我目前正在开发一个非常简单的 IDE，用于 Java 中的 C 编程。简单地说，我的意思是它有一些小的代码猜测（类似于 Eclipse）、一些小的自动完成（再一次，想想 Eclipse）和一些语法突出显示。我几乎把所有的事情都弄清楚并粗略了（即工作，但不漂亮或效率不高），除了我在正确的语法突出显示方面遇到了一些麻烦。
我的意思是；在我的代码 JFrame 中，我放入了一个 JTextPane，这样我就可以使用不同的字体、粗体、非粗体、斜体，并相对轻松地添加不同的文本颜色。我有一个键监听器连接到这个 JTextPane，并且在每次按下空格键时，它都会抓取你刚刚写的内容，通过“if”语句树运行它以查看你写的单词是否是关键字。如果你这样做了，它会尝试突出（或不突出）你刚刚写的内容。但是，在某些情况下，我需要它在点击空格键之前更改颜色（例如注释或#define 语句）。没问题，对吧？只需添加另一个“if”语句来检测是否已按下该键，如果已按下，则更改字体颜色。好吧，这就是我试图做的，但是它不起作用。
抱歉，如果这没有多大意义，如果需要，我很乐意解释一下。我还尽可能多地删除了不必要的代码，以尝试缩短它。
非常感谢您的宝贵时间！
〜美分
SSCCE：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JTextPane;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyledDocument;
public class Main implements Runnable
{
private static final long serialVersionUID = 1L;
private static final int WIDTH = 800;
private static final int HEIGHT = 600;
private static final String NAME = "";
private JFrame frame;
private JTextPane textPane = new JTextPane();
private int keysPressed = -1; /* Keys pressed */
private ArrayList<Integer> keyCode = new ArrayList<Integer>(); /* List of our keyCodes */
public void run()
{
frame = new JFrame(NAME);
frame.setPreferredSize(new Dimension(WIDTH, HEIGHT));
frame.setMinimumSize(new Dimension(WIDTH, HEIGHT));
frame.setMaximumSize(new Dimension(WIDTH, HEIGHT));
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(textPane, BorderLayout.CENTER);
textPane.setPreferredSize(new Dimension(WIDTH, HEIGHT));
textPane.setEditable(true);
textPane.addKeyListener(new KeyListener(){
@Override
public void keyPressed(KeyEvent e)
{
int previousPos; /* Previous position of the caret */
int length; /* Length of our grabbed string */
int currentPos; /* Current position of the caret */
String text; /* The entire text of the JTextPane */
String subText; /* Our sub-string-text we're using */
String subTextP; /* Our sub-string-text plus one character*/
boolean first = true; /* Be default, it's the first letter */
StyledDocument doc = textPane.getStyledDocument();
SimpleAttributeSet sas = new SimpleAttributeSet(); /* So we can set bold, and such */
keyCode.add(new Integer(e.getKeyCode())); /* The key pressed */
keysPressed++;
currentPos = textPane.getCaretPosition(); /* The current position of the caret */
text = textPane.getText(); /* Grabbing the text on the text pane */
previousPos = text.lastIndexOf(" ", currentPos); /* Getting the last position of a space */
if(previousPos <= 0) /* If the position if before or equal to 0 */
{
previousPos = 0; /* Then the position is 0 */
}
length = currentPos - previousPos; /* The length of the string we're messing with, is between the two positions */
subText = text.substring(previousPos, currentPos); /* Grabbing the string between our two positions */
if(first) /* If this is the first letter, or insert */
{
if(keyCode.contains(KeyEvent.VK_SHIFT))
{
first = true;
subTextP = text.substring(0, 0); /* Then we want to grab it, at 0, 0 */
}
else
{
subTextP = text.substring(0, 0); /* Then we want to grab it, at 0, 0 */
first = false; /* it's no longer the first */
}
}
else /* If it isn't */
{
subTextP = text.substring(previousPos + 1, currentPos); /* Then we want to grab the usual */
}
subText = subText.replaceAll("[\\n\\t\\r]", ""); /* Getting rid of all the tabs and newlines */
subTextP = subTextP.replaceAll("[\\n\\t\\r]", ""); /*Getting rid of all the tabs and new lines */
if(keyCode.contains(KeyEvent.VK_3))
{
if(keyCode.contains(KeyEvent.VK_SHIFT))
{
System.out.println("Number sign hit!");
StyleConstants.setForeground(sas, Color.GREEN); /* Anything following a number sign will be green */
doc.setCharacterAttributes(previousPos, length, sas, false); /* Turning it green */
}
}
if(keyCode.contains(KeyEvent.VK_SPACE)) /* If a space has been hit! */
{
/* This is were we'll do all text coloring and such */
if(subText.equals(" if") || subText.equals("if") || subTextP.equals("if")) /* All things to be bolded */
{
StyleConstants.setForeground(sas, Color.GRAY); /* All of these statements will be gray... */
StyleConstants.setBold(sas, true); /* ... and bold */
doc.setCharacterAttributes(previousPos, length, sas, false); /* Making them so! */
StyleConstants.setBold(sas, false); /* We don't want these attributes to remain... */
StyleConstants.setForeground(sas, Color.black); /* ... So we're removing them. */
}
}
}
public void keyReleased(KeyEvent e)
{
for(int i = keysPressed; i >= 0; i--) /* For loop to remove all keyPresses from our list */
{
keyCode.remove(i); /* Removing the specified keyPress */
}
keysPressed = -1; /* Because the first index is 0, and we want to add one to keysPressed, we need to start below 0 */
}
@Override
public void keyTyped(KeyEvent arg0) {
}
});
frame.pack();
frame.setVisible(true);
}
public void start()
{
new Thread(this).start();
}
public final static void main(String args[])
{
new Main().start();
}
}
编辑：
要重现此问题，请运行上面提供的代码。在 textPane 中，输入单词“if”（不带引号），然后按空格键。这个词现在应该加粗，并且是灰色的。现在，尝试在它之后输入“#”（不带引号），（中间有空格）并点击空格或任何其他键；什么都没发生。但是，系统应该打印出“数字符号命中！” 一旦你输入一个“#”，这意味着代码实际上仍然可以访问。另请注意，我对“#”使用与“if”相同的代码（除了更改颜色）。希望能帮助你们更多地理解这个问题。