JOptionPane上的ActionListener

Question

我正在关注有关如何创建自定义对话框的Oracle教程：http
:
//docs.oracle.com/javase/tutorial/uiswing/components/dialog.html

我有两个按钮：“保存对象”和“删除对象”，单击它们应执行一段代码。不幸的是，我似乎无法向JOptionPane按钮添加任何ActionListener，因此单击它们时什么也没有发生。

谁能帮我告诉我该怎么做？这是到目前为止对话框的类：

class InputDialogBox extends JDialog implements ActionListener, PropertyChangeListener {
    private String typedText = null;
    private JTextField textField;

    private JOptionPane optionPane;

    private String btnString1 = "Save Object";
    private String btnString2 = "Delete Object";

    /**
     * Returns null if the typed string was invalid;
     * otherwise, returns the string as the user entered it.
     */
    public String getValidatedText() {
        return typedText;
    }

    /** Creates the reusable dialog. */
    public InputDialogBox(Frame aFrame, int x, int y) {
        super(aFrame, true);

        setTitle("New Object");

        textField = new JTextField(10);

        //Create an array of the text and components to be displayed.
        String msgString1 = "Object label:";

        Object[] array = {msgString1, textField};

        //Create an array specifying the number of dialog buttons
        //and their text.
        Object[] options = {btnString1, btnString2};

        //Create the JOptionPane.
        optionPane = new JOptionPane(array,
                JOptionPane.PLAIN_MESSAGE,
                JOptionPane.YES_NO_OPTION,
                null,
                options,
                options[0]);


        setSize(new Dimension(300,250));
        setLocation(x, y);

        //Make this dialog display it.
        setContentPane(optionPane);
        setVisible(true);

        //Handle window closing correctly.
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                /*
                 * Instead of directly closing the window,
                 * we're going to change the JOptionPane's
                 * value property.
                 */
                optionPane.setValue(new Integer(
                        JOptionPane.CLOSED_OPTION));
            }
        });

        //Ensure the text field always gets the first focus.
        addComponentListener(new ComponentAdapter() {
            public void componentShown(ComponentEvent ce) {
                textField.requestFocusInWindow();
            }
        });

        //Register an event handler that puts the text into the option pane.
        textField.addActionListener(this);

        //Register an event handler that reacts to option pane state changes.
        optionPane.addPropertyChangeListener(this);
    }

    /** This method handles events for the text field. */
    public void actionPerformed(ActionEvent e) {
        optionPane.setValue(btnString1);
        System.out.println(e.getActionCommand());
    }

    /** This method reacts to state changes in the option pane. */
    public void propertyChange(PropertyChangeEvent e) {
        String prop = e.getPropertyName();

        if (isVisible()
         && (e.getSource() == optionPane)
         && (JOptionPane.VALUE_PROPERTY.equals(prop) ||
             JOptionPane.INPUT_VALUE_PROPERTY.equals(prop))) {
            Object value = optionPane.getValue();

            if (value == JOptionPane.UNINITIALIZED_VALUE) {
                //ignore reset
                return;
            }

            //Reset the JOptionPane's value.
            //If you don't do this, then if the user
            //presses the same button next time, no
            //property change event will be fired.
            optionPane.setValue(JOptionPane.UNINITIALIZED_VALUE);
            if (btnString1.equals(value)) {
                    typedText = textField.getText();
                String ucText = typedText.toUpperCase();
                if (ucText != null ) {
                    //we're done; clear and dismiss the dialog
                    clearAndHide();
                } else {
                    //text was invalid
                    textField.selectAll();
                    JOptionPane.showMessageDialog(
                                InputDialogBox.this,
                                    "Please enter a label",
                                    "Try again",
                                    JOptionPane.ERROR_MESSAGE);
                    typedText = null;
                    textField.requestFocusInWindow();
                }
            } else { //user closed dialog or clicked delete
               // Delete the object ...

                typedText = null;
                clearAndHide();
            }
        }
    }

    /** This method clears the dialog and hides it. */
    public void clearAndHide() {
        textField.setText(null);
        setVisible(false);
    }

Answer 1

我认为您错过了重点JOptionPane。它具有显示自己的对话框的功能…

public class TestOptionPane02 {

    public static void main(String[] args) {
        new TestOptionPane02();
    }

    public TestOptionPane02() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JTextField textField = new JTextField(10);

                String btnString1 = "Save Object";
                String btnString2 = "Delete Object";

                //Create an array of the text and components to be displayed.
                String msgString1 = "Object label:";
                Object[] array = {msgString1, textField};
                //Create an array specifying the number of dialog buttons
                //and their text.
                Object[] options = {btnString1, btnString2};

                int result = JOptionPane.showOptionDialog(null, array, "", JOptionPane.YES_NO_OPTION, JOptionPane.PLAIN_MESSAGE, "New Object", options, options[0]);
                switch (result) {
                    case 0:
                        System.out.println("Save me");
                        break;
                    case 1:
                        System.out.println("Delete me");
                        break;
                }
            }
        });
    }
}

要手动执行此操作，您将需要做更多的工作。

首先，您将不得不侦听面板的属性更改事件，寻找的更改，JOptionPane.VALUE_PROPERTY并忽略JOptionPane.UNINITIALIZED_VALUE…的任何值。

一旦检测到更改，就需要处理对话框。

您将需要提取通过JOptionPane#getValue方法选择的值，该方法返回Object。您将不得不自己打断该值的含义…

不用说，JOptionPane.showXxxDialog方法可以为您完成所有这些工作…

现在，如果您担心必须完成对话框的所有设置，那么我将编写一个实用程序方法，该方法可以完全完成对话框或采用必需的参数…但这就是我

更新

不知道为什么我不早想到…

而不是传递数组String作为options参数，而是传递的数组JButton。这样，您可以附加自己的侦听器。

options-一组对象，指示用户可以做出的可能选择； 如果对象是组件，则可以正确渲染它们
；非字符串对象使用其toString方法呈现；如果此参数为null，则选项由外观决定