[英]JOptionPane - check user input and prevent from closing until conditions are met
請問有人可以告訴我是否有一種簡便的方法可以防止JOptionPane
在單擊“確定”后關閉,除非滿足用戶輸入字段的條件?
還是我別無選擇,只能使用JFrame
?
到目前為止,我的驗證邏輯。 似乎不起作用,因為由於某種原因,這些按鈕可以一次單擊。
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);
您可以創建自己的Custom JDialog
以在關閉或繼續之前檢查用戶輸入等。 看到這個鏈接:
默認情況下,當用戶單擊JOptionPane創建的按鈕時,對話框關閉。 但是,如果要在關閉對話框之前檢查用戶的答案怎么辦? 在這種情況下,您必須實現自己的屬性更改偵聽器,以便在用戶單擊按鈕時,對話框不會自動關閉。
這是我做的一個例子:
如果鍵入錯誤/沒有文本,然后單擊輸入,將顯示驗證消息:
如果單擊X關閉對話框或單擊“取消”,還將顯示一條驗證消息:
如果輸入正確的文本(在這種情況下為“ David”),然后單擊enter,則會顯示一條消息,並退出JDialog
:
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);
}
});
}
}
關於停止自動對話框關閉的一件事是,它僅在您要防止關閉或驗證然后再關閉時才有幫助...基於該教程中的示例代碼的解決方案,如果無法阻止該對話框進行驗證並保持打開狀態,驗證失敗。
回想起來,我認為我第一次嘗試不起作用的原因可能是因為它使用了JOptionPanel.createDialog()(而不是示例代碼所做的事情)。 也許讓JOptionPanel創建它自己的JDialog,在事件處理的工作方式上設置了一些“后台”依賴項。 無論如何,我現在都有了想要的東西:David Kroucamp的代碼對我來說非常有用。
我發布我的解決方案是因為它與David的處理方式不同,因此它對某些人可能有用。 您會看到很多代碼與他的代碼相同(感謝David)
此類檢查文件是否存在,並允許用戶提供新名稱或取消。 它在用於驗證用戶輸入的構造函數中需要一些args。 驗證為if(!Files.exists(rootPathArg.resolve(input))) { // close the dialog }
class GetPathNameDialog extends JDialog implements ActionListener, PropertyChangeListener {
/**
* contains the users input
*/
private JTextField textField;
/**
* the option pane that holds all fields and controls in this dialog
*/
private JOptionPane optionPane;
/**
* label for the left button that represents "OK"
*/
private String button1Str;
/**
* label for the right button that represents "Cancel"
*/
private String button2Str;
/**
* path containing the named entity to be renamed.
*/
private Path rootPath;
/**
* Creates the reusable dialog.
*/
/**
* Creates the dialog, panel and all GUI components, sets up listeners.
*
* @param rootPath the path where the file or folder we are renaming lives
* @param initialText the initial text to display in the text field (i.e. current name)
* @param title title of the JDialog itself
* @param textFieldWidth number of columns in the JTextField that will contain the file/folder name
* @param promptStr the propmt to display in the panel
* @param button1Str the label for the "OK" button
* @param button2Str the label for the "Cancel" button
*/
public GetPathNameDialog(Path rootPath, String initialText, String title, int textFieldWidth, String promptStr, String button1Str, String button2Str) {
super((Frame) null, true);
// init class variables
this.rootPath = rootPath;
this.button1Str = button1Str;
this.button2Str = button2Str;
setTitle(title);
textField = new JTextField(textFieldWidth);
textField.setText(initialText);
//Create an array of the text and components to be displayed.
Object[] array = {promptStr, textField};
//Create an array specifying the number of dialog buttons
//and their text.
Object[] options = {button1Str, button2Str};
//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 INPUT_VALUE_PROPERTY
textField.addActionListener(this);
// Register an event handler that reacts to option pane state changes.
optionPane.addPropertyChangeListener(this);
// tell this dialog to display close to the current mouse pointer
setLocation(MouseInfo.getPointerInfo().getLocation());
pack();
}
/**
* This method handles events for the text field.
*/
@Override
public void actionPerformed(ActionEvent e) {
// this will fire a INPUT_VALUE_PROPERTY PropertyChangeEvent... takes the user input to the validaton code in the property handler
optionPane.setInputValue(textField.getText());
}
/**
* This method reacts to property changes.
*/
@Override
public void propertyChange(PropertyChangeEvent e) {
String prop = e.getPropertyName();
if (isVisible() && (e.getSource() == optionPane)) {
// the VALUE_PROPERTY is not the same as the INPUT_VALUE_PROPERTY. we make use of the INPUT_VALUE_PROPERTY to carry our data
// but the JOptionPane uses the VALUE_PROPERTY for other stuff
if (JOptionPane.VALUE_PROPERTY.equals(prop)) {
// newValues delivered by VALUE_PROPERTY PropertyChangeEvent can be the actual labels of the button clicked,
// that's sooo counter-intuitive to me, but it's how we know which button got clicked
if (button1Str.equals(e.getNewValue())) {
// "OK" functionality...
// ...this will fire the event that takes the user input to the validation code
optionPane.setInputValue(textField.getText());
} else if (button2Str.equals(e.getNewValue())) {
// "CANCEL" functionality
optionPane.setInputValue(null);
exit();
}
} else if (JOptionPane.INPUT_VALUE_PROPERTY.equals(prop)) {
Object value = optionPane.getInputValue();
// null or empty strings in the text field (ie in the INPUT_VALUE_PROPERTY) are ignored
if (null != value && ((String) value).length() > 0) {
// here is the validation code
if (Files.exists(rootPath.resolve(textField.getText()))) {
// already exists, tell user
JOptionPane.showMessageDialog(this,
"Sorry, " + rootPath.resolve(textField.getText()).toString() + " already exists.\n\n Please enter another name.",
"OK",
JOptionPane.ERROR_MESSAGE);
// Make sure PropertyChangeEvent will fire next time...
// ...PropertyChangeEvents don't fire in setInputValue(newVal)...
// ...if newVal is equal to the current value, but if the user clicks...
// ...button 1 or hits enter in the text field without changing his text,...
// ...we still want to fire another event...
// ...so we reset the property without changing the text in the textField
optionPane.setInputValue(null);
} else {
// does not exist.. we are keeping the users input...
// ... it gets delivered to the user in getInputValue()
exit();
}
}
}
}
}
/**
* returns the users's validated input. Validated means !Files.exists(rootPath.resolve(input)).
*
* @return the text entered by the user, UNINITIALIZED_VALUE if the user X closed, null the user canceled
*/
public Object getInputValue() {
return optionPane.getInputValue();
}
/**
* closes the dialog and triggers the return from setVisible()
*/
public void exit() {
dispose();
}
}
調用它的代碼是:
GetPathNameDialog tempD = new GetPathNameDialog(
someFolderPath,
"theFileNameThatMustBeChanged.txt",
"Change File Name",
50,
"someFolderPath already contains a file named theFileNameThatMustBeChanged.txt." + ".\n\nPlease enter a different file name:",
"Copy the file with the new name", "Do not copy the file");
tempD.setVisible(true);
Object inputObj = tempD.getInputValue();
String input = (inputObj == JOptionPane.UNINITIALIZED_VALUE || null == inputObj ? "" : (String) inputObj);
if (input.length() > 0) {
// we now have a new file name. go ahead and do the copy or rename or whatever...
}
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