C # determines how many characters comprising the string

private void button1_Click(object sender, EventArgs e)
{
    ArrayList itemList = new ArrayList();
    CharEnumerator CEnumerator = textBox1.Text.GetEnumerator();
    Regex regex = new Regex("^[\u4E00-\u9FA5]{0,}$");
    while (CEnumerator.MoveNext())
    {
　　　　　if (regex.IsMatch(CEnumerator.Current.ToString(), 0))
    　　　　 itemList.Add(CEnumerator.Current.ToString());
　　　　　textBox2.Text = itemList.Count.ToString();
    }
}

May be used string.GetEnumerator () Returns a string CharEnumerator objects, and the object traversing for a regular character determination.