Java Swing –保持对话框窗口打开

超、凢脫俗 2023-02-15 05:16 10阅读 0赞

在我们的应用程序中实现对话框最常见*（*最*简单）的*方法是`JOptionPane`类。 在本文中，我们将讨论如何“覆盖”当用户单击`JOptionPane`创建的按钮时，关闭对话框窗口的`JOptionPane`的默认行为。

在继续进行示例之前，我们需要知道的是，当我们在应用程序中使用`JOptionPane` ，真正在后台运行的是模式`JDialog` 。 `JOptionPane`是一个容器，可以自动创建`JDialog`并将其自身添加到其`content pane` 。

## 1.基本示例 ##

在此示例中，我们阻止对话框窗口自动关闭，而是通过实现`PropertyChange`侦听器自行处理它。 下面的示例是在代码中实现此机制的绝对基础，因为不处理用户交互或输入检查。

KeepDialogUp.java

package com.mkyong.stayup;
    
    import java.beans.PropertyChangeEvent;
    import java.beans.PropertyChangeListener;
    
    import javax.swing.ImageIcon;
    import javax.swing.JDialog;
    import javax.swing.JFrame;
    import javax.swing.JOptionPane;
    
    public class KeepDialogUp {
    
        public static void main(String[] args) {
            JFrame frame = new JFrame();
            ImageIcon icon = new ImageIcon("src/images/turtle64.png");
    
            Object[] options = {"I DO LOVE TURTLES"};
            JOptionPane jop = new JOptionPane("Admit your love for turtles\nor you shall not pass!!"
                    , JOptionPane.ERROR_MESSAGE, 0, icon, options, options[0]);
    
            JDialog dialog = new JDialog(frame, "You LOVE turtles", true);
            dialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
            dialog.setContentPane(jop);
    
            jop.addPropertyChangeListener(new PropertyChangeListener() {
                @Override
                public void propertyChange(PropertyChangeEvent evt) {
                    if (JOptionPane.VALUE_PROPERTY.equals(evt.getPropertyName())) {
                        dialog.dispose();
                        JOptionPane.showMessageDialog(null, "Good for you >:P");
                        System.exit(0);
                    }
    
                }
            });
            dialog.pack();
            dialog.setLocationRelativeTo(frame);
            dialog.setVisible(true);
        }
    }

输出：

![swing-keep-dialog-up-1][]![swing-keep-dialog-up-1][swing-keep-dialog-up-1 1]

如果用户尝试关闭窗口，则什么也不会发生。 如果用户单击“我喜欢龟甲”按钮，程序将显示以下对话框，然后退出。

![swing-keep-dialog-up-2][]![swing-keep-dialog-up-2][swing-keep-dialog-up-2 1]

## 2.侦听器示例 ##

现在让我们为前面的示例添加趣味。 我们将添加一个`windowListener`来处理用户关闭对话框的尝试，并在`propertyChangeListener`检查用户的输入。

KeepDialogUpExtended.java

package com.mkyong.stayup;
    
    import java.awt.event.WindowAdapter;
    import java.awt.event.WindowEvent;
    import java.beans.PropertyChangeEvent;
    import java.beans.PropertyChangeListener;
    
    import javax.swing.ImageIcon;
    import javax.swing.JDialog;
    import javax.swing.JFrame;
    import javax.swing.JOptionPane;
    
    public class KeepDialogUpExtended {
    
        public static void main(String[] args) {
            JFrame frame = new JFrame();
            ImageIcon icon = new ImageIcon("src/images/turtle64.png");
    
            Object[] options = {"I DO LOVE TURTLES"};
            JOptionPane jop = new JOptionPane("Admit your love for turtles\nor you shall not pass!!",
                    JOptionPane.ERROR_MESSAGE, 0, icon, options, options[0]);
    
            JDialog dialog = new JDialog(frame, "You LOVE turtles", true);
            dialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
            dialog.setContentPane(jop);
    
            dialog.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent evt) {
                    JOptionPane.showMessageDialog(frame, "YOU SHALL NOT PASS", "!!",
                            JOptionPane.ERROR_MESSAGE);
                }
            });
    
            jop.addPropertyChangeListener(new PropertyChangeListener() {
                @Override
                public void propertyChange(PropertyChangeEvent evt) {
                    if (JOptionPane.VALUE_PROPERTY.equals(evt.getPropertyName())) {
                        if (jop.getValue().equals(options[0])) {
                            dialog.dispose();
                            JOptionPane.showMessageDialog(null, "Good for you >:P");
                            System.exit(0);
                        } else {
                            JOptionPane.showMessageDialog(frame, "There is no\n>> ESC <<",
                                    "You little shenanigan...", JOptionPane.ERROR_MESSAGE);
                        }
                    }
    
                }
            });
            dialog.pack();
            dialog.setLocationRelativeTo(frame);
            dialog.setVisible(true);
        }
    
    }

输出：

![swing-keep-dialog-up-1][]![swing-keep-dialog-up-1][swing-keep-dialog-up-1 1]

如果用户尝试关闭窗口：

![swing-keep-dialog-up-3][]![swing-keep-dialog-up-3][swing-keep-dialog-up-3 1]

如果用户按下Esc键：

![swing-keep-dialog-up-4][]![swing-keep-dialog-up-4][swing-keep-dialog-up-4 1]

这几乎总结了这个机制。 有人可能会争辩说，以传统方式处理用户输入来检查`JOptionPane`的返回值在资源上更有效。 也许吧，也许不是； 根据代码的其余部分，此机制可能是缺少的部分。 但可以肯定的是，您越了解，您做出正确选择的机会就越大。

## 参考文献 ##

1.  [停止自动关闭对话框][Link 1]
2.  [类对话框– Java 8 API][Java 8 API]
3.  [JOptionPane类– Java 8 API][JOptionPane_ Java 8 API]

标签： [对话框][Link 2] [JOptionPane][] [摇摆][Link 3]

> 翻译自: [https://mkyong.com/swing/java-swing-keep-dialog-window-up/][https_mkyong.com_swing_java-swing-keep-dialog-window-up]

[swing-keep-dialog-up-1]: http://imgconvert.csdnimg.cn/aHR0cDovL3d3dy5ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE3LzAxL3N3aW5nLWtlZXAtZGlhbG9nLXVwLTEucG5n?x-oss-process=image/format,png
[swing-keep-dialog-up-1 1]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly93d3cubWt5b25nLmNvbS93cC1jb250ZW50L3VwbG9hZHMvMjAxNy8wMS9zd2luZy1rZWVwLWRpYWxvZy11cC0xLnBuZw?x-oss-process=image/format,png
[swing-keep-dialog-up-2]: http://imgconvert.csdnimg.cn/aHR0cDovL3d3dy5ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE3LzAxL3N3aW5nLWtlZXAtZGlhbG9nLXVwLTIucG5n?x-oss-process=image/format,png
[swing-keep-dialog-up-2 1]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly93d3cubWt5b25nLmNvbS93cC1jb250ZW50L3VwbG9hZHMvMjAxNy8wMS9zd2luZy1rZWVwLWRpYWxvZy11cC0yLnBuZw?x-oss-process=image/format,png
[swing-keep-dialog-up-3]: http://imgconvert.csdnimg.cn/aHR0cDovL3d3dy5ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE3LzAxL3N3aW5nLWtlZXAtZGlhbG9nLXVwLTMucG5n?x-oss-process=image/format,png
[swing-keep-dialog-up-3 1]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly93d3cubWt5b25nLmNvbS93cC1jb250ZW50L3VwbG9hZHMvMjAxNy8wMS9zd2luZy1rZWVwLWRpYWxvZy11cC0zLnBuZw?x-oss-process=image/format,png
[swing-keep-dialog-up-4]: http://imgconvert.csdnimg.cn/aHR0cDovL3d3dy5ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE3LzAxL3N3aW5nLWtlZXAtZGlhbG9nLXVwLTQucG5n?x-oss-process=image/format,png
[swing-keep-dialog-up-4 1]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly93d3cubWt5b25nLmNvbS93cC1jb250ZW50L3VwbG9hZHMvMjAxNy8wMS9zd2luZy1rZWVwLWRpYWxvZy11cC00LnBuZw?x-oss-process=image/format,png
[Link 1]: http://docs.oracle.com/javase/tutorial/uiswing/components/dialog.html#stayup
[Java 8 API]: https://docs.oracle.com/javase/8/docs/api/java/awt/Dialog.html
[JOptionPane_ Java 8 API]: https://docs.oracle.com/javase/8/docs/api/javax/swing/JOptionPane.html
[Link 2]: https://mkyong.com/tag/dialog/
[JOptionPane]: https://mkyong.com/tag/joptionpane/
[Link 3]: https://mkyong.com/tag/swing/
[https_mkyong.com_swing_java-swing-keep-dialog-window-up]: https://mkyong.com/swing/java-swing-keep-dialog-window-up/