c#服务器端构造json对象，字符串过滤函数string2Json

public String string2Json(String s)
        {
            StringBuilder sb = new StringBuilder(s.Length + 20);
            sb.Append('/"');
            for (int i = 0; i < s.Length; i++)
            {
                char c = s[i];
                switch (c)
                {
                    case '/"':
                        sb.Append("///"");
                        break;
                    case '//':
                        sb.Append("////");
                        break;
                    case '/':
                        sb.Append("///");
                        break;
                    case '/b':
                        sb.Append("//b");
                        break;
                    case '/f':
                        sb.Append("//f");
                        break;
                    case '/n':
                        sb.Append("//n");
                        break;
                    case '/r':
                        sb.Append("//r");
                        break;
                    case '/t':
                        sb.Append("//t");
                        break;
                    default:
                        sb.Append(c);
                        break;
                }
            }
            sb.Append('/"');
            return sb.ToString();
        }