private void richTextBox1_KeyUp(object sender, KeyEventArgs e)
        {
            StringBuilder chineseChar;
            int chineseChars = GetChineseLength(this.richTextBox1.Text.Trim(), out chineseChar);
            if (chineseChars > 0)
            {
                this.textBox1.Text = string.Format("共有 '{0}' 个汉字 ", chineseChars, chineseChar.ToString());
            }
我代码弄来弄去还是整不对啊

没有人吗，  求解答啊

给TEXT文本框开启值变动事件
获取长度给下TEXT赋值

TbChineseCounter显示中文字符数量，TbTotalCounter显示全部字符数量：

using System;
using System.Globalization;
using System.Text.RegularExpressions;
using System.Windows.Forms;

namespace WordCounter
{
    public partial class FormMain : Form
    {
        private static readonly Regex _cRegex = new Regex("[\u4e00-\u9fa5]");

        public FormMain()
        {
            InitializeComponent();
            Tb.TextChanged += Tb_TextChanged;
        }

        void Tb_TextChanged(object sender, EventArgs e)
        {
            var cCounter = 0;
            foreach (var c in Tb.Text)
            {
                if (!isChineseChar(c)) continue;
                cCounter++;
            }
            TbChineseCounter.Text = cCounter.ToString("n0");
            TbTotalCounter.Text   = Tb.Text.Length.ToString("n0");
        }

        static bool isChineseChar(char ch)
        {
            return _cRegex.IsMatch(ch.ToString(CultureInfo.InvariantCulture));
        }
    }
}