Qt中QTextEdit限制只能输入数字英文逗号

m_pLineEdit = new QLineEdit(this);
    
//设置只能输入数字
m_pLineEdit->setValidator(new QIntValidator(1, 65535));
 
//设置只能输入英文大小写字母和英文逗号
QRegExp regexp;
regexp.setPattern("^[a-zA-Z0-9,]+$");
m_pLineEdit->setValidator(new QRegExpValidator(regexp));

//连接信号槽
connect(ui.textEdit, &QTextEdit::textChanged, this, &Widget::textEditChanged);
 
//槽函数实现
void Widget::textEditChanged()
{
	//只能输入数字 字母 英文逗号
	QRegExp reg;
	reg.setPattern("^[a-zA-Z0-9,]+$");
 
	QString strText = ui.textEdit->toPlainText();
 
	if (reg.exactMatch(strText))
	{
		m_symtext = strText;
	}
	else
	{
		ui.textEdit->setText(m_symtext);
	}
}

private:
    QString m_symtext;

void Widget::textEditChanged()
{
	//只能输入数字 字母 英文逗号
	QRegExp reg;
	reg.setPattern("^[a-zA-Z0-9,]+$");
	QString strText = ui.textEdit->toPlainText();
	if (reg.exactMatch(strText))
	{
		m_symtext = strText;
	}
	else
	{
		int offset = strText.length() - m_symtext.length();
		//改变光标的位置
		QTextCursor cursor = ui.textEdit->textCursor();
		auto pos = cursor.position();
		pos = pos >= offset ? pos - offset : pos;
		ui.textEdit->setText(m_symtext);
		cursor.setPosition(pos);
		ui.textEdit->setTextCursor(cursor);
	}
}

  QString textContent = this->toPlainText();
    int length = textContent.count();
    int maxLength = maxLen; // 最大字符数
    if(length > maxLength)
    {
        int position = this->textCursor().position();
        QTextCursor textCursor = this->textCursor();
        textContent.remove(position - (length - maxLength), length - maxLength);
        this->setText(textContent);
        textCursor.setPosition(position - (length - maxLength));
        this->setTextCursor(textCursor);
    }