System.FormatException: Index (zero based) must be greater than or equal to zero and less than the size of the argument list

        static void Main(string[] args)
        {
            StringBuilder sb = new StringBuilder(); 
            string test = "124454664{0}89jnhb";
            string formattedMessage = string.Format(test, args);
   
        }

主要原因是字符串中有{}, 被string.Format调用时报错。

Replace即可。

            StringBuilder sb = new StringBuilder(); 
            string test = "124454664{0}89jnhb";
            test = test.Replace("{", "[").Replace("}", "]"); 
            string formattedMessage = string.Format(test, args);
   

或者 将 { 替换为 {{