java - 如何实现模态对话框的效果

Question

我有一个将启动另一个窗口的父窗口。当子窗口启动时，我希望它显示为模态对话框。

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

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;


public class ModalDialogTest {
    public void createUI(){
        JFrame frame = new JFrame("Test");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        JPanel mainPanel = new JPanel();

        mainPanel.setBorder(BorderFactory.createEmptyBorder(200, 200, 200, 200));
        JButton openButton = new JButton("Open a frame");
        openButton.addActionListener(new ActionListener() { 
            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                AnotherWindow anotherWindow = new AnotherWindow();
                anotherWindow.createUI();
            }
        });
        mainPanel.add(openButton,BorderLayout.CENTER);

        frame.add(mainPanel,BorderLayout.CENTER);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        ModalDialogTest modelDialogTest = new ModalDialogTest();
        modelDialogTest.createUI();
    }

    class AnotherWindow{
        public void createUI(){
            JFrame frame = new JFrame("Dialog");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setResizable(false);
            JPanel mainPanel = new JPanel();

            mainPanel.setBorder(BorderFactory.createEmptyBorder(100, 100, 100, 100));

            JLabel label = new JLabel("I want to be a modal dialog");
            mainPanel.add(label,BorderLayout.CENTER);

            frame.add(mainPanel,BorderLayout.CENTER);
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        }
    }
}

上面的demo描述了我的app的流程，架构是一样的，那怎么解决呢？

Answer 1

您不能设置JFrame 的模态；第二个窗口必须是 JDialog。因此，将第二个 JFrame 更改为 JDialog 并使用方法 setModalityType()在上面。