dataset1.vb

Visual.Basic.NET实用编程百例-47.6M.zip

                Try 
                    Return CType(Me(Me.tableOrderDetail.DiscountColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("无法获取值，因为它是 DBNull。", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderDetail.DiscountColumn) = value
            End Set
        End Property
        
        Public Property OrderID As String
            Get
                Return CType(Me(Me.tableOrderDetail.OrderIDColumn),String)
            End Get
            Set
                Me(Me.tableOrderDetail.OrderIDColumn) = value
            End Set
        End Property
        
        Public Property Quantity As String
            Get
                Try 
                    Return CType(Me(Me.tableOrderDetail.QuantityColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("无法获取值，因为它是 DBNull。", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderDetail.QuantityColumn) = value
            End Set
        End Property
        
        Public Property UnitPrice As String
            Get
                Try 
                    Return CType(Me(Me.tableOrderDetail.UnitPriceColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("无法获取值，因为它是 DBNull。", e)
                End Try
            End Get
            Set
                Me(Me.tableOrderDetail.UnitPriceColumn) = value
            End Set
        End Property
        
        Public Function IsDiscountNull() As Boolean
            Return Me.IsNull(Me.tableOrderDetail.DiscountColumn)
        End Function
        
        Public Sub SetDiscountNull()
            Me(Me.tableOrderDetail.DiscountColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsQuantityNull() As Boolean
            Return Me.IsNull(Me.tableOrderDetail.QuantityColumn)
        End Function
        
        Public Sub SetQuantityNull()
            Me(Me.tableOrderDetail.QuantityColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsUnitPriceNull() As Boolean
            Return Me.IsNull(Me.tableOrderDetail.UnitPriceColumn)
        End Function
        
        Public Sub SetUnitPriceNull()
            Me(Me.tableOrderDetail.UnitPriceColumn) = System.Convert.DBNull
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class OrderDetailRowChangeEvent
        Inherits EventArgs
        
        Private eventRow As OrderDetailRow
        
        Private eventAction As DataRowAction
        
        Public Sub New(ByVal row As OrderDetailRow, ByVal action As DataRowAction)
            MyBase.New
            Me.eventRow = row
            Me.eventAction = action
        End Sub
        
        Public ReadOnly Property Row As OrderDetailRow
            Get
                Return Me.eventRow
            End Get
        End Property
        
        Public ReadOnly Property Action As DataRowAction
            Get
                Return Me.eventAction
            End Get
        End Property
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class OrderDataTable
        Inherits DataTable
        Implements System.Collections.IEnumerable
        
        Private columnCustomerID As DataColumn
        
        Private columnOrderDate As DataColumn
        
        Private columnOrderID As DataColumn
        
        Friend Sub New()
            MyBase.New("Order")
            Me.InitClass
        End Sub
        
        Friend Sub New(ByVal table As DataTable)
            MyBase.New(table.TableName)
            If (table.CaseSensitive <> table.DataSet.CaseSensitive) Then
                Me.CaseSensitive = table.CaseSensitive
            End If
            If (table.Locale.ToString <> table.DataSet.Locale.ToString) Then
                Me.Locale = table.Locale
            End If
            If (table.Namespace <> table.DataSet.Namespace) Then
                Me.Namespace = table.Namespace
            End If
            Me.Prefix = table.Prefix
            Me.MinimumCapacity = table.MinimumCapacity
            Me.DisplayExpression = table.DisplayExpression
        End Sub
        
        <System.ComponentModel.Browsable(false)>  _
        Public ReadOnly Property Count As Integer
            Get
                Return Me.Rows.Count
            End Get
        End Property
        
        Friend ReadOnly Property CustomerIDColumn As DataColumn
            Get
                Return Me.columnCustomerID
            End Get
        End Property
        
        Friend ReadOnly Property OrderDateColumn As DataColumn
            Get
                Return Me.columnOrderDate
            End Get
        End Property
        
        Friend ReadOnly Property OrderIDColumn As DataColumn
            Get
                Return Me.columnOrderID
            End Get
        End Property
        
        Public Default ReadOnly Property Item(ByVal index As Integer) As OrderRow
            Get
                Return CType(Me.Rows(index),OrderRow)
            End Get
        End Property
        
        Public Event OrderRowChanged As OrderRowChangeEventHandler
        
        Public Event OrderRowChanging As OrderRowChangeEventHandler
        
        Public Event OrderRowDeleted As OrderRowChangeEventHandler
        
        Public Event OrderRowDeleting As OrderRowChangeEventHandler
        
        Public Overloads Sub AddOrderRow(ByVal row As OrderRow)
            Me.Rows.Add(row)
        End Sub
        
        Public Overloads Function AddOrderRow(ByVal CustomerID As String, ByVal OrderDate As String, ByVal OrderID As String) As OrderRow
            Dim rowOrderRow As OrderRow = CType(Me.NewRow,OrderRow)
            rowOrderRow.ItemArray = New Object() {CustomerID, OrderDate, OrderID}
            Me.Rows.Add(rowOrderRow)
            Return rowOrderRow
        End Function
        
        Public Function FindByOrderID(ByVal OrderID As String) As OrderRow
            Return CType(Me.Rows.Find(New Object() {OrderID}),OrderRow)
        End Function
        
        Public Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
            Return Me.Rows.GetEnumerator
        End Function
        
        Public Overrides Function Clone() As DataTable
            Dim cln As OrderDataTable = CType(MyBase.Clone,OrderDataTable)
            cln.InitVars
            Return cln
        End Function
        
        Protected Overrides Function CreateInstance() As DataTable
            Return New OrderDataTable
        End Function
        
        Friend Sub InitVars()
            Me.columnCustomerID = Me.Columns("CustomerID")
            Me.columnOrderDate = Me.Columns("OrderDate")
            Me.columnOrderID = Me.Columns("OrderID")
        End Sub
        
        Private Sub InitClass()
            Me.columnCustomerID = New DataColumn("CustomerID", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnCustomerID)
            Me.columnOrderDate = New DataColumn("OrderDate", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnOrderDate)
            Me.columnOrderID = New DataColumn("OrderID", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnOrderID)
            Me.Constraints.Add(New UniqueConstraint("Constraint1", New DataColumn() {Me.columnOrderID}, true))
            Me.columnOrderID.AllowDBNull = false
            Me.columnOrderID.Unique = true
        End Sub
        
        Public Function NewOrderRow() As OrderRow
            Return CType(Me.NewRow,OrderRow)
        End Function
        
        Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
            Return New OrderRow(builder)
        End Function
        
        Protected Overrides Function GetRowType() As System.Type
            Return GetType(OrderRow)
        End Function
        
        Protected Overrides Sub OnRowChanged(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanged(e)
            If (Not (Me.OrderRowChangedEvent) Is Nothing) Then
                RaiseEvent OrderRowChanged(Me, New OrderRowChangeEvent(CType(e.Row,OrderRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowChanging(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanging(e)
            If (Not (Me.OrderRowChangingEvent) Is Nothing) Then
                RaiseEvent OrderRowChanging(Me, New OrderRowChangeEvent(CType(e.Row,OrderRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleted(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleted(e)
            If (Not (Me.OrderRowDeletedEvent) Is Nothing) Then
                RaiseEvent OrderRowDeleted(Me, New OrderRowChangeEvent(CType(e.Row,OrderRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleting(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleting(e)
            If (Not (Me.OrderRowDeletingEvent) Is Nothing) Then
                RaiseEvent OrderRowDeleting(Me, New OrderRowChangeEvent(CType(e.Row,OrderRow), e.Action))
            End If
        End Sub
        
        Public Sub RemoveOrderRow(ByVal row As OrderRow)
            Me.Rows.Remove(row)
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class OrderRow
        Inherits DataRow
        
        Private tableOrder As OrderDataTable
        
        Friend Sub New(ByVal rb As DataRowBuilder)
            MyBase.New(rb)
            Me.tableOrder = CType(Me.Table,OrderDataTable)
        End Sub
        
        Public Property CustomerID As String
            Get
                Try 
                    Return CType(Me(Me.tableOrder.CustomerIDColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("无法获取值，因为它是 DBNull。", e)
                End Try
            End Get
            Set
                Me(Me.tableOrder.CustomerIDColumn) = value
            End Set
        End Property
        
        Public Property OrderDate As String
            Get
                Try 
                    Return CType(Me(Me.tableOrder.OrderDateColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("无法获取值，因为它是 DBNull。", e)
                End Try
            End Get
            Set
                Me(Me.tableOrder.OrderDateColumn) = value
            End Set
        End Property
        
        Public Property OrderID As String
            Get
                Return CType(Me(Me.tableOrder.OrderIDColumn),String)
            End Get
            Set
                Me(Me.tableOrder.OrderIDColumn) = value
            End Set
        End Property
        
        Public Function IsCustomerIDNull() As Boolean
            Return Me.IsNull(Me.tableOrder.CustomerIDColumn)
        End Function
        
        Public Sub SetCustomerIDNull()
            Me(Me.tableOrder.CustomerIDColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsOrderDateNull() As Boolean
            Return Me.IsNull(Me.tableOrder.OrderDateColumn)
        End Function
        
        Public Sub SetOrderDateNull()
            Me(Me.tableOrder.OrderDateColumn) = System.Convert.DBNull
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class OrderRowChangeEvent
        Inherits EventArgs
        
        Private eventRow As OrderRow
        
        Private eventAction As DataRowAction
        
        Public Sub New(ByVal row As OrderRow, ByVal action As DataRowAction)
            MyBase.New
            Me.eventRow = row
            Me.eventAction = action
        End Sub
        
        Public ReadOnly Property Row As OrderRow
            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