ds1.vb

抽奖的模拟过程！自己写的

        Public Event AudienceRowDeleted As AudienceRowChangeEventHandler
        
        Public Event AudienceRowDeleting As AudienceRowChangeEventHandler
        
        Public Overloads Sub AddAudienceRow(ByVal row As AudienceRow)
            Me.Rows.Add(row)
        End Sub
        
        Public Overloads Function AddAudienceRow(ByVal Number As Short, ByVal RowId As Short, ByVal Type As String) As AudienceRow
            Dim rowAudienceRow As AudienceRow = CType(Me.NewRow,AudienceRow)
            rowAudienceRow.ItemArray = New Object() {Nothing, Number, RowId, Type}
            Me.Rows.Add(rowAudienceRow)
            Return rowAudienceRow
        End Function
        
        Public Function FindByID1(ByVal ID1 As Integer) As AudienceRow
            Return CType(Me.Rows.Find(New Object() {ID1}),AudienceRow)
        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 AudienceDataTable = CType(MyBase.Clone,AudienceDataTable)
            cln.InitVars
            Return cln
        End Function
        
        Protected Overrides Function CreateInstance() As DataTable
            Return New AudienceDataTable
        End Function
        
        Friend Sub InitVars()
            Me.columnID1 = Me.Columns("ID1")
            Me.columnNumber = Me.Columns("Number")
            Me.columnRowId = Me.Columns("RowId")
            Me.columnType = Me.Columns("Type")
        End Sub
        
        Private Sub InitClass()
            Me.columnID1 = New DataColumn("ID1", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnID1)
            Me.columnNumber = New DataColumn("Number", GetType(System.Int16), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnNumber)
            Me.columnRowId = New DataColumn("RowId", GetType(System.Int16), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnRowId)
            Me.columnType = New DataColumn("Type", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnType)
            Me.Constraints.Add(New UniqueConstraint("Constraint1", New DataColumn() {Me.columnID1}, true))
            Me.columnID1.AutoIncrement = true
            Me.columnID1.AllowDBNull = false
            Me.columnID1.Unique = true
        End Sub
        
        Public Function NewAudienceRow() As AudienceRow
            Return CType(Me.NewRow,AudienceRow)
        End Function
        
        Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
            Return New AudienceRow(builder)
        End Function
        
        Protected Overrides Function GetRowType() As System.Type
            Return GetType(AudienceRow)
        End Function
        
        Protected Overrides Sub OnRowChanged(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanged(e)
            If (Not (Me.AudienceRowChangedEvent) Is Nothing) Then
                RaiseEvent AudienceRowChanged(Me, New AudienceRowChangeEvent(CType(e.Row,AudienceRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowChanging(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanging(e)
            If (Not (Me.AudienceRowChangingEvent) Is Nothing) Then
                RaiseEvent AudienceRowChanging(Me, New AudienceRowChangeEvent(CType(e.Row,AudienceRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleted(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleted(e)
            If (Not (Me.AudienceRowDeletedEvent) Is Nothing) Then
                RaiseEvent AudienceRowDeleted(Me, New AudienceRowChangeEvent(CType(e.Row,AudienceRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleting(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleting(e)
            If (Not (Me.AudienceRowDeletingEvent) Is Nothing) Then
                RaiseEvent AudienceRowDeleting(Me, New AudienceRowChangeEvent(CType(e.Row,AudienceRow), e.Action))
            End If
        End Sub
        
        Public Sub RemoveAudienceRow(ByVal row As AudienceRow)
            Me.Rows.Remove(row)
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class AudienceRow
        Inherits DataRow
        
        Private tableAudience As AudienceDataTable
        
        Friend Sub New(ByVal rb As DataRowBuilder)
            MyBase.New(rb)
            Me.tableAudience = CType(Me.Table,AudienceDataTable)
        End Sub
        
        Public Property ID1 As Integer
            Get
                Return CType(Me(Me.tableAudience.ID1Column),Integer)
            End Get
            Set
                Me(Me.tableAudience.ID1Column) = value
            End Set
        End Property
        
        Public Property Number As Short
            Get
                Try 
                    Return CType(Me(Me.tableAudience.NumberColumn),Short)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableAudience.NumberColumn) = value
            End Set
        End Property
        
        Public Property RowId As Short
            Get
                Try 
                    Return CType(Me(Me.tableAudience.RowIdColumn),Short)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableAudience.RowIdColumn) = value
            End Set
        End Property
        
        Public Property Type As String
            Get
                Try 
                    Return CType(Me(Me.tableAudience.TypeColumn),String)
                Catch e As InvalidCastException
                    Throw New StrongTypingException("Cannot get value because it is DBNull.", e)
                End Try
            End Get
            Set
                Me(Me.tableAudience.TypeColumn) = value
            End Set
        End Property
        
        Public Function IsNumberNull() As Boolean
            Return Me.IsNull(Me.tableAudience.NumberColumn)
        End Function
        
        Public Sub SetNumberNull()
            Me(Me.tableAudience.NumberColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsRowIdNull() As Boolean
            Return Me.IsNull(Me.tableAudience.RowIdColumn)
        End Function
        
        Public Sub SetRowIdNull()
            Me(Me.tableAudience.RowIdColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsTypeNull() As Boolean
            Return Me.IsNull(Me.tableAudience.TypeColumn)
        End Function
        
        Public Sub SetTypeNull()
            Me(Me.tableAudience.TypeColumn) = System.Convert.DBNull
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class AudienceRowChangeEvent
        Inherits EventArgs
        
        Private eventRow As AudienceRow
        
        Private eventAction As DataRowAction
        
        Public Sub New(ByVal row As AudienceRow, ByVal action As DataRowAction)
            MyBase.New
            Me.eventRow = row
            Me.eventAction = action
        End Sub
        
        Public ReadOnly Property Row As AudienceRow
            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