JFrame在单独的类中，那么ActionListener呢？

Question

我试图将我的Swing GUI与实际代码分开。简而言之，我希望用户启动一个过程（基于用户的选择）；在这种情况下，将不再需要JFrame。

我不知道的是如何与Main.class共享来自GUI.class的用户选择。

您对我有什么建议吗？

这是我的代码：

public class Main {
  public static void main(String[] args) {
    // Show GUI
    java.awt.EventQueue.invokeLater(new Runnable() {
      public void run() {
        GUI gui = new GUI(templates);
        gui.setVisible(true);
      }
    });

    // Kick off a process based on the user's selection
  }
}

public class GUI extends JFrame {
  private static final long serialVersionUID = 1L;

  public GUI(Object[] objects) {
    setTitle("GUI");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 350, 100);
    setLocationRelativeTo(null);

    JPanel cp = new JPanel();
    cp.setBorder(new EmptyBorder(10, 10, 10, 10));
    setContentPane(cp);

    JLabel lbl = new JLabel("Selection:");
    cp.add(lbl);

    final JComboBox<String> comboBox = new JComboBox<String>(new String[] { "One", "Two", "Three" });
    comboBox.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        setVisible(false);
        dispose();
        // Share the selected item with Main.class
      }
    });
    cp.add(comboBox);
  }
}

Answer 1

一个很好的方法是使用 Callback 机制。

遵循的步骤：

• 创建一个回调接口

  interface Callback {
  void execute(Object result);
  

  }

• GUI类将实现Callback接口，但不提供任何实现

• 制作GUI类abstract

  abstract class GUI extends JFrame implements Callback
  

• 现在创建一个GUI类的对象，提供Callback接口的实际实现

• 在这里你可以使用匿名类

  GUI gui = new GUI() {
  
  @Override
  public void execute(Object result) {
      System.out.println("You have selected " + result);
  }
  

  };

• 您可以通过的execute()方法传递任何内容Callback。

  comboBox.addActionListener(new ActionListener() {
  @Override
  public void actionPerformed(ActionEvent e) {
      setVisible(false);
      dispose();
      // Share the selected item with Main.class
      // Callback
      execute(comboBox.getSelectedItem());
  }
  

  });

在这里，Main类负责捕获Callback由GUI类指示的响应。

这是代码：

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;

public class Main {
    public static void main(String[] args) {
        // Show GUI
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                GUI gui = new GUI() {

                    @Override
                    public void execute(Object result) {
                        System.out.println("You have selected " + result);
                    }

                };
                gui.setVisible(true);
            }
        });

        // Kick off a process based on the user's selection
    }
}

interface Callback {
    void execute(Object result);
}

abstract class GUI extends JFrame implements Callback {
    private static final long serialVersionUID = 1L;

    public GUI() {
        setTitle("GUI");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 350, 100);
        setLocationRelativeTo(null);

        JPanel cp = new JPanel();
        cp.setBorder(new EmptyBorder(10, 10, 10, 10));
        setContentPane(cp);

        JLabel lbl = new JLabel("Selection:");
        cp.add(lbl);

        final JComboBox comboBox = new JComboBox(new String[] { "One", "Two", "Three" });
        comboBox.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                setVisible(false);
                dispose();
                // Share the selected item with Main.class
                execute(comboBox.getSelectedItem());
            }
        });
        cp.add(comboBox);
    }

}