C#判断汉字的个数

  private void btnNum_Click(object sender, EventArgs e)        {            if (txtWords.Text.Length == 0)                      //判断是否为空            {                MessageBox.Show("请输入汉字:");                        return;                                                 }            Regex reg = new Regex("^[\u4E00-\u9FA5]{0,}$");            int iNumOfWords = 0;            for (int i = 0; i < txtWords.Text.Length; i++)            {                iNumOfWords = reg.IsMatch(txtWords.Text[i].ToString()) ?                    ++iNumOfWords : iNumOfWords;            }            txtNum.Text = Convert.ToString(iNumOfWords);        }