我知道这个问题已被问过好几次了。我正在尝试从另一个类刷新我的JTextPane，当我从我的主类中执行它时，它可以工作，但它没有任何其他类。我听说你需要使用线程来做它，但我还没有真正看到有人实现它。我尽可能简单地提供了下面的代码。有3个班级。谢谢！
以下是它的外观输出： http://imgur.com/fQVDFPk
______________________________________________________
public class frame extends JPanel implements Runnable {
public TextBox textbox = new TextBox();
Thread t1 = new Thread(new TextBox());
public void run(){
}
public frame(){
t1.start();
textField();
}
public void textField(){
add(textbox.sp);
}
}
___________________________________________________
//bunch of imports
public class TextBox implements Runnable {
JTextPane field = new JTextPane();
JScrollPane sp = new JScrollPane(field);
String name ="This is your message!!\n\n Message \n\n Message";
public void run(){
try{
Thread.sleep(2000);
System.out.println("hello thread");
}catch(Exception e){}
}
public TextBox(){
field.setText("Welcome to Stack Overflow!!\n");
Message();
}
public void Message(){
Style style = field.addStyle("I'm a Style", null);
StyledDocument doc = field.getStyledDocument();
StyleConstants.setForeground(style, Color.BLACK);
field.setCaretPosition(field.getText().length());
try { doc.insertString(doc.getLength(), GetText(),style); }
catch (BadLocationException e){}
Color color=new Color(255,255,255);
field.setBackground(color);
sp.setBounds(100, 335, 350, 100);
field.setEditable(false);
sp.setAutoscrolls(true);
}
public String GetText ( )
{
return name;
}
public void SetText (String PassedText)
{
name = PassedText;
}
}
//我已经创建了一个新类来演示我在更改文档时要做的事情。
public class ChangePane {
public TextBox textbox = new TextBox();
ChangePane(){
Style style = textbox.field.addStyle("I'm a Style", null);
StyledDocument doc = textbox.field.getStyledDocument();
try {doc.insertString(doc.getLength(), "TESTING ADDITION",style);}catch(BadLocationException e){}
textbox.Message();
}
}
答案 0 :(得分：4)
我正在尝试从另一个类
刷新我的JTextPane
至于更新另一个类中的字段，您应该为包含该字段的类提供一个其他类可以调用的公共方法，以更改该字段的状态。例如，如果您想允许其他类更改JTextField中的文本，请为您的类提供如下方法：
public void setMyTextFieldText(String text) {
myTextField.setText(text);
// or if a JTextPane by inserting text into its Document here
}
这与Swing或GUI无关，而与基本的Java和面向对象的编码有关。对于一个JTextPane，你需要做更多的事情，然后就是setText，我相信，但我不会使用它们。
当我从我的主要课程中这样做时，它可以工作，但它没有任何其他课程。我听说你需要使用线程来做它，但我还没有真正看到有人实现它。我尽可能简单地提供了下面的代码。
如果您从作为主Swing线程的EDT（事件调度线程）中更改Swing GUI，则会出现线程问题。如果发生这种情况，那么您应该将Swing调用排入Swing事件线程，方法是将其放入Runnable并放入Swing事件队列：
SwingUtilities.invokeLater(new Runnable() {
public void run() {
// your swing calls go here
}
});
编辑1
请注意，您的这种方法没有任何用处：
// you should rename this setText(String passedText)
public void SetText (String PassedText)
{
name = PassedText;
// you need to change your JTextPane's Document in here *****
}
它只是更改名称String字段引用的文本，但不会更改任何显示的文本。您必须通过调用JTextPane方法来更改JTextPane文本，方法是将文本插入到JTextPane的Document中。
编辑2
请了解并使用Java命名约定，以免混淆那些可能想要了解您的代码并帮助您的人。类名应以大写字母开头，变量和字段名称以小写字母开头。您的命名似乎是倒退。
编辑3
您知道这里有两个完全独立的TextBox对象：
public TextBox textbox = new TextBox();
Thread t1 = new Thread(new TextBox());
改变一个状态对另一个没有影响。
另外，为什么让组件类实现Runnable，然后将它们放在Threads中。这没什么意义。要了解Swing线程，请阅读Concurrency in Swing。
编辑4
sscce的一个例子：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.*;
import javax.swing.text.*;
public class TextBoxTest {
private JPanel mainPanel = new JPanel();
private MyTextBox myTextBox = new MyTextBox();
private JTextArea textArea = new JTextArea(20, 30);
@SuppressWarnings("serial")
public TextBoxTest() {
JScrollPane scrollPane = new JScrollPane(textArea);
scrollPane.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("JTextArea"),
scrollPane.getBorder()));
JPanel centerPanel = new JPanel(new GridLayout(1, 0));
centerPanel.add(myTextBox.getMainComponent());
centerPanel.add(scrollPane);
JPanel bottomPanel = new JPanel();
bottomPanel.add(new JButton(new AbstractAction("Submit Text") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_S);
}
@Override
public void actionPerformed(ActionEvent e) {
try {
myTextBox.setText(textArea.getText());
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
}));
bottomPanel.add(new JButton(new AbstractAction("Append Text") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_A);
}
@Override
public void actionPerformed(ActionEvent e) {
try {
myTextBox.appendText(textArea.getText() + "\n");
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
}));
bottomPanel.add(new JButton(new AbstractAction("Append Red Text") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_R);
}
@Override
public void actionPerformed(ActionEvent e) {
try {
myTextBox.appendTextInRed(textArea.getText() + "\n");
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
}));
mainPanel.setLayout(new BorderLayout());
mainPanel.add(centerPanel, BorderLayout.CENTER);
mainPanel.add(bottomPanel, BorderLayout.PAGE_END);
}
public JComponent getMainComponent() {
return mainPanel;
}
private static void createAndShowGui() {
TextBoxTest textBoxTester = new TextBoxTest();
JFrame frame = new JFrame("TextBoxTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(textBoxTester.getMainComponent());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyTextBox {
private JTextPane textPane = new JTextPane();
private JScrollPane scrollPane = new JScrollPane(textPane);
private String name = "This is your message!! Message Message "
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!! Message Message "
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!!\n\n Message \n\n Message \n\n";
private StyledDocument doc = textPane.getStyledDocument();
public MyTextBox() {
addStylesToDocument(doc);
textPane.setEditable(false);
textPane.setFocusable(false);
try {
doc.insertString(0, name, doc.getStyle("regular"));
} catch (BadLocationException e) {
e.printStackTrace();
}
scrollPane.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("JTextPane"),
scrollPane.getBorder()));
}
private void addStylesToDocument(StyledDocument doc2) {
Style def = StyleContext.getDefaultStyleContext().getStyle(
StyleContext.DEFAULT_STYLE);
Style regular = doc.addStyle("regular", def);
StyleConstants.setFontFamily(def, "SansSerif");
StyleConstants.setFontSize(regular, 16);
Style s = doc.addStyle("red", regular);
StyleConstants.setForeground(s, Color.red);
}
public JScrollPane getMainComponent() {
return scrollPane;
}
public void setText(String text) throws BadLocationException {
doc.remove(0, doc.getLength());
doc.insertString(0, text, doc.getStyle("regular"));
}
public void appendText(String text) throws BadLocationException {
doc.insertString(doc.getLength(), text, doc.getStyle("regular"));
}
public void appendTextInRed(String text) throws BadLocationException {
doc.insertString(doc.getLength(), text, doc.getStyle("red"));
}
}
编辑5
要从另一个线程发送，正如我在其他地方所述，只需将代码包装到Runnable中，然后通过SwingUtilities.invokeLater(myRunnable)将其排入EDT。
例如，我可以为MyTextBox类提供一个完成所有这些操作的方法，任何外部类都可以调用它：
public void appendTextOffEdt(final String text) {
// first make sure that we're in fact off of the EDT
if (SwingUtilities.isEventDispatchThread()) {
try {
appendTextInRedBold(text);
} catch (BadLocationException e) {
e.printStackTrace();
}
} else {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
appendTextInRedBold(text);
} catch (BadLocationException e) {
e.printStackTrace();
}
}
});
}
}
例如：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.*;
import javax.swing.text.*;
public class TextBoxTest {
private JPanel mainPanel = new JPanel();
private MyTextBox myTextBox = new MyTextBox();
private JTextArea textArea = new JTextArea(20, 30);
private SendTextOffEdt sendTextOffEdt = new SendTextOffEdt(myTextBox);
@SuppressWarnings("serial")
public TextBoxTest() {
JScrollPane scrollPane = new JScrollPane(textArea);
scrollPane.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("JTextArea"),
scrollPane.getBorder()));
JPanel centerPanel = new JPanel(new GridLayout(1, 0));
centerPanel.add(myTextBox.getMainComponent());
centerPanel.add(scrollPane);
JPanel bottomPanel = new JPanel();
new Thread(sendTextOffEdt).start();
bottomPanel.add(new JButton(new AbstractAction("Append Text") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_A);
}
@Override
public void actionPerformed(ActionEvent e) {
try {
myTextBox.appendText(textArea.getText() + "\n");
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
}));
bottomPanel.add(new JButton(new AbstractAction("Append Blue Text") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_B);
}
@Override
public void actionPerformed(ActionEvent e) {
try {
myTextBox.appendTextInBlue(textArea.getText() + "\n");
} catch (BadLocationException e1) {
e1.printStackTrace();
}
}
}));
bottomPanel.add(new JButton(new AbstractAction("Exit") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_X);
}
@Override
public void actionPerformed(ActionEvent e) {
Window win = SwingUtilities.getWindowAncestor(mainPanel);
win.dispose();
}
}));
mainPanel.setLayout(new BorderLayout());
mainPanel.add(centerPanel, BorderLayout.CENTER);
mainPanel.add(bottomPanel, BorderLayout.PAGE_END);
}
public JComponent getMainComponent() {
return mainPanel;
}
private static void createAndShowGui() {
TextBoxTest textBoxTester = new TextBoxTest();
JFrame frame = new JFrame("TextBoxTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(textBoxTester.getMainComponent());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class SendTextOffEdt implements Runnable {
private static final long SLEEP_TIME = 3000;
private static final String TEXT = "Sent off of EDT\n";
private MyTextBox myTextBox;
public SendTextOffEdt(MyTextBox myTextBox) {
this.myTextBox = myTextBox;
}
@Override
public void run() {
while (true) {
myTextBox.appendTextOffEdt(TEXT);
try {
Thread.sleep(SLEEP_TIME);
} catch (InterruptedException e) {
}
}
}
}
class MyTextBox {
public static final String REGULAR = "regular";
public static final String BLUE = "blue";
public static final String RED_BOLD = "red bold";
private JTextPane textPane = new JTextPane();
private JScrollPane scrollPane = new JScrollPane(textPane);
private String name = "This is your message!! Message Message "
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!! Message Message "
+ "This is your message!!\n\n Message \n\n Message \n\n"
+ "This is your message!!\n\n Message \n\n Message \n\n";
private StyledDocument doc = textPane.getStyledDocument();
public MyTextBox() {
addStylesToDocument(doc);
textPane.setEditable(false);
textPane.setFocusable(false);
try {
doc.insertString(0, name, doc.getStyle("regular"));
} catch (BadLocationException e) {
e.printStackTrace();
}
scrollPane.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("JTextPane"),
scrollPane.getBorder()));
}
private void addStylesToDocument(StyledDocument doc2) {
Style def = StyleContext.getDefaultStyleContext().getStyle(
StyleContext.DEFAULT_STYLE);
Style regular = doc.addStyle(REGULAR, def);
StyleConstants.setFontFamily(def, "SansSerif");
StyleConstants.setFontSize(regular, 16);
Style s = doc.addStyle(BLUE, regular);
StyleConstants.setForeground(s, Color.blue);
s = doc.addStyle(RED_BOLD, regular);
StyleConstants.setBold(s, true);
StyleConstants.setForeground(s, Color.red);
}
public JScrollPane getMainComponent() {
return scrollPane;
}
public void setText(String text) throws BadLocationException {
doc.remove(0, doc.getLength());
doc.insertString(0, text, doc.getStyle(REGULAR));
}
public void appendText(String text) throws BadLocationException {
doc.insertString(doc.getLength(), text, doc.getStyle(REGULAR));
}
public void appendTextInBlue(String text) throws BadLocationException {
doc.insertString(doc.getLength(), text, doc.getStyle(BLUE));
}
public void appendTextInRedBold(String text) throws BadLocationException {
doc.insertString(doc.getLength(), text, doc.getStyle(RED_BOLD));
}
public void appendTextOffEdt(final String text) {
// first make sure that we're in fact off of the EDT
if (SwingUtilities.isEventDispatchThread()) {
try {
appendTextInRedBold(text);
} catch (BadLocationException e) {
e.printStackTrace();
}
} else {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
appendTextInRedBold(text);
} catch (BadLocationException e) {
e.printStackTrace();
}
}
});
}
}
}
至于教程：