3

我从以下代码中收到错误“此行已属于此表”：

public static DataTable AddNewAllocations(string pCaseNo, ref DataTable pTable)
    {
        try
        {
            string sqlText = "SELECT UserID FROM tblUsers;";
            aSqlQuery aQ = new aSqlQuery(sqlText, "table");
            DataTable userTable = aQ.TableResult;

            foreach (DataRow userRow in userTable.Rows)
            {
                int allocAlready = 0;
                foreach (DataRow allocRow in pTable.Rows)
                {
                    if (allocRow["FeeEarner"].ToString() == userRow["UserID"].ToString())
                    {
                        allocAlready = 1;                            
                    }
                }
                if (allocAlready == 0)
                {
                    string strUser = userRow["UserID"].ToString();          
                    decimal fees = cTimesheet.UserFees(strUser, pCaseNo);
                    int intCaseNo = Int32.Parse(pCaseNo);
                    if (fees > 0)
                    {
                        Object[] array = new object[8];
                        array[0] = 0;
                        array[1] = intCaseNo;
                        array[2] = DateTime.Today;
                        array[3] = strUser;
                        array[4] = fees;
                        array[5] = 0;
                        array[6] = fees;
                        array[7] = true;
                        pTable.Rows.Add(array);
                    }
                }
            }
            return pTable;
        }

        catch (Exception eX)
        {
            throw new Exception("cAllocation: Error in NewAllocations()" + Environment.NewLine + eX.Message);
        }

当我单步执行代码时，我可以看到第二次抛出错误，访问以下行：

pTable.Rows.Add(array);

鉴于每次代码进入循环时我都会创建一个新的对象数组，我无法理解为什么我会收到此错误消息，这表明我正在多次添加同一行。当行每次由新的对象数组生成时，为什么代码将每个循环视为添加相同的数据行？

4

2 回答 2

5

另一种方法是在循环开始时创建一个 NewRow()，分配其数据，然后在循环底部创建 Rows.Add()。

{       
        // initialization code 
        // ...

        foreach (DataRow row in dt.Rows)
        {
            row.Delete();
        }
        Oda.Update(ds, "USERTABLE");

        DataRow  dr;

        foreach (var userRecord in urList)
        {
            dr = dt.NewRow();
            dr["username"] = userRecord.userName;
            dr["firstname"] = userRecord.firstName;
            dr["lastname"] = userRecord.lastName;
            dr["createdon"] = userRecord.createdOn;

            dt.Rows.Add(dr);
        }
        Oda.Update(ds, "USERTABLE");
}
于 2016-01-06T15:52:59.897 回答
1

最终起作用的代码是这样的：

public static DataTable AddNewAllocations(string pCaseNo, DataTable pTable)
    {
        try
        {
            DataTable newTable = NewAllocationTable(); 

            string sqlText = "SELECT UserID FROM tblUsers;";
            aSqlQuery aQ = new aSqlQuery(sqlText, "table");
            DataTable userTable = aQ.TableResult;

            foreach (DataRow userRow in userTable.Rows)
            {
                int allocAlready = 0;
                foreach (DataRow allocRow in pTable.Rows)
                {
                    if (allocRow["FeeEarner"].ToString() == userRow["UserID"].ToString())
                    {
                        allocAlready = 1;                            
                    }
                }

                if (allocAlready == 0)
                {
                    string strUser = userRow["UserID"].ToString();          
                    decimal fees = cTimesheet.UserFees(strUser, pCaseNo);
                    int intCaseNo = Int32.Parse(pCaseNo);
                    if (fees > 0)
                    {
                        Object[] array = new object[8];
                        array[0] = 0;
                        array[1] = intCaseNo;
                        array[2] = DateTime.Today;
                        array[3] = strUser;
                        array[4] = fees;
                        array[5] = 0;
                        array[6] = fees;
                        array[7] = true;
                        newTable.Rows.Add(array);
                    }
                }
            }

            foreach (DataRow row in pTable.Rows)
            {
                newTable.ImportRow(row);
            }

            newTable.DefaultView.Sort = "AllocID";
            return newTable;
        }

        catch (Exception eX)
        {
            throw new Exception("cAllocation: Error in NewAllocations()" + Environment.NewLine + eX.Message);
        }
    }

我认为关键是使用 ImportRow 而不是 Rows.Add。我仍然在我的方法中使用 Rows.Add，但仅在将行添加到新创建的表时。然后，我遍历作为参数传入的现有表，并使用 ImportRow 将参数表的每一行添加到新创建的表中。然后，我在我的 return 语句中传递新的组合表，而不是修改后的参数表。

于 2012-09-13T13:25:22.733 回答