datalist如何取主键

datalist怎么取主键
dlLy.DataKeyField = "LyId";
  int LyId = Convert.ToInt32(dlLy.DataKeys[0]);
LyId是主键

[解决办法]
dily.DataKeys[e.Item.ItemIndex].ToString()
这个可以获得主键
[解决办法]
dlLy.DataKeyField = "LyId"; 

某行的ID 就是 id=dily.DataKeys[e.Item.ItemIndex].ToString()