您可以创建自己的自定义JDialog
在关闭或继续之前检查用户输入等。请参阅此链接:
停止自动关闭对话框
默认情况下,当用户单击 JOptionPane 创建的按钮时,
对话框关闭。但是如果你想先检查用户的回答怎么办
关闭对话框?在这种情况下,您必须实现自己的财产
更改侦听器,以便当用户单击按钮时,对话框会执行
不自动关闭。
这是我做的一个例子:
如果您输入错误/无文本并单击输入,将显示一条验证消息:
如果您点击X关闭对话框或单击“取消”还将显示验证消息:
如果输入了正确的文本(在本例中为“David”)并单击了 Enter,则会显示一条消息,JDialog
已退出:
自定义对话框.java:
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import javax.swing.JDialog;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
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(DISPOSE_ON_CLOSE);
//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);
pack();
}
/**
* This method handles events for the text field.
*/
@Override
public void actionPerformed(ActionEvent e) {
optionPane.setValue(btnString1);
}
/**
* This method reacts to state changes in the option pane.
*/
@Override
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 (magicWord.equals(ucText)) {
JOptionPane.showMessageDialog(this, "Correct answer given");
exit();
} else {
//text was invalid
textField.selectAll();
JOptionPane.showMessageDialog(this,
"Sorry, \"" + typedText + "\" "
+ "isn't a valid response.\n"
+ "Please enter "
+ magicWord + ".",
"Try again",
JOptionPane.ERROR_MESSAGE);
typedText = null;
textField.requestFocusInWindow();
}
} else { //user closed dialog or clicked cancel
JOptionPane.showMessageDialog(this, "It's OK. "
+ "We won't force you to type "
+ magicWord + ".");
typedText = null;
exit();
}
}
}
/**
* This method clears the dialog and hides it.
*/
public void exit() {
dispose();
}
public static void main(String... args) {
//create JDialog and components on EDT
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new CustomDialog(null, "David").setVisible(true);
}
});
}
}