JOptionPane - 检查用户输入并防止在满足条件之前关闭 [英] JOptionPane - check user input and prevent from closing until conditions are met
问题描述
请有人告诉我，除非满足用户输入字段的条件，否则是否有一种方便的方法可以防止 JOptionPane 在单击确定"时关闭?
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?
到目前为止我的验证逻辑.似乎不起作用，因为按钮出于某种原因可以一次性点击...
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 以在关闭或继续之前检查用户输入等.请参阅此链接:
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，当用户单击 JOptionPane 创建的按钮时，对话框关闭.但是如果你想之前检查用户的答案怎么办关闭对话框?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:
如果您输入错误/无文本并单击输入"，则会显示验证消息:
If you type wrong/no text and click Enter a validation message will be displayed:
如果您单击 X 关闭对话框或单击取消，也会显示一条验证消息:
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本(在本例中为David")并单击 Enter，则会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.
"
+ "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);
}
});
}
}
这篇关于JOptionPane - 检查用户输入并防止在满足条件之前关闭的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
