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,单击它们应该执行一段代码。不幸的是,我似乎无法将任何 ActionListener 添加到 JOptionPane 按钮,所以当它们被点击时,什么也没有发生。
谁能帮我告诉我该怎么做?到目前为止,这是我为对话框设置的类:
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);
}