主从表设计中为何不能更新明细表中的列

charpin 2010-05-15 10:59:49

请看如下的代码段，在dtPurchaseDetail_ColumnChanged事件中完成了统计明细表中的金额，然后写入主表中，奇怪的是有了这段程序后，我却不能向明细表中添加记录了，好像主从表的关系不起作用了，然后我把drPurchaseMaster.BeginEdit()到
drPurchaseMaster.EndEdit()这段注释掉就没问题,请问各位知道是哪里有问题吗



    Public Class frmPurchase

    Dim bmPurchaseDetail As BindingManagerBase

    Dim bmPurchaseMaster As BindingManagerBase

    Dim WithEvents dtPurchaseDetail As New DataTable

    Dim PurchaseDetailHasChange As Boolean

    Private Sub frmPurchase_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        bmPurchaseMaster = Me.BindingContext(DsPurchase1, "PurchaseMaster")

        bmPurchaseDetail = Me.BindingContext(DsPurchase1, "PurchaseMaster.FK_PurchaseMaster_PurchaseDetail")

        dtPurchaseDetail = MyDataSet.Tables("PurchaseDetail")



        PurchaseDetailHasChange = True



        MyDataSet.Tables("PurchaseMaster").Columns("AccountPayable").DefaultValue = 0

        MyDataSet.Tables("PurchaseMaster").Columns("Paid").DefaultValue = 0

        MyDataSet.Tables("PurchaseMaster").Columns("Subtotal").DefaultValue = 0

        MyDataSet.Tables("PurchaseMaster").Columns("ValueAddTax").DefaultValue = 0

        MyDataSet.Tables("PurchaseMaster").Columns("Amount").DefaultValue = 0



        MyDataSet.Tables("PurchaseDetail").Columns("ProductID2").DefaultValue = "NULL"

        MyDataSet.Tables("PurchaseDetail").Columns("PurchaseQuantity").DefaultValue = 0

        MyDataSet.Tables("PurchaseDetail").Columns("PurchaseUnitPrice").DefaultValue = 0

        MyDataSet.Tables("PurchaseDetail").Columns("PurchaseAmount").DefaultValue = 0



    End Sub

    Public Overrides Sub SetMyDataSet()

        Dim dataCon As New KS.DataConnection

        cnKS.ConnectionString = dataCon.getConnection

        MyDataSet = DsPurchase1

        MyDataItem = "PurchaseMaster"

        MyConnection = cnKS

        'MyBase.SetMyDataSet()

    End Sub

    Public Overrides Sub FillData()

        daPurchaseMaster.Fill(MyDataSet, "PurchaseMaster")

        daPurchaseDetail.Fill(MyDataSet, "PurchaseDetail")

        daSupplier.Fill(MyDataSet, "Supplier")

    End Sub

    Public Overrides Sub UploadAddData()

        UpdateData()

    End Sub

    Public Overrides Sub UploadModifyData()

        UpdateData()

    End Sub

    Public Overrides Sub UploadDeletedData()

        UpdateData()

    End Sub

    Public Sub UpdateData()

        daPurchaseMaster.Update(MyDataSet, "PurchaseMaster")

        daPurchaseDetail.Update(MyDataSet, "PurchaseDetail")

    End Sub



    Private Sub dgDetail_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles dgDetail.CellContentClick



    End Sub



    Private Sub dgDetail_DoubleClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles dgDetail.DoubleClick

        'bmPurchaseMaster.EndCurrentEdit()

        bmPurchaseDetail.EndCurrentEdit()

        Dim frmSelectProductID As New frmSelectProductID()

        If frmSelectProductID.ShowDialog() = Windows.Forms.DialogResult.OK Then

            dgDetail.Item(0, dgDetail.CurrentRow.Index).Value = frmSelectProductID.ProductID

        End If

    End Sub



    Private Sub dtPurchaseDetail_ColumnChanged(ByVal sender As System.Object, ByVal e As System.Data.DataColumnChangeEventArgs) Handles dtPurchaseDetail.ColumnChanged

        Dim drPurchaseMaster As DataRow

        Dim drPurchaseDetail As DataRow

        Dim iSubtotal As Integer

        Try

            If PurchaseDetailHasChange Then

                'MessageBox.Show(bmPurchaseMaster.Position)

                PurchaseDetailHasChange = False

                e.Row("PurchaseAmount") = e.Row("PurchaseQuantity") * e.Row("PurchaseUnitPrice")

                iSubtotal = 0

                drPurchaseMaster = Me.DsPurchase1.Tables("PurchaseMaster").Rows(bmPurchaseMaster.Position)

                For Each drPurchaseDetail In drPurchaseMaster.GetChildRows("FK_PurchaseMaster_PurchaseDetail")

                    iSubtotal = iSubtotal + drPurchaseDetail("PurchaseAmount")

                Next

                'MessageBox.Show(bmPurchaseMaster.Position)

                'messagebox.Show(dspurchase1.Tables("PurchaseMaster")



                'MessageBox.Show(drPurchaseMaster.RowState)

                drPurchaseMaster.BeginEdit()

                'MessageBox.Show(drPurchaseMaster.RowState)



                'TextBox9.Text = iSubtotal

                'TextBox10.Text = iSubtotal * 0.05

                'TextBox11.Text = TextBox9.Text + TextBox10.Text



                drPurchaseMaster("SubTotal") = iSubtotal

                drPurchaseMaster("ValueAddTax") = drPurchaseMaster("SubTotal") * 0.05

                drPurchaseMaster("Amount") = drPurchaseMaster("SubTotal") + drPurchaseMaster("ValueAddTax")

                drPurchaseMaster.EndEdit()



                'MessageBox.Show(drPurchaseMaster.RowState)

            End If



        Catch ex As Exception

            MessageBox.Show(ex.ToString)

        Finally

            PurchaseDetailHasChange = True



        End Try

    End Sub

End Class