JDialog总结
1. 使用JOptionPane
JOptionPane, 正如他的名字，他是一个pane，用来作为JDialog的content pane
他提供4种如下static method，去创建显示JDialog。
1.1 showMessageDialog
显示消息消息对话框，可以设置消息内容、标题、消息的样式、图标
1.2 showInputDialog
显示输入对话框，可以设置消息内容、标题、消息的样式、图标、可选择的输入值、初始输入值。
当“可选择的输入值”设置存在时显示下来列表，否则显示JText输入框。
1.3 showConfirmDialog
显示确认对话框, 可以设置消息内容、标题、option样式、消息的样式、图标
1.4 showOptionDialog
显示对话框，可以设置消息内容、标题、option样式、消息的样式、图标、可选择的输入值、初始输入值。
以上三种方法都是补充参数转而调用此方法。当需要改变option JButton上的文字，需要直接调用这个方法
这些static method会创建一个JOptionPane，然后创建JDialog，并将其content pane设置成前面创建的
JOptionPane。当此JOptionPane的value改变时，其property change listener会调用此JDialog的setVisual method。
消息的样式有ERROR_MESSAGE、INFORMATION_MESSAGE、WARNING_MESSAGE、QUESTION_MESSAGE、PLAIN_MESSAGE。
除了使用JOptionPane提供的四类static method。当功能不能满足时，比如屏保窗口修饰的关闭按钮功能、对输入的文本进行验证，可以手动创建
JOptionPane和JDialog，进行相应设置后将新建的JOptionPane作为新建的JDialog的content pane。最后调用新建的JDialog的pack和setVisual method去显示对话框。以下是样例，代码来源于Java指南
样例一：屏保窗口修饰的关闭按钮功能
final JOptionPane optionPane = new JOptionPane(
"The only way to close this dialog is by/npressing one of the following buttons./nDo you understand?",
JOptionPane.QUESTION_MESSAGE,
JOptionPane.YES_NO_OPTION);
// You can't use pane.createDialog() because that
// method sets up the JDialog with a property change
// listener that automatically closes the window
// when a button is clicked.
final JDialog dialog = new JDialog(frame, "Click a button", true);
dialog.setContentPane( optionPane );
dialog.setDefaultCloseOperation( JDialog.DO_NOTHING_ON_CLOSE );
dialog.addWindowListener( new WindowAdapter() {
@Override
public void windowClosing(WindowEvent we) {
setLabel("Thwarted user attempt to close window.");
}
});
optionPane.addPropertyChangeListener(
new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
String prop = e.getPropertyName();
if ( dialog.isVisible()
&& e.getSource()==optionPane
&& JOptionPane.VALUE_PROPERTY.equals(prop) ) {
//If you were going to check something
//before closing the window, you'd do
//it here.
dialog.setVisible(false);
dialog.dispose();
}
}
});
dialog.pack();
dialog.setLocationRelativeTo( frame );
dialog.setVisible( true );
int value = ((Integer)optionPane.getValue()).intValue();
if (value == JOptionPane.YES_OPTION) {
// Good
} else if (value == JOptionPane.NO_OPTION) {
// Try using the window decorations to close the non-auto-closing dialog. You can't!
} else {
// Window unavoidably closed (ESC?).
}
样例二：对输入的文本进行验证
定义JDialog
package components;
import javax.swing.JOptionPane;
import javax.swing.JDialog;
import javax.swing.JTextField;
import java.beans.*; //property change stuff
import java.awt.*;
import java.awt.event.*;
class CustomDialog extends JDialog implements ActionListener, PropertyChangeListener {
private String typedText = null;
private JTextField textField;
private String magicWord;
private JOptionPane optionPane;
private String btnString1 = "Enter";
private String btnString2 = "Cancel";
/**
* 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 CustomDialog(Frame aFrame, String aWord) {
super(aFrame, true);
magicWord = aWord.toUpperCase();
setTitle("Quiz");
textField = new JTextField(10);
//Create an array of the text and components to be displayed.
String msgString1 = "What was Dr. SEUSS's real last name?";
String msgString2 = "(The answer is /"" + magicWord + "/".)";
Object[] array = {msgString1, msgString2, 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.QUESTION_MESSAGE, JOptionPane.YES_NO_OPTION, null,
options, options[0]);
//Make this dialog display it.
setContentPane( optionPane );
//Handle window closing correctly.
setDefaultCloseOperation( DO_NOTHING_ON_CLOSE );
addWindowListener( new WindowAdapter() {
@Override
public void windowClosing(WindowEvent we) {
/*
* Instead of directly closing the window,
* we're going to change the JOptionPane's
* value property.
*/
optionPane.setValue( JOptionPane.CLOSED_OPTION );
}
});
//Ensure the text field always gets the first focus.
addComponentListener(new ComponentAdapter() {
@Override
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);
}
/** This method reacts to state changes in the option pane. */
public void propertyChange(PropertyChangeEvent e) {
String propName = e.getPropertyName();
if ( isVisible()
&& e.getSource()==optionPane
&& (JOptionPane.VALUE_PROPERTY.equals(propName) || JOptionPane.INPUT_VALUE_PROPERTY.equals(propName))) {
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();
if ( magicWord.equalsIgnoreCase(typedText) ) {
//we're done; clear and dismiss the dialog
clearAndHide();
} else {
//text was invalid
textField.selectAll();
JOptionPane.showMessageDialog( this, "Sorry, /"" + typedText + "/" isn't a valid response./nPlease enter " + magicWord + ".", "Try again",
JOptionPane.ERROR_MESSAGE );
typedText = null;
textField.requestFocusInWindow();
}
} else { //user closed dialog or clicked cancel
// It's OK. We won't force you to type magicWord;
typedText = null;
clearAndHide();
}
}
}
/** This method clears the dialog and hides it. */
public void clearAndHide() {
textField.setText(null);
setVisible(false);
dispose();
}
}
调用
customDialog = new CustomDialog(frame, "geisel", this);
customDialog.pack();
customDialog.setLocationRelativeTo(frame);
customDialog.setVisible(true);
String s = customDialog.getValidatedText();
if (s != null) {
//The text is valid.
}
2. 使用JDialog
手动创建JDialog及其content pane, 然后调用其pack和setVisual method去显示对话框。