JOptionPane - 检查用户输入并防止关闭，直到满足条件 [英] JOptionPane - check user input and prevent from closing until conditions are met
问题描述
除非满足用户输入字段的条件，否则有人可以告诉我是否有一种方便的方法可以阻止 JOptionPane 关闭，除非满足用户输入字段的条件？
Please can someone tell me if there is a convenient way of prevent JOptionPane from closing upon clicking OK unless the conditions for user input fields are met?
或者我别无选择，只能使用 JFrame ？
Or do I have no choice but to use JFrame?
我的验证逻辑到目前为止。似乎没有用，因为按钮因某种原因一次性可点击...
My validation logic so far. Doesn't seem to work because the buttons are one-time clickable to some reason...
final JDialog dialog3 = new JDialog(OmniGUI.getFrame(), "Create new Node - id:" + newNodeID);
dialog3.setContentPane(theOPane);
dialog3.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
theOPane.addPropertyChangeListener(new PropertyChangeListener(){
public void propertyChange(PropertyChangeEvent e) {
if(e.getSource() == theOPane){
String val = (String) ((JOptionPane) e.getSource()).getValue();
if(val=="Create"){
System.out.println("Checking content");
if(!valid){
System.out.println("closing the window");
dialog3.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dialog3.removeAll();
dialog3.dispatchEvent(new WindowEvent(dialog3, WindowEvent.WINDOW_CLOSING));
}
}
}
}
});
dialog3.setLocation(p);
dialog3.pack();
dialog3.setVisible(true);
推荐答案
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。看到这个链接：
You can create your own Custom JDialog to check user input etc before closing or moving on. See this link:
默认情况下，当用户点击JOptionPane创建的按钮时，
对话框关闭。但是，如果您想在
关闭对话框之前检查用户的答案呢？在这种情况下，您必须实现自己的属性
更改侦听器，以便当用户单击按钮时，对话框会执行
不会自动关闭。
By default, when the user clicks a JOptionPane-created button, the dialog closes. But what if you want to check the user's answer before closing the dialog? In this case, you must implement your own property change listener so that when the user clicks a button, the dialog does not automatically close.
这是我做的一个例子：
如果输入错误/无文本并单击Enter，将显示验证消息：
If you type wrong/no text and click Enter a validation message will be displayed:
如果您单击 X 以关闭对话框或单击取消，则还会显示验证消息：
If you click X to close Dialog or click Cancel a validation message will be shown also:
如果输入了正确的文字（在这个案例大卫）并点击输入显示一条消息并退出 JDialog ：
If correct text is entered (in this case "David") and enter is clicked a message is shown and JDialog is exited:
CustomDialog.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);
}
});
}
}
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