How do you handle a Cancel button in JOptionPane?
If the user clicks “cancel”, the response will be null. If they click “ok” without entering any text the response will be the empty string. But your code does not handle a situation, if you your input is empty and you hit OK button.
What does JOptionPane showInputDialog do?
JOptionPane. showMessageDialog(null, “alert”, “alert”, JOptionPane. ERROR_MESSAGE);…Class JOptionPane.
| Method Name | Description |
|---|---|
| showInputDialog | Prompt for some input. |
| showMessageDialog | Tell the user about something that has happened. |
| showOptionDialog | The Grand Unification of the above three. |
What does showInputDialog return?
showInputDialog() will return the string the user has entered if the user hits ok, and returns null otherwise. Therefore, you can just check to see if the resultant string is null .
What does showInputDialog always return?
showInputDialog always returns null – Stack Overflow.
What is the return type from invoking JOptionPane showInputDialog () method?
JOptionPane. showInputDialog() will return the string the user has entered if the user hits ok, and returns null otherwise.
How do I close a JFrame with a button?
How to Close a JFrame in Java by a Button
- btn. addActionListener(e -> {
- frame. dispose();
- });
What is the return type from invoking JOptionPane Showconfirmdialog () method?
It will return an int which represents which button was pressed.
How do you exit a button in Java?
If you want a JButton that closes the application, you would create the button: JButton Button = new JButton(“Close”);
How do you add a button in JOptionPane?
JPanel panel = new JPanel(); JComboBox optionsBox = new JComboBox(); panel. add(optionsBox); for(ICarOption option : spec. getCarOptions(category)){ optionsBox. addItem(option); } Object[] options = { “Select option”, “Skip”, “Cancel” }; int selected = JOptionPane.
How do I close a button in JFrame?
Which method is called when the user clicks out of the window frame?
The class PopupWindow has an action() method that is called when the user clicks one of the buttons. When the user clicks on a button, action() prints a message and hides the window.
Does joptionpane return NULL if the user presses the Cancel button?
This is the best answer. JOptionPane.showInputDialog returns null if the user presses the cancel button, regardless of what has been entered in the text box. As a side note, I think mispelling JOptionPane (on line 11) should raise exceptions needlessly.
How to detect joptoinpane in showmessagedialog?
The showMessageDialog, shouldn’t show two buttons, so something is amiss with either your code or your interpretation of it. Regardless, if you want to give the user an choice and want to detect that choice, don’t use a showMessageDialog but rather a showConfirmDialog, and get the int returned and test it to see if it is JOptoinPane.OK_OPTION.
What happens when the user presses the Cancel button?
Look at the answer below, by A-SM. The input dialog will return null if the user presses the cancel button, regardless of what they have entered.
How to break a loop in joptionpane?
After you have shown the OptionDialog you must use a break statement, in order to break the loop. JOptionPane doesn’t know about your loop.