QTextEdit 匹配文本 进行高亮显示

QString search_text = ui->lineEdit->text();
	if (search_text.trimmed().isEmpty()) 
	{
		return;
	}
	else 
	{
		QTextDocument *document = ui->textEdit->document();
		bool found = false;
		QTextCursor highlight_cursor(document);
		QTextCursor cursor(document);
		//开始
		cursor.beginEditBlock();
		QTextCharFormat color_format(highlight_cursor.charFormat());
		color_format.setForeground(Qt::red);   //字体颜色
		color_format.setBackground(Qt::blue);  //背景颜色
		while (!highlight_cursor.isNull() && !highlight_cursor.atEnd()) 
		{
			//查找指定的文本，匹配整个单词
			highlight_cursor = document->find(search_text, highlight_cursor, QTextDocument::FindWholeWords);
			if (!highlight_cursor.isNull()) 
			{
				if (!found)
					found = true;
				highlight_cursor.mergeCharFormat(color_format);
			}
		}
		cursor.endEditBlock();
	}