DataTable dt = new DataTable();
            dt.Columns.Add("Column1", typeof(int));
            DataRow dr1 = dt.NewRow();
            dr1["Column1"] = 1;
            dt.Rows.Add(dr1);
            DataRow dr2 = dt.NewRow();
            dr2["Column1"] = 2;
            dt.Rows.Add(dr2);
            DataRow dr3 = dt.NewRow();
            dr3["Column1"] = 3;
            dt.Rows.Add(dr3);
            DataRow dr4 = dt.NewRow();
            dr4["Column1"] = 10;
            dt.Rows.Add(dr4);
            DataRow dr5 = dt.NewRow();
            dr1["Column1"] = 20;
            dt.Rows.Add(dr5);
            DataRow dr6 = dt.NewRow();
            dr6["Column1"] = 30;
            dt.Rows.Add(dr6);
            DataTable p1 = new DataTable();
            p1 = dt.Copy();

------解决方案--------------------
DataTable dt=new DataTable();
adapter.fill(dt)
DataTable dtt=dt.Copy();  //没有问题啊。能复制到dt表的内容。