static void Main(string[] args){    new Program();}public string String1 = "aaaa";public string String2 = "bbbb";public string String3 = "cccc";public string String4 = "dddd";public string String5 = "eeee";public string String6 = "ffff";public Program(){    string temp = "";    Type type = this.GetType();    for (int i = 1; i < 7; i++)    {        FieldInfo fi = type.GetField("String" + i.ToString());        temp += fi.GetValue(this).ToString();    }    Console.WriteLine("111");    Console.WriteLine(temp);    Console.Read();}

Result:

aaaabbbbccccddddeeeeffff