dsmaster.vb

东软内部材料（六）ado .net相关

        
        Public Function IsCityNull() As Boolean
            Return Me.IsNull(Me.tableCustomerList.CityColumn)
        End Function
        
        Public Sub SetCityNull()
            Me(Me.tableCustomerList.CityColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsCountryNull() As Boolean
            Return Me.IsNull(Me.tableCustomerList.CountryColumn)
        End Function
        
        Public Sub SetCountryNull()
            Me(Me.tableCustomerList.CountryColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsPostalCodeNull() As Boolean
            Return Me.IsNull(Me.tableCustomerList.PostalCodeColumn)
        End Function
        
        Public Sub SetPostalCodeNull()
            Me(Me.tableCustomerList.PostalCodeColumn) = System.Convert.DBNull
        End Sub
        
        Public Function Is_RegionNull() As Boolean
            Return Me.IsNull(Me.tableCustomerList._RegionColumn)
        End Function
        
        Public Sub Set_RegionNull()
            Me(Me.tableCustomerList._RegionColumn) = System.Convert.DBNull
        End Sub
    End Class
    
    Public Class CustomerListRowChangeEvent
        Inherits EventArgs
        
        Private eventRow As CustomerListRow
        
        Private eventAction As System.Data.DataRowAction
        
        Public Sub New(ByVal row As CustomerListRow, ByVal action As DataRowAction)
            MyBase.New
            Me.eventRow = row
            Me.eventAction = action
        End Sub
        
        Public ReadOnly Property Row As CustomerListRow
            Get
                Return Me.eventRow
            End Get
        End Property
        
        Public ReadOnly Property Action As DataRowAction
            Get
                Return Me.eventAction
            End Get
        End Property
    End Class
    
    Public Class OrderTotalsDataTable
        Inherits DataTable
        Implements System.Collections.IEnumerable
        
        Private columnEmployeeID As DataColumn
        
        Private columnCustomerID As DataColumn
        
        Private columnOrderID As DataColumn
        
        Private columnOrderDate As DataColumn
        
        Private columnSubtotal As DataColumn
        
        Friend Sub New()
            MyBase.New("OrderTotals")
            Me.InitClass
        End Sub
        
        <System.ComponentModel.Browsable(false)>  _
        Public ReadOnly Property Count As Integer
            Get
                Return Me.Rows.Count
            End Get
        End Property
        
        Friend ReadOnly Property EmployeeIDColumn As DataColumn
            Get
                Return Me.columnEmployeeID
            End Get
        End Property
        
        Friend ReadOnly Property CustomerIDColumn As DataColumn
            Get
                Return Me.columnCustomerID
            End Get
        End Property
        
        Friend ReadOnly Property OrderIDColumn As DataColumn
            Get
                Return Me.columnOrderID
            End Get
        End Property
        
        Friend ReadOnly Property OrderDateColumn As DataColumn
            Get
                Return Me.columnOrderDate
            End Get
        End Property
        
        Friend ReadOnly Property SubtotalColumn As DataColumn
            Get
                Return Me.columnSubtotal
            End Get
        End Property
        
        Public Default ReadOnly Property Item(ByVal index As Integer) As OrderTotalsRow
            Get
                Return CType(Me.Rows(index),OrderTotalsRow)
            End Get
        End Property
        
        Public Event OrderTotalsRowChanged As OrderTotalsRowChangeEventHandler
        
        Public Event OrderTotalsRowChanging As OrderTotalsRowChangeEventHandler
        
        Public Event OrderTotalsRowDeleted As OrderTotalsRowChangeEventHandler
        
        Public Event OrderTotalsRowDeleting As OrderTotalsRowChangeEventHandler
        
        Public Overloads Sub AddOrderTotalsRow(ByVal row As OrderTotalsRow)
            Me.Rows.Add(row)
        End Sub
        
        Public Overloads Function AddOrderTotalsRow(ByVal EmployeeID As Integer, ByVal CustomerID As String, ByVal OrderID As Integer, ByVal OrderDate As Date, ByVal Subtotal As Decimal) As OrderTotalsRow
            Dim rowOrderTotalsRow As OrderTotalsRow = CType(Me.NewRow,OrderTotalsRow)
            rowOrderTotalsRow.ItemArray = New Object() {EmployeeID, CustomerID, OrderID, OrderDate, Subtotal}
            Me.Rows.Add(rowOrderTotalsRow)
            Return rowOrderTotalsRow
        End Function
        
        Public Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
            Return Me.Rows.GetEnumerator
        End Function
        
        Private Sub InitClass()
            Me.columnEmployeeID = New DataColumn("EmployeeID", GetType(System.Int32), "", System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnEmployeeID)
            Me.columnCustomerID = New DataColumn("CustomerID", GetType(System.String), "", System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnCustomerID)
            Me.columnOrderID = New DataColumn("OrderID", GetType(System.Int32), "", System.Data.MappingType.Element)
            Me.columnOrderID.AllowDBNull = false
            Me.Columns.Add(Me.columnOrderID)
            Me.columnOrderDate = New DataColumn("OrderDate", GetType(System.DateTime), "", System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnOrderDate)
            Me.columnSubtotal = New DataColumn("Subtotal", GetType(System.Decimal), "", System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnSubtotal)
        End Sub
        
        Public Function NewOrderTotalsRow() As OrderTotalsRow
            Return CType(Me.NewRow,OrderTotalsRow)
        End Function
        
        Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
            'We need to ensure that all Rows in the tabled are typed rows.
            'Table calls newRow whenever it needs to create a row.
            'So the following conditions are covered by Row newRow(Record record)
            '* Cursor calls table.addRecord(record) 
            '* table.addRow(object[] values) calls newRow(record)    
            Return New OrderTotalsRow(builder)
        End Function
        
        Protected Overrides Function GetRowType() As System.Type
            Return GetType(OrderTotalsRow)
        End Function
        
        Protected Overrides Sub OnRowChanged(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanged(e)
            If (Not (Me.OrderTotalsRowChangedEvent) Is Nothing) Then
                RaiseEvent OrderTotalsRowChanged(Me, New OrderTotalsRowChangeEvent(CType(e.Row,OrderTotalsRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowChanging(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanging(e)
            If (Not (Me.OrderTotalsRowChangingEvent) Is Nothing) Then
                RaiseEvent OrderTotalsRowChanging(Me, New OrderTotalsRowChangeEvent(CType(e.Row,OrderTotalsRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleted(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleted(e)
            If (Not (Me.OrderTotalsRowDeletedEvent) Is Nothing) Then
                RaiseEvent OrderTotalsRowDeleted(Me, New OrderTotalsRowChangeEvent(CType(e.Row,OrderTotalsRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleting(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleting(e)
            If (Not (Me.OrderTotalsRowDeletingEvent) Is Nothing) Then
                RaiseEvent OrderTotalsRowDeleting(Me, New OrderTotalsRowChangeEvent(CType(e.Row,OrderTotalsRow), e.Action))
            End If
        End Sub
        
        Public Sub RemoveOrderTotalsRow(ByVal row As OrderTotalsRow)
            Me.Rows.Remove(row)
        End Sub
    End Class
    
    Public Class OrderTotalsRow
        Inherits DataRow
        
        Private tableOrderTotals As OrderTotalsDataTable
        
        Friend Sub New(ByVal rb As DataRowBuilder)
            MyBase.New(rb)
            Me.tableOrderTotals = CType(Me.Table,OrderTotalsDataTable)
        End Sub
        
        Public Property EmployeeID As Integer
            Get
                Try 
                    Return CType(Me(Me.tableOrderTotals.EmployeeIDColumn),Integer)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderTotals.EmployeeIDColumn) = value
            End Set
        End Property
        
        Public Property CustomerID As String
            Get
                Try 
                    Return CType(Me(Me.tableOrderTotals.CustomerIDColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderTotals.CustomerIDColumn) = value
            End Set
        End Property
        
        Public Property OrderID As Integer
            Get
                Return CType(Me(Me.tableOrderTotals.OrderIDColumn),Integer)
            End Get
            Set
                Me(Me.tableOrderTotals.OrderIDColumn) = value
            End Set
        End Property
        
        Public Property OrderDate As Date
            Get
                Try 
                    Return CType(Me(Me.tableOrderTotals.OrderDateColumn),Date)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderTotals.OrderDateColumn) = value
            End Set
        End Property
        
        Public Property Subtotal As Decimal
            Get
                Try 
                    Return CType(Me(Me.tableOrderTotals.SubtotalColumn),Decimal)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderTotals.SubtotalColumn) = value
            End Set
        End Property
        
        Public Function IsEmployeeIDNull() As Boolean
            Return Me.IsNull(Me.tableOrderTotals.EmployeeIDColumn)
        End Function
        
        Public Sub SetEmployeeIDNull()
            Me(Me.tableOrderTotals.EmployeeIDColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsCustomerIDNull() As Boolean
            Return Me.IsNull(Me.tableOrderTotals.CustomerIDColumn)
        End Function
        
        Public Sub SetCustomerIDNull()
            Me(Me.tableOrderTotals.CustomerIDColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsOrderDateNull() As Boolean
            Return Me.IsNull(Me.tableOrderTotals.OrderDateColumn)
        End Function
        
        Public Sub SetOrderDateNull()
            Me(Me.tableOrderTotals.OrderDateColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsSubtotalNull() As Boolean
            Return Me.IsNull(Me.tableOrderTotals.SubtotalColumn)
        End Function
        
        Public Sub SetSubtotalNull()
            Me(Me.tableOrderTotals.SubtotalColumn) = System.Convert.DBNull
        End Sub
    End Class
    
    Public Class OrderTotalsRowChangeEvent
        Inherits EventArgs
        
        Private eventRow As OrderTotalsRow
        
        Private eventAction As System.Data.DataRowAction
        
        Public Sub New(ByVal row As OrderTotalsRow, ByVal action As DataRowAction)
            MyBase.New
            Me.eventRow = row
            Me.eventAction = action
        End Sub
        
        Public ReadOnly Property Row As OrderTotalsRow
            Get
                Return Me.eventRow
            End Get
        End Property
        
        Public ReadOnly Property Action As DataRowAction
            Get
                Return Me.eventAction
            End Get
        End Property
    End Class
End Class