如何实现文档侦听器 [英] How to implement documentlistener
本文介绍了如何实现文档侦听器的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我创建了一些我想从中使用用户输入的文本字段.我已经读过我应该使用文档侦听器，但是我认为在正确的位置实现它有些困难.
I have created some textfields from which i want to use the user-input. I have read that i should use a documentlistener, but i have some difficulty implementing it the right place i think.
在代码中，我试图将其实现到文本字段tf1.输入的即时消息应该被解析为双精度，以便我可以对其进行一些数学计算.
In the code i am trying to implement it to the textfield tf1. The input im should get is to be parsed to a double so i can do some math calculation on it.
这是我尝试实现它的代码.
Here is my code where i try to implement it.
import java.awt.ComponentOrientation;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class Display {
final static boolean shouldFill = true;
final static boolean shouldWeightX = true;
final static boolean RIGHT_TO_LEFT = false;
public static void addComponentsToPane(Container pane) {
if (RIGHT_TO_LEFT) {
pane.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
}
JButton button;
JLabel label;
pane.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
if (shouldFill) {
//natural height, maximum width
c.fill = GridBagConstraints.HORIZONTAL;
}
if (shouldWeightX) {
c.weightx = 0.5;
}
...
button = new JButton("Value Bet");
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 0;
c.gridx = 0;
c.gridy = 1;
pane.add(button, c);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
//Execute when button is pressed
JFrame frame = new JFrame("Value Bet");
frame.setVisible(true);
frame.setSize(500,300);
GridBagLayout layout = new GridBagLayout();
frame.setLayout(layout);
GridBagConstraints c = new GridBagConstraints();
JLabel label;
JTextField tf;
if (shouldFill) {
//natural height, maximum width
c.fill = GridBagConstraints.HORIZONTAL;
}
if (shouldWeightX) {
c.weightx = 0.5;
}
...
final JTextField tf1 = new JTextField();
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 1;
c.gridy = 2;
frame.add(tf1, c);
tf1.getDocument().addDocumentListener(new DocHandler(){
public class DocHandler implements DocumentListener{
@Override
public void changedUpdate(DocumentEvent arg0) {
tfHasChanged();
}
@Override
public void insertUpdate(DocumentEvent arg0) {
tfHasChanged();
}
@Override
public void removeUpdate(DocumentEvent arg0) {
tfHasChanged();
}
}
public void tfHasChanged(){
double chance1 = Double.parseDouble(tf1.getText());
}
});
... div components
}
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("Betting Application");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Set up the content pane.
addComponentsToPane(frame.getContentPane());
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
推荐答案
对于数字，您必须实现DocumentFilter或直接将JFormattedTextField与数字格式化程序一起使用
For Numbers you have to implementing DocumentFilter or directly to use JFormattedTextField with Number formatter
那么可能的方式(块执行)代码行
then possible way (block executions) codelines
formatter.setMinimum(0.0);
formatter.setMaximum(1000.00);
并为textField1添加一些公式，例如textField1等于textField2中的值，例如
and add some formulas for textField1, for example textField1 equals value from textField2 e.g.
import java.awt.*;
import java.awt.font.TextAttribute;
import java.math.*;
import java.text.*;
import java.util.Map;
import javax.swing.*;
import javax.swing.JFormattedTextField.*;
import javax.swing.event.*;
import javax.swing.text.InternationalFormatter;
public class DocumentListenerAdapter {
public static void main(String args[]) {
JFrame frame = new JFrame("AbstractTextField Test");
final JFormattedTextField textField1 = new JFormattedTextField(new Float(10.01));
textField1.setFormatterFactory(new AbstractFormatterFactory() {
@Override
public AbstractFormatter getFormatter(JFormattedTextField tf) {
NumberFormat format = DecimalFormat.getInstance();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
format.setRoundingMode(RoundingMode.HALF_UP);
InternationalFormatter formatter = new InternationalFormatter(format);
formatter.setAllowsInvalid(false);
formatter.setMinimum(0.0);
formatter.setMaximum(1000.00);
return formatter;
}
});
final Map attributes = (new Font("Serif", Font.BOLD, 16)).getAttributes();
attributes.put(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON);
final JFormattedTextField textField2 = new JFormattedTextField(new Float(10.01));
textField2.setFormatterFactory(new AbstractFormatterFactory() {
@Override
public AbstractFormatter getFormatter(JFormattedTextField tf) {
NumberFormat format = DecimalFormat.getInstance();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
format.setRoundingMode(RoundingMode.HALF_UP);
InternationalFormatter formatter = new InternationalFormatter(format);
formatter.setAllowsInvalid(false);
//formatter.setMinimum(0.0);
//formatter.setMaximum(1000.00);
return formatter;
}
});
textField2.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void changedUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
@Override
public void insertUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
@Override
public void removeUpdate(DocumentEvent documentEvent) {
printIt(documentEvent);
}
private void printIt(DocumentEvent documentEvent) {
DocumentEvent.EventType type = documentEvent.getType();
double t1a1 = (((Number) textField2.getValue()).doubleValue());
if (t1a1 > 1000) {
Runnable doRun = new Runnable() {
@Override
public void run() {
textField2.setFont(new Font(attributes));
textField2.setForeground(Color.red);
}
};
SwingUtilities.invokeLater(doRun);
} else {
Runnable doRun = new Runnable() {
@Override
public void run() {
textField2.setFont(new Font("Serif", Font.BOLD, 16));
textField2.setForeground(Color.black);
}
};
SwingUtilities.invokeLater(doRun);
}
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(textField1, BorderLayout.NORTH);
frame.add(textField2, BorderLayout.SOUTH);
frame.setVisible(true);
frame.pack();
}
private DocumentListenerAdapter() {
}
}
这篇关于如何实现文档侦听器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！
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