产生错误的代码：

DataTable dtContract_src = Oper.GetDataTable("select * from T_Contract where ProjectID=" + ProjectID_src + " and Flag=0", con_src);                            foreach (DataRow dr in dtContract_src.Rows)                            {                                String ContractID_src = dr["ContractID"].ToString();                                DataTable dtContract_dst = Oper.GetDataTable("select * from T_Contract where ProjectID=" + ProjectID_src + " and ContractID=" + ContractID_src + " and Flag=0", con_dst);                                if (dtContract_dst.Rows.Count != 0)                                {                                    impContract_exist++;                                    continue;                                }                                dtContract_dst.Rows.Add(dr);                                String columns = "";                                String paramss = "";                                OleDbCommand updateCmd = con_dst.CreateCommand();                                foreach (DataColumn dc in dtContract_dst.Columns)                                {                                    if (columns == "")                                    {                                        columns = dc.ColumnName;                                        paramss = "@" + dc.ColumnName;                                    }                                    else                                    {                                        columns += ", " + dc.ColumnName;                                        paramss += ", @" + dc.ColumnName;                                    }                                    updateCmd.Parameters.Add(new OleDbParameter(dc.ColumnName, dc.DataType);                                }                                updateCmd.CommandText = "insert into T_Contract(" + columns + ") Values(" + paramss + ")";                                updateCmd.ExecuteNonQuery();                                //OleDbDataAdapter dataAdap = new OleDbDataAdapter();                                //dataAdap.InsertCommand = updateCmd;                                //dataAdap.Update(dtContract_dst);                            }

错误行：

dtContract_dst.Rows.Add(dr);

解决的方法：

dtContract_dst.Rows.Add(dr.ItemArray);