myds.vb

vb 应用实例 简单应用 ddddddddddddddddddddddddddddddddd

        Public Overloads Function AddProductsRow(ByVal ProductName As String, ByVal SupplierID As Integer, ByVal parentCategoriesRowBy分类代号 As CategoriesRow, ByVal QuantityPerUnit As String, ByVal UnitPrice As Decimal, ByVal UnitsInStock As Short, ByVal UnitsOnOrder As Short, ByVal ReorderLevel As Short, ByVal Discontinued As Boolean) As ProductsRow
            Dim rowProductsRow As ProductsRow = CType(Me.NewRow,ProductsRow)
            rowProductsRow.ItemArray = New Object() {Nothing, ProductName, SupplierID, parentCategoriesRowBy分类代号(0), QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder, ReorderLevel, Discontinued}
            Me.Rows.Add(rowProductsRow)
            Return rowProductsRow
        End Function
        
        Public Function FindByProductID(ByVal ProductID As Integer) As ProductsRow
            Return CType(Me.Rows.Find(New Object() {ProductID}),ProductsRow)
        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 ProductsDataTable = CType(MyBase.Clone,ProductsDataTable)
            cln.InitVars
            Return cln
        End Function
        
        Protected Overrides Function CreateInstance() As DataTable
            Return New ProductsDataTable
        End Function
        
        Friend Sub InitVars()
            Me.columnProductID = Me.Columns("ProductID")
            Me.columnProductName = Me.Columns("ProductName")
            Me.columnSupplierID = Me.Columns("SupplierID")
            Me.columnCategoryID = Me.Columns("CategoryID")
            Me.columnQuantityPerUnit = Me.Columns("QuantityPerUnit")
            Me.columnUnitPrice = Me.Columns("UnitPrice")
            Me.columnUnitsInStock = Me.Columns("UnitsInStock")
            Me.columnUnitsOnOrder = Me.Columns("UnitsOnOrder")
            Me.columnReorderLevel = Me.Columns("ReorderLevel")
            Me.columnDiscontinued = Me.Columns("Discontinued")
        End Sub
        
        Private Sub InitClass()
            Me.columnProductID = New DataColumn("ProductID", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnProductID)
            Me.columnProductName = New DataColumn("ProductName", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnProductName)
            Me.columnSupplierID = New DataColumn("SupplierID", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnSupplierID)
            Me.columnCategoryID = New DataColumn("CategoryID", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnCategoryID)
            Me.columnQuantityPerUnit = New DataColumn("QuantityPerUnit", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnQuantityPerUnit)
            Me.columnUnitPrice = New DataColumn("UnitPrice", GetType(System.Decimal), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnUnitPrice)
            Me.columnUnitsInStock = New DataColumn("UnitsInStock", GetType(System.Int16), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnUnitsInStock)
            Me.columnUnitsOnOrder = New DataColumn("UnitsOnOrder", GetType(System.Int16), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnUnitsOnOrder)
            Me.columnReorderLevel = New DataColumn("ReorderLevel", GetType(System.Int16), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnReorderLevel)
            Me.columnDiscontinued = New DataColumn("Discontinued", GetType(System.Boolean), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnDiscontinued)
            Me.Constraints.Add(New UniqueConstraint("Constraint1", New DataColumn() {Me.columnProductID}, true))
            Me.columnProductID.AutoIncrement = true
            Me.columnProductID.AllowDBNull = false
            Me.columnProductID.ReadOnly = true
            Me.columnProductID.Unique = true
            Me.columnProductName.AllowDBNull = false
            Me.columnDiscontinued.AllowDBNull = false
        End Sub
        
        Public Function NewProductsRow() As ProductsRow
            Return CType(Me.NewRow,ProductsRow)
        End Function
        
        Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
            Return New ProductsRow(builder)
        End Function
        
        Protected Overrides Function GetRowType() As System.Type
            Return GetType(ProductsRow)
        End Function
        
        Protected Overrides Sub OnRowChanged(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanged(e)
            If (Not (Me.ProductsRowChangedEvent) Is Nothing) Then
                RaiseEvent ProductsRowChanged(Me, New ProductsRowChangeEvent(CType(e.Row,ProductsRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowChanging(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanging(e)
            If (Not (Me.ProductsRowChangingEvent) Is Nothing) Then
                RaiseEvent ProductsRowChanging(Me, New ProductsRowChangeEvent(CType(e.Row,ProductsRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleted(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleted(e)
            If (Not (Me.ProductsRowDeletedEvent) Is Nothing) Then
                RaiseEvent ProductsRowDeleted(Me, New ProductsRowChangeEvent(CType(e.Row,ProductsRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleting(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleting(e)
            If (Not (Me.ProductsRowDeletingEvent) Is Nothing) Then
                RaiseEvent ProductsRowDeleting(Me, New ProductsRowChangeEvent(CType(e.Row,ProductsRow), e.Action))
            End If
        End Sub
        
        Public Sub RemoveProductsRow(ByVal row As ProductsRow)
            Me.Rows.Remove(row)
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class ProductsRow
        Inherits DataRow
        
        Private tableProducts As ProductsDataTable
        
        Friend Sub New(ByVal rb As DataRowBuilder)
            MyBase.New(rb)
            Me.tableProducts = CType(Me.Table,ProductsDataTable)
        End Sub
        
        Public Property ProductID As Integer
            Get
                Return CType(Me(Me.tableProducts.ProductIDColumn),Integer)
            End Get
            Set
                Me(Me.tableProducts.ProductIDColumn) = value
            End Set
        End Property
        
        Public Property ProductName As String
            Get
                Return CType(Me(Me.tableProducts.ProductNameColumn),String)
            End Get
            Set
                Me(Me.tableProducts.ProductNameColumn) = value
            End Set
        End Property
        
        Public Property SupplierID As Integer
            Get
                Try 
                    Return CType(Me(Me.tableProducts.SupplierIDColumn),Integer)
                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.tableProducts.SupplierIDColumn) = value
            End Set
        End Property
        
        Public Property CategoryID As Integer
            Get
                Try 
                    Return CType(Me(Me.tableProducts.CategoryIDColumn),Integer)
                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.tableProducts.CategoryIDColumn) = value
            End Set
        End Property
        
        Public Property QuantityPerUnit As String
            Get
                Try 
                    Return CType(Me(Me.tableProducts.QuantityPerUnitColumn),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.tableProducts.QuantityPerUnitColumn) = value
            End Set
        End Property
        
        Public Property UnitPrice As Decimal
            Get
                Try 
                    Return CType(Me(Me.tableProducts.UnitPriceColumn),Decimal)
                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.tableProducts.UnitPriceColumn) = value
            End Set
        End Property
        
        Public Property UnitsInStock As Short
            Get
                Try 
                    Return CType(Me(Me.tableProducts.UnitsInStockColumn),Short)
                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.tableProducts.UnitsInStockColumn) = value
            End Set
        End Property
        
        Public Property UnitsOnOrder As Short
            Get
                Try 
                    Return CType(Me(Me.tableProducts.UnitsOnOrderColumn),Short)
                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.tableProducts.UnitsOnOrderColumn) = value
            End Set
        End Property
        
        Public Property ReorderLevel As Short
            Get
                Try 
                    Return CType(Me(Me.tableProducts.ReorderLevelColumn),Short)
                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.tableProducts.ReorderLevelColumn) = value
            End Set
        End Property
        
        Public Property Discontinued As Boolean
            Get
                Return CType(Me(Me.tableProducts.DiscontinuedColumn),Boolean)
            End Get
            Set
                Me(Me.tableProducts.DiscontinuedColumn) = value
            End Set
        End Property
        
        Public Property CategoriesRow As CategoriesRow
            Get
                Return CType(Me.GetParentRow(Me.Table.ParentRelations("分类代号")),CategoriesRow)
            End Get
            Set
                Me.SetParentRow(value, Me.Table.ParentRelations("分类代号"))
            End Set
        End Property
        
        Public Function IsSupplierIDNull() As Boolean
            Return Me.IsNull(Me.tableProducts.SupplierIDColumn)
        End Function
        
        Public Sub SetSupplierIDNull()
            Me(Me.tableProducts.SupplierIDColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsCategoryIDNull() As Boolean
            Return Me.IsNull(Me.tableProducts.CategoryIDColumn)
        End Function
        
        Public Sub SetCategoryIDNull()
            Me(Me.tableProducts.CategoryIDColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsQuantityPerUnitNull() As Boolean
            Return Me.IsNull(Me.tableProducts.QuantityPerUnitColumn)
        End Function
        
        Public Sub SetQuantityPerUnitNull()
            Me(Me.tableProducts.QuantityPerUnitColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsUnitPriceNull() As Boolean
            Return Me.IsNull(Me.tableProducts.UnitPriceColumn)
        End Function
        
        Public Sub SetUnitPriceNull()
            Me(Me.tableProducts.UnitPriceColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsUnitsInStockNull() As Boolean
            Return Me.IsNull(Me.tableProducts.UnitsInStockColumn)
        End Function
        
        Public Sub SetUnitsInStockNull()
            Me(Me.tableProducts.UnitsInStockColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsUnitsOnOrderNull() As Boolean
            Return Me.IsNull(Me.tableProducts.UnitsOnOrderColumn)
        End Function
        
        Public Sub SetUnitsOnOrderNull()
            Me(Me.tableProducts.UnitsOnOrderColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsReorderLevelNull() As Boolean
            Return Me.IsNull(Me.tableProducts.ReorderLevelColumn)
        End Function
        
        Public Sub SetReorderLevelNull()
            Me(Me.tableProducts.ReorderLevelColumn) = System.Convert.DBNull
        End Sub
    End Class