DataBinding困境

Question

因此，我有这个datagridview，它链接到绑定源，绑定到基础数据表。问题是，我需要手动将行添加到datagridview。

这是不能做到的，因为它是绑定的，所以我必须使用数据库。

如果我将行添加到基础datatable中，则在保存datatable时，行将被复制，这可能是因为绑定源以某种方式获得了一个副本并将其插入。

将其添加到绑定源是我一直在尝试的工作，但它并不完全有效。

让我详细解释一下我的设置是什么：

我有一个有两个表的数据库: CashReceiptTable和CashReceiptItemsTable

CashReceiptItemsTable包含一个FK到CashReceiptTable。

该表单允许用户添加和修改这两个表。

当用户输入新的现金收据时，现金收据的id是-1，而cashReceiptitemstable中的FK是-1。当数据库被保存时，现金收集器的id会被更新，我必须手动更新现金收集器的FK。

以下是问题所在：

当我试图在多行中更新CashReceiptID ( FK)时，第一行将被更新，并消失(因为它已被过滤)，其他行被移除，并且我无法再访问它们。

我不知道为什么，我还没有更新过滤器，所以它们应该仍然存在，但是尝试访问它们会抛出RowNotInTableException。

我管理了一项工作，将绑定源中的行复制到内存数组中，删除绑定源中的第一行(所有其他行都消失了)，更新该行的FK并将它们重新插入绑定源并保存表。

这很好，但是为什么行会消失呢？

我还有一个轻微的问题。当CashReceiptsTable为空并且向其添加一个新行时，如果我向CashReceiptsItemTable中添加了多个行，则会导致问题。当手动将项添加到绑定源时，添加一个新行将弹出到上一行，并将其推入datatable。这隐藏了它对我的FK更新例程，它是丢失的，它也从DataGridView中删除它。

只有当我将第一行添加到CashReceiptsTable时，它才会这样做。它为什么要这样做，我怎样才能解决它？

我在这里张贴我的自动脉冲代码：

        private void autopopulate(decimal totalPayment) {
            //remove old rows
            for (int i = 0; i < tblCashReceiptsApplyToBindingSource.List.Count; i++) {
                DataRowView viewRow = tblCashReceiptsApplyToBindingSource.List[i] as DataRowView;
                RentalEaseDataSet.tblCashReceiptsApplyToRow row = viewRow.Row as RentalEaseDataSet.tblCashReceiptsApplyToRow;

                if (row.CashReceiptsID == this.ReceiptID) {
                    tblCashReceiptsApplyToBindingSource.List.Remove(viewRow);
                    i--;
                }
            }

            decimal payment = totalPayment;

            //look for an exact amount
            foreach (DataGridViewRow dueRow in dataViewDueRO.Rows) {
                decimal due = -1 * (Decimal)dueRow.Cells[Due.Index].Value;
                if (due == payment) {
                    String charge = (String)dueRow.Cells[Description.Index].Value;
                    int chargeID = ManageCheckbooks.findTransactionID(charge);

                    tblCashReceiptsApplyToBindingSource.AddNew();

                    RentalEaseDataSet.tblCashReceiptsApplyToRow row = ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row as RentalEaseDataSet.tblCashReceiptsApplyToRow;
                    row.CashReceiptsID = this.ReceiptID;
                    row.ApplyTo = chargeID;

                    row.Paid = payment; //convert to positive

                    payment = 0;
                    break;
                }
            }

            //if the exact amount was found, payment will = 0, and this will do nothing, otherwise,
            //divy out everything left over (which will be everything)
            foreach (DataGridViewRow dueRow in dataViewDueRO.Rows) {
                String charge = (String)dueRow.Cells[Description.Index].Value;
                decimal due = (Decimal)dueRow.Cells[Due.Index].Value;

                if (due > 0 || payment <= 0) {
                    continue;
                }

                int chargeID = ManageCheckbooks.findTransactionID(charge);

                payment += due; //due is negative, so this will subtract how much the user owes

                tblCashReceiptsApplyToBindingSource.AddNew();

                RentalEaseDataSet.tblCashReceiptsApplyToRow row = ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row as RentalEaseDataSet.tblCashReceiptsApplyToRow;
                row.CashReceiptsID = this.ReceiptID;
                row.ApplyTo = chargeID;

                if (payment >= 0) {
                    //payment is enough to cover this
                    row.Paid = due * -1; //convert to positive
                } else {
                    //doesn't have enough money to conver this, can only cover partial, or none
                    row.Paid = (due - payment) * -1; //math:
                    //money remaining $50, current charge = $60
                    //payment = 50 + -60 = -10
                    //row["Paid"] = (-60 - -10) * -1
                    //row["Paid"] = (-60 + 10) * -1
                    //row["Paid"] = -50 * -1
                    //row["Paid"] = 50
                }

                if (payment <= 0) {
                    break; //don't conintue, no more money to distribute
                }
            }

            isVirginRow = true;
        }

这是将它保存到数据库中的函数：

    protected override void saveToDatabase() {
        tblCashReceiptsBindingSource.EndEdit();
        isVirginRow = false;

        RentalEaseDataSet.tblCashReceiptsRow[] rows = rentalEaseDataSet.tblCashReceipts.Select("ID < 0") as RentalEaseDataSet.tblCashReceiptsRow[];
        int newID = -1;
        if (rows.Count() > 0) {
            tblCashReceiptsTableAdapter.Update(rows[0]);
            newID = rows[0].ID;
        }

        tblCashReceiptsTableAdapter.Update(rentalEaseDataSet.tblCashReceipts);


        //update table
        /*foreach (RentalEaseDataSet.tblCashReceiptsApplyToRow row in rentalEaseDataSet.tblCashReceiptsApplyTo.Select("CashReceiptsID = -1")) {
            row.CashReceiptsID = newID;
        }*/

        //update binding source
        DataRowView[] applicationsOld = new DataRowView[tblCashReceiptsApplyToBindingSource.List.Count];
        RentalEaseDataSet.tblCashReceiptsApplyToRow[] applicationsNew = new RentalEaseDataSet.tblCashReceiptsApplyToRow[tblCashReceiptsApplyToBindingSource.List.Count];
        tblCashReceiptsApplyToBindingSource.List.CopyTo(applicationsOld, 0);
        for (int i = 0; i < applicationsOld.Count(); i++) {
            RentalEaseDataSet.tblCashReceiptsApplyToRow row = applicationsOld[i].Row as RentalEaseDataSet.tblCashReceiptsApplyToRow;

            if (row.CashReceiptsID < 0) {
                applicationsNew[i] = rentalEaseDataSet.tblCashReceiptsApplyTo.NewRow() as RentalEaseDataSet.tblCashReceiptsApplyToRow;
                applicationsNew[i]["ID"] = row.ID;
                applicationsNew[i]["CashReceiptsID"] = this.ReceiptID;
                applicationsNew[i][2] = row[2];
                applicationsNew[i][3] = row[3];
                applicationsNew[i][4] = row[4];
                //row.Delete();
            }
        }
        for (int i = 0; i < applicationsOld.Count(); i++) {
            try {
                if ((int)applicationsOld[i].Row["ID"] < 0) {
                    applicationsOld[i].Row.Delete();
                }
            } catch (RowNotInTableException) {
                break;
            }
        }
        this.tblCashReceiptsApplyToBindingSource.Filter = "CashReceiptsID = " + this.ReceiptID;

        foreach (DataRow newRow in applicationsNew) {
            if (newRow == null) {
                break;
            }
            tblCashReceiptsApplyToBindingSource.AddNew();
            ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row[0] = newRow[0];
            ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row[1] = newRow[1];
            ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row[2] = newRow[2];
            ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row[3] = newRow[3];
            ((DataRowView)tblCashReceiptsApplyToBindingSource.Current).Row[4] = newRow[4];
        }

        tblCashReceiptsApplyToBindingSource.EndEdit();

        checkForBadRows();

        tblCashReceiptsApplyToTableAdapter.Update(rentalEaseDataSet.tblCashReceiptsApplyTo);
        tblCashReceiptsApplyToTableAdapter.Fill(rentalEaseDataSet.tblCashReceiptsApplyTo);
    }

Answer 1

您可能需要尝试将行添加到DataGridView。由于您是绑定到它，DataGridView成为您的‘接入点’。

我有几个绑定到DataGridView的应用程序，在大多数情况下，当我添加一行时，我都是通过DataGridView来实现的。它已经有了允许您相对容易地添加的属性/方法/事件。

如果你需要更多的信息我可以更新。