.net static 变量

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            Common.SetDT();
            var dt = Common.DT;
        }
    }

    public class CacheHelper
    {
        public static DataTable DT = new DataTable();
    }

    public class Common
    {
        public static DataTable SetDT()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("ID");
            DataRow dr = dt.NewRow();
            dr["ID"] = "1";
            dt.Rows.Add(dr);
            CacheHelper.DT = dt;
            return CacheHelper.DT;
        }

        public static DataTable DT = CacheHelper.DT;
    }
}