C# 统计字符串出现的个数

   string str1 = "123AAA456AAAA789AAAAAAA1011";
            string str2 = "123456789AAA23456789AAAA3456789AAAAAAA4567890";
            string str3 = "123456788AAA23456789AAAA3456789AAAAAAA4567890";
            string str4 = "123456788AAA0AAAA0AAAAAAA";
            var strArry = (str1 + "&" + str2 + "&" + str3 + "&" + str4).Split('&'); //把字符串连接为数组
            char[] str1Arry = str1.ToArray();
            int js = ;
            List<int> TempArry = new List<int>();
            for (int i = ; i < str1Arry.Length; i++)
            {
                if (str1Arry[i] == 'A')
                {
                    js++;
                    continue;
                }
                if (js != ) //找到A, 不等于A时候执行
                {
                    TempArry.Add(js);
                    js = ; //js归0
                }
            }