如何通过关闭JFrame直接关闭JOptionPane？

Question

我是新来学习javax.swing并且有疑问.

我有一个JFrame,其defaultCloseOperation设置为EXIT_ON_CLOSE.我有另一种成分-一JOptionPane- 过了JFrame.我想要发生的是,即使焦点在JOptionPane消息对话框上,我也希望程序在单击窗口x上的按钮时终止JFrame.

所以,确切地说,我希望JFrame在不关闭JOptionPane消息对话框的情况下引起焦点,以便我可以关闭JFrame窗口,从而使程序终止.

这是我的代码:

import javax.swing.*;

public class JJSS {
    public JFrame jf;

    public JJSS(){
        jf = new JFrame();

        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setSize(400, 400);
        jf.setVisible(true);
    }

    public void runMethod(){
        String str = JOptionPane.showInputDialog(jf, "Enter something...");
        str = String.valueOf(new StringBuffer(str).reverse());
        JOptionPane.showMessageDialog(jf, "Reversed: "+str, "Output", JOptionPane.PLAIN_MESSAGE);
    }

    public static void main(String[] args){
        new JJSS().runMethod();
        System.exit(0);
    }

}

使用当前代码,当我单击窗口的关闭按钮(x)时没有任何反应JFrame.

当JOptionPane对话框仍在其上时,如何将焦点放在JFrame窗口上,并通过关闭JFrame窗口来终止程序？

Answer 1

对话模态是关键

您无法使用普通的JOptionPane或任何模式对话框执行此操作,因为模式会阻止用户在显示对话框时与GUI的其他组件交互.如果创建非模态对话框,只能使用JOptionPane静态工厂方法创建JOptionPane,而不是使用JOptionPane构造函数以非传统方式创建JOptionPane,则只能使其工作 - 检查JOptionPane API如何做到这一点.

例如:

import java.awt.Dialog.ModalityType;
import java.awt.Dimension;
import java.awt.event.ActionEvent;

import javax.swing.*;

public class NonModalJOptionPane {

    private static void createAndShowGui() {
        JPanel panel = new JPanel();
        panel.setPreferredSize(new Dimension(400, 300));

        final JFrame frame = new JFrame("NonModalJOptionPane");

        panel.add(new JButton(new AbstractAction("Push Me") {
            @Override
            public void actionPerformed(ActionEvent e) {
                JOptionPane optionPane = new JOptionPane("My Message", JOptionPane.PLAIN_MESSAGE);
                JDialog dialog = optionPane.createDialog(frame, "My Option");
                dialog.setModalityType(ModalityType.MODELESS); // **** key ***
                dialog.setVisible(true);
            }
        }));

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(panel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}

这段代码的关键在于:

// create the JOptionPane using one of its constructors
JOptionPane optionPane = new JOptionPane("My Message", JOptionPane.PLAIN_MESSAGE);

// create a JDialog from it, tying it to the parent JFrame, here called "frame"
JDialog dialog = optionPane.createDialog(frame, "My Option");

// setting the modality type so that it is **not** modal
dialog.setModalityType(ModalityType.MODELESS); // **** key ***

// and then displaying it
dialog.setVisible(true);

我通过其构造函数创建JOptionPane,而不是通过静态方法,我创建一个JDialog并将其设置为MODELESS,然后显示它.

另一个可行的选择是创建自己的JDialog,确保将其设置为非模态.

例如,您可以将以下代码添加到上面的代码中:

panel.add(new JButton(new AbstractAction("Push Me 2 -- Using Dialog") {
    @Override
    public void actionPerformed(ActionEvent e) {
        // button that when pressed, closes the JDialog that holds it
        // similar to a JOptionPane's OK button
        JButton disposeWinBtn = new JButton(new DisposeWindowAction("OK", KeyEvent.VK_O));

        // create a bunch of JPanels, add components to them, ...
        JPanel bottomPanel = new JPanel();
        bottomPanel.add(disposeWinBtn);

        JLabel msgLabel = new JLabel("My Message");
        JPanel msgPanel = new JPanel();
        msgPanel.add(msgLabel);

        JPanel panel = new JPanel(new BorderLayout());
        panel.add(msgPanel, BorderLayout.CENTER);
        panel.add(bottomPanel, BorderLayout.PAGE_END);

        // create a JDialog whose parent component is the main JFrame
        // and make sure that it is *****non-modal ***** <===== this is KEY *****
        JDialog dialog = new JDialog(frame, "Dialog", ModalityType.MODELESS);
        dialog.add(panel);  // add the JPanel, panel, created above, with components
        dialog.pack();  // have layout managers do their thing
        dialog.setLocationRelativeTo(frame); // center it over the main JFrame
        dialog.setVisible(true);  // and display it
    }
}));

就在第一个按钮添加的位置.您还需要DisposeWindowAction类,它允许按钮关闭并处理显示它的窗口(这里是一个JDialog窗口):

import java.awt.Component;
import java.awt.Window;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.SwingUtilities;

@SuppressWarnings("serial")
public class DisposeWindowAction extends AbstractAction {
    public DisposeWindowAction(String name, int mnemonic) {
        super(name);
        putValue(MNEMONIC_KEY, mnemonic);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        Component component = (Component) e.getSource();
        if (component == null) {
            return;
        }
        Window win = SwingUtilities.getWindowAncestor(component);
        if (win == null) {
            return;
        }
        win.dispose();
    }
}