dataset1.vb

Visual Basic.net 实例入门

        Public Overloads Function AddguestbookRow(ByVal biaoti As String, ByVal content As String, ByVal Post_time As Date, ByVal username As String) As guestbookRow
            Dim rowguestbookRow As guestbookRow = CType(Me.NewRow,guestbookRow)
            rowguestbookRow.ItemArray = New Object() {biaoti, Nothing, content, Post_time, username}
            Me.Rows.Add(rowguestbookRow)
            Return rowguestbookRow
        End Function
        
        Public Function FindByBook_id(ByVal Book_id As Integer) As guestbookRow
            Return CType(Me.Rows.Find(New Object() {Book_id}),guestbookRow)
        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 guestbookDataTable = CType(MyBase.Clone,guestbookDataTable)
            cln.InitVars
            Return cln
        End Function
        
        Protected Overrides Function CreateInstance() As DataTable
            Return New guestbookDataTable
        End Function
        
        Friend Sub InitVars()
            Me.columnbiaoti = Me.Columns("biaoti")
            Me.columnBook_id = Me.Columns("Book_id")
            Me.columncontent = Me.Columns("content")
            Me.columnPost_time = Me.Columns("Post_time")
            Me.columnusername = Me.Columns("username")
        End Sub
        
        Private Sub InitClass()
            Me.columnbiaoti = New DataColumn("biaoti", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnbiaoti)
            Me.columnBook_id = New DataColumn("Book_id", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnBook_id)
            Me.columncontent = New DataColumn("content", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columncontent)
            Me.columnPost_time = New DataColumn("Post_time", GetType(System.DateTime), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnPost_time)
            Me.columnusername = New DataColumn("username", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnusername)
            Me.Constraints.Add(New UniqueConstraint("Constraint1", New DataColumn() {Me.columnBook_id}, true))
            Me.columnBook_id.AutoIncrement = true
            Me.columnBook_id.AllowDBNull = false
            Me.columnBook_id.Unique = true
        End Sub
        
        Public Function NewguestbookRow() As guestbookRow
            Return CType(Me.NewRow,guestbookRow)
        End Function
        
        Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
            Return New guestbookRow(builder)
        End Function
        
        Protected Overrides Function GetRowType() As System.Type
            Return GetType(guestbookRow)
        End Function
        
        Protected Overrides Sub OnRowChanged(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanged(e)
            If (Not (Me.guestbookRowChangedEvent) Is Nothing) Then
                RaiseEvent guestbookRowChanged(Me, New guestbookRowChangeEvent(CType(e.Row,guestbookRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowChanging(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanging(e)
            If (Not (Me.guestbookRowChangingEvent) Is Nothing) Then
                RaiseEvent guestbookRowChanging(Me, New guestbookRowChangeEvent(CType(e.Row,guestbookRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleted(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleted(e)
            If (Not (Me.guestbookRowDeletedEvent) Is Nothing) Then
                RaiseEvent guestbookRowDeleted(Me, New guestbookRowChangeEvent(CType(e.Row,guestbookRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleting(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleting(e)
            If (Not (Me.guestbookRowDeletingEvent) Is Nothing) Then
                RaiseEvent guestbookRowDeleting(Me, New guestbookRowChangeEvent(CType(e.Row,guestbookRow), e.Action))
            End If
        End Sub
        
        Public Sub RemoveguestbookRow(ByVal row As guestbookRow)
            Me.Rows.Remove(row)
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class guestbookRow
        Inherits DataRow
        
        Private tableguestbook As guestbookDataTable
        
        Friend Sub New(ByVal rb As DataRowBuilder)
            MyBase.New(rb)
            Me.tableguestbook = CType(Me.Table,guestbookDataTable)
        End Sub
        
        Public Property biaoti As String
            Get
                Try 
                    Return CType(Me(Me.tableguestbook.biaotiColumn),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.tableguestbook.biaotiColumn) = value
            End Set
        End Property
        
        Public Property Book_id As Integer
            Get
                Return CType(Me(Me.tableguestbook.Book_idColumn),Integer)
            End Get
            Set
                Me(Me.tableguestbook.Book_idColumn) = value
            End Set
        End Property
        
        Public Property content As String
            Get
                Try 
                    Return CType(Me(Me.tableguestbook.contentColumn),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.tableguestbook.contentColumn) = value
            End Set
        End Property
        
        Public Property Post_time As Date
            Get
                Try 
                    Return CType(Me(Me.tableguestbook.Post_timeColumn),Date)
                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.tableguestbook.Post_timeColumn) = value
            End Set
        End Property
        
        Public Property username As String
            Get
                Try 
                    Return CType(Me(Me.tableguestbook.usernameColumn),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.tableguestbook.usernameColumn) = value
            End Set
        End Property
        
        Public Function IsbiaotiNull() As Boolean
            Return Me.IsNull(Me.tableguestbook.biaotiColumn)
        End Function
        
        Public Sub SetbiaotiNull()
            Me(Me.tableguestbook.biaotiColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IscontentNull() As Boolean
            Return Me.IsNull(Me.tableguestbook.contentColumn)
        End Function
        
        Public Sub SetcontentNull()
            Me(Me.tableguestbook.contentColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsPost_timeNull() As Boolean
            Return Me.IsNull(Me.tableguestbook.Post_timeColumn)
        End Function
        
        Public Sub SetPost_timeNull()
            Me(Me.tableguestbook.Post_timeColumn) = System.Convert.DBNull
        End Sub
        
        Public Function IsusernameNull() As Boolean
            Return Me.IsNull(Me.tableguestbook.usernameColumn)
        End Function
        
        Public Sub SetusernameNull()
            Me(Me.tableguestbook.usernameColumn) = System.Convert.DBNull
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class guestbookRowChangeEvent
        Inherits EventArgs
        
        Private eventRow As guestbookRow
        
        Private eventAction As DataRowAction
        
        Public Sub New(ByVal row As guestbookRow, ByVal action As DataRowAction)
            MyBase.New
            Me.eventRow = row
            Me.eventAction = action
        End Sub
        
        Public ReadOnly Property Row As guestbookRow
            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