在DataRow中将CreatedDate和ModifiedDate放入哪里的好地方？

Question

I have the following code

public class SpecialItemRow : DataRow
    {
        public SpecialItemRow(DataRowBuilder builder)
            : base(builder)
        {
            CreatedDate = DateTime.Now.ToLongTimeString();
        }

        public string ItemName { get { return Convert.ToString(base["_ItemName"]); } set { base["_ItemName"] = value; _UpdateModifiedDate(); } }
        public string Price { get { return Convert.ToString(base["_Price"]); } set { base["_Price"] = value; _UpdateModifiedDate(); } }
        public string CreatedDate { get { return Convert.ToString(base["_CreatedDate"]); } set { base["_CreatedDate"] = value; _UpdateModifiedDate(); } }
        public string ModifiedDate { get { return Convert.ToString(base["_ModifiedDate"]); } set { base["_ModifiedDate"] = value; } }

        private void _UpdateModifiedDate()
        {
            ModifiedDate = DateTime.Now.ToLongTimeString();
        }
    }

which tries to set the modified and created dates automatically. but it turns out that those are not the right places to put. is there any other overridable methods to set these values? Thanks.

Answer 1

Do this in DataTable using OnRowChanged (or OnRowChanging). For example,

public class SpecialItemTable : DataTable
{

   protected override void OnRowChanged(DataRowChangeEventArgs e)
   {
      if (e.Action == DataRowAction.Add)
      {
         r.Row["CreatedDate"] = DateTime.Now;
      }
      else if (e.Action == DataRowAction.Change)
      {
         var time = DateTime.Now;
         // Check to prevent the cascaded row change events
         if ((time - (DateTime)e.Row["LastUpdated"]).TotalMilliseconds > 2)
         {
            e.Row["LastUpdated"] = time;
         }
      }
   }
}

(Disclaimer: Untested code - provided to just give an idea)