Java 如何实现documentlistener
我已经创建了一些文本字段,我想从中使用用户输入。我已经读到我应该使用documentlistener,但是在我认为正确的地方实现它有一些困难 在代码中,我试图将其实现到文本字段tf1。im应该得到的输入被解析为一个double,这样我就可以对它进行一些数学计算 这是我试图实现它的代码Java 如何实现documentlistener,java,swing,user-interface,gridbaglayout,documentlistener,Java,Swing,User Interface,Gridbaglayout,Documentlistener,我已经创建了一些文本字段,我想从中使用用户输入。我已经读到我应该使用documentlistener,但是在我认为正确的地方实现它有一些困难 在代码中,我试图将其实现到文本字段tf1。im应该得到的输入被解析为一个double,这样我就可以对它进行一些数学计算 这是我试图实现它的代码 import java.awt.ComponentOrientation; import java.awt.Container; import java.awt.Dimension; import java.awt
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();
}
});
}
}
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 然后是可能的方式(块执行)代码行
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
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() {
}
}
如果tf1是一个文本字段,则文档侦听器将实现3种方法,如changedUpdate、insertUpdate、removeUpdate
tf1.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void changedUpdate(DocumentEvent e){
//do some math
tf1.getText();
}
@Override
public void insertUpdate(DocumentEvent e) {
/do some math
tf1.getText();
}
@Override
public void removeUpdate(DocumentEvent e) {
// TODO Auto-generated method stub
}
});
我建议您放弃整个方法,使用模态对话框,正如我在上一个问题中建议的那样。或者,为了获得最好的帮助,至少解释一下为什么你不想采用这种方法。为了更快地获得更好的帮助,请发布一个。给定
“价值赌注”
,我一直认为最好的组件应该是一个JSpinner
,带有NumberModel
——但是OP似乎忽略了我@安德鲁·汤普森(Andrew Thompson)当然,我的坏习惯是,默认情况下,我从不检查askers用户档案,这是为了保护我的精神健康:-)我通常不检查档案,只是在我有强烈的似曾相识感的时候(哦,别激动,那些有趣的小技巧可能是正确的,因为我复制/粘贴了;)。