是否在开始时导入了其他课程？

import FileConverter;

Answer 3

检查文件的开头是否有类似

的内容

 import bla.bla.FileConverter;

如果不是，则需要添加它并确保FileConverter类实现是在类传递上。将jar与它一起添加到项目的类路径中，使用什么IDE？

Answer 4

到底是什么？ Eclipse让我感到困惑。我试图在这里遵循每个人的建议，但它没有奏效。但是当我重新启动eclipse时......一切正常。

奇怪：/

感谢大家的投入，我真的很感激！

如何在Java Button（GUI）中调用外部方法

4 个答案: