jtextfield

问题 I have a JTextField where in the user has to input the data. Its value has to always start with RA and must have exactly 8 digits after it. So, its length will be 10 always. for e.g., RA12345678 . How do I do this in Java? I tried using MaskFormatter and JFormattedTextField but, did not achieve the results. I need to validate the input with length together. 回答1: I'd use a JSpinner for this, and simply prefix RA to the number. E.G. Image Typical Output RA8007006 Code import java.awt.*; import

问题 What I am trying to do is this, when I enter the details it will validate if the textFiled is empty when a button is pressed, if it is empty it will display a message saying that. Then it will move to the next textFile similar to many web based registration forms, what I am trying to find out is why wont the message change? Pasting this code into an ecilpse file and running it should display the simple frame and what I am trying to do. The message displays on the bottom of the frame when the

问题 I'm trying to set up a GUI for a program of mine, and have got it mostly working. However, I would like to be able to create a method that works a lot like Scanner's nextLine(); it waits for the input from my JTextField, and then returns it. It seemed like this question was very similar to mine but did not wait for the user's input. Here is my GUI's current code: package util; import java.awt.Font; import java.awt.BorderLayout; import javax.swing.JFrame; import javax.swing.JTextField; import

问题 I have a JPanel with a bunch of different check boxes and text fields, I have a button that's disabled, and needs to be enabled when specific configurations are setup. What I need is a listener on the the whole JPanel looking for events, whenever anything changes. I believe I need an action listener but I can't find anything to bridge the action Listener with the JPanel JPanel Window = new JPanel(); Window.addActionListener(new ActionListener(){ //Check if configurations is good } I figure I

问题 I want to take only letters as a input in my name field. I have already tried using the matches method but unfortunately something is wrong and the exception is being thrown. Is there any other method of checking the same? import java.awt.BorderLayout; import java.awt.FlowLayout; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.GridLayout; import java.awt.Insets; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*;

问题 I want to take only letters as a input in my name field. I have already tried using the matches method but unfortunately something is wrong and the exception is being thrown. Is there any other method of checking the same? import java.awt.BorderLayout; import java.awt.FlowLayout; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.GridLayout; import java.awt.Insets; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*;

问题 i'd like to create JTextField with input characters limited to someting like "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVXYWZZ0123456789+&@#/%?=~_-|!:,.;" so i tried overriding public class CustomJTextField extends JTextField { String goodchars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVXYWZZ0123456789+&@#/%?=~_-|!:,.;"; //... my class body ...// @Override public void processKeyEvent(KeyEvent ev) { if(c != '\b' && goodchars.indexOf(c) == -1 ) { ev.consume(); return; } else super

问题 I am working on a Java project and need to have a keypress simulate a click on a JTextField. What I'm looking for is the equivalent of the JButton doClick() method. I am trying to have the keypress "enter" perform the exact same function as a click on the JTextField. Not sure what other info to provide. Thanks in advance. 回答1: public void simulateKey(KeyEvent e, Component c) { Field f = KeyEvent.class.getField("focusManagerIsDispatching"); f.setAccessible(true); f.set(e, Boolean.TRUE); c

问题 i have jTextfield and jButton.. how to user can click on jTextfield(mouse can enter/exited on jtextfield), but if user typing something it will not do anything (except backspace that will remove entire text) when user click the button, it will jTextfield.setText("something"); so the only way to give jtextfield text is click the button when there are a text in there (when cursor inside jtextfield) then user typing a backspace, it will remove entire text on jtextfield.. how to do this? forgive

问题 Now finishing my custom menu popup, but the problem is that if I select some text in JTextField and click mouse button to show popup menu, then focus is transferred to popup window, AND selected text before are no longer highlighted. When focus is back to JTextField - selected text become highlighted again. How to make the selected text stay highlighted on focus lost? 回答1: then focus is transferred to popup window, AND selected text before are no longer highlighted. When focus is back to