string pattern = @"(?i)(\d+[^:：]+?)[:：]\s*?(\d+)(盒|瓶)";//定义匹配规则


            string tempStr = File.ReadAllText(@"C:\Users\M\Desktop\Test.txt", Encoding.GetEncoding("GB2312"));//读取文档

            StringBuilder sb = new StringBuilder();


            foreach (Match m in Regex.Matches(tempStr, pattern))
            {
                sb.Append(m.Value);//找到匹配项，并整合

            }
            this.richTextBox1.Text = sb.ToString();