# :-: 给代码添加高亮
在文件上右键选择`add new...`
将`class name`命名为`highlighter`
将`.pro`文件修改
```css
QT += widgets
requires(qtConfig(filedialog))
HEADERS = highlighter.h \
mainwindow.h
SOURCES = highlighter.cpp \
mainwindow.cpp \
main.cpp
# install
target.path = $$[QT_INSTALL_EXAMPLES]/widgets/richtext/syntaxhighlighter
INSTALLS += target
```
将`highlighter.h`的代码修改为
```css
#ifndef HIGHLIGHTER_H
#define HIGHLIGHTER_H
#include <QSyntaxHighlighter>
#include <QTextCharFormat>
#include <QRegularExpression>
QT_BEGIN_NAMESPACE
class QTextDocument;
QT_END_NAMESPACE
class Highlighter : public QSyntaxHighlighter
{
Q_OBJECT
public:
Highlighter(QTextDocument *parent = 0);
protected:
void highlightBlock(const QString &text) override;
private:
struct HighlightingRule
{
QRegularExpression pattern;
QTextCharFormat format;
};
QVector<HighlightingRule> highlightingRules;
QRegularExpression commentStartExpression;
QRegularExpression commentEndExpression;
QTextCharFormat keywordFormat;
QTextCharFormat classFormat;
QTextCharFormat singleLineCommentFormat;
QTextCharFormat multiLineCommentFormat;
QTextCharFormat quotationFormat;
QTextCharFormat functionFormat;
};
#endif // HIGHLIGHTER_H
```
将`highlighter.cpp`里的代码修改为
```css
#include "highlighter.h"
Highlighter::Highlighter(QTextDocument *parent)
: QSyntaxHighlighter(parent)
{
HighlightingRule rule;
keywordFormat.setForeground(Qt::darkBlue);
keywordFormat.setFontWeight(QFont::Bold);
QStringList keywordPatterns;
keywordPatterns << "\\bchar\\b" << "\\bclass\\b" << "\\bconst\\b"
<< "\\bdouble\\b" << "\\benum\\b" << "\\bexplicit\\b"
<< "\\bfriend\\b" << "\\binline\\b" << "\\bint\\b"
<< "\\blong\\b" << "\\bnamespace\\b" << "\\boperator\\b"
<< "\\bprivate\\b" << "\\bprotected\\b" << "\\bpublic\\b"
<< "\\bshort\\b" << "\\bsignals\\b" << "\\bsigned\\b"
<< "\\bslots\\b" << "\\bstatic\\b" << "\\bstruct\\b"
<< "\\btemplate\\b" << "\\btypedef\\b" << "\\btypename\\b"
<< "\\bunion\\b" << "\\bunsigned\\b" << "\\bvirtual\\b"
<< "\\bvoid\\b" << "\\bvolatile\\b" << "\\bbool\\b";
foreach (const QString &pattern, keywordPatterns) {
rule.pattern = QRegularExpression(pattern);
rule.format = keywordFormat;
highlightingRules.append(rule);
}
classFormat.setFontWeight(QFont::Bold);
classFormat.setForeground(Qt::darkMagenta);
rule.pattern = QRegularExpression("\\bQ[A-Za-z]+\\b");
rule.format = classFormat;
highlightingRules.append(rule);
singleLineCommentFormat.setForeground(Qt::red);
rule.pattern = QRegularExpression("//[^\n]*");
rule.format = singleLineCommentFormat;
highlightingRules.append(rule);
multiLineCommentFormat.setForeground(Qt::red);
quotationFormat.setForeground(Qt::darkGreen);
rule.pattern = QRegularExpression("\".*\"");
rule.format = quotationFormat;
highlightingRules.append(rule);
functionFormat.setFontItalic(true);
functionFormat.setForeground(Qt::blue);
rule.pattern = QRegularExpression("\\b[A-Za-z0-9_]+(?=\\()");
rule.format = functionFormat;
highlightingRules.append(rule);
commentStartExpression = QRegularExpression("/\\*");
commentEndExpression = QRegularExpression("\\*/");
}
void Highlighter::highlightBlock(const QString &text)
{
foreach (const HighlightingRule &rule, highlightingRules) {
QRegularExpressionMatchIterator matchIterator = rule.pattern.globalMatch(text);
while (matchIterator.hasNext()) {
QRegularExpressionMatch match = matchIterator.next();
setFormat(match.capturedStart(), match.capturedLength(), rule.format);
}
}
setCurrentBlockState(0);
int startIndex = 0;
if (previousBlockState() != 1)
startIndex = text.indexOf(commentStartExpression);
while (startIndex >= 0) {
QRegularExpressionMatch match = commentEndExpression.match(text, startIndex);
int endIndex = match.capturedStart();
int commentLength = 0;
if (endIndex == -1) {
setCurrentBlockState(1);
commentLength = text.length() - startIndex;
} else {
commentLength = endIndex - startIndex
+ match.capturedLength();
}
setFormat(startIndex, commentLength, multiLineCommentFormat);
startIndex = text.indexOf(commentStartExpression, startIndex + commentLength);
}
}
```
在`mainwindow.h`里添加
```css
//添加include文件
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include "highlighter.h"
#include <QMainWindow>
#include <QTextEdit> //文本
#include <QMenu> //加入菜单
#include <QMenuBar> //加入菜单栏
#include <QAction> //加入菜单栏
#include <QFileDialog>
```
找到`private:`添加
```css
Highlighter *highlighter;
```
如图
修改`mainwindow.cpp`
```css
highlighter = new Highlighter(editor->document());
```
位置如图
