study.vb

来自「Source code for VB.NET book - Chapter 6」· VB 代码 · 共 1,504 行 · 第 1/4 页

                    ByVal Notes As String,  _
                    ByVal ReportsTo As Integer,  _
                    ByVal PhotoPath As String) As EmployeesRow
            Dim rowEmployeesRow As EmployeesRow = CType(Me.NewRow,EmployeesRow)
            rowEmployeesRow.ItemArray = New Object() {Nothing, LastName, FirstName, Title, TitleOfCourtesy, BirthDate, HireDate, Address, City, _Region, PostalCode, Country, HomePhone, Extension, Photo, Notes, ReportsTo, PhotoPath}
            Me.Rows.Add(rowEmployeesRow)
            Return rowEmployeesRow
        End Function
        
        Public Function FindByEmployeeID(ByVal EmployeeID As Integer) As EmployeesRow
            Return CType(Me.Rows.Find(New Object() {EmployeeID}),EmployeesRow)
        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 EmployeesDataTable = CType(MyBase.Clone,EmployeesDataTable)
            cln.InitVars
            Return cln
        End Function
        
        Protected Overrides Function CreateInstance() As DataTable
            Return New EmployeesDataTable
        End Function
        
        Friend Sub InitVars()
            Me.columnEmployeeID = Me.Columns("EmployeeID")
            Me.columnLastName = Me.Columns("LastName")
            Me.columnFirstName = Me.Columns("FirstName")
            Me.columnTitle = Me.Columns("Title")
            Me.columnTitleOfCourtesy = Me.Columns("TitleOfCourtesy")
            Me.columnBirthDate = Me.Columns("BirthDate")
            Me.columnHireDate = Me.Columns("HireDate")
            Me.columnAddress = Me.Columns("Address")
            Me.columnCity = Me.Columns("City")
            Me.column_Region = Me.Columns("Region")
            Me.columnPostalCode = Me.Columns("PostalCode")
            Me.columnCountry = Me.Columns("Country")
            Me.columnHomePhone = Me.Columns("HomePhone")
            Me.columnExtension = Me.Columns("Extension")
            Me.columnPhoto = Me.Columns("Photo")
            Me.columnNotes = Me.Columns("Notes")
            Me.columnReportsTo = Me.Columns("ReportsTo")
            Me.columnPhotoPath = Me.Columns("PhotoPath")
        End Sub
        
        Private Sub InitClass()
            Me.columnEmployeeID = New DataColumn("EmployeeID", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnEmployeeID)
            Me.columnLastName = New DataColumn("LastName", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnLastName)
            Me.columnFirstName = New DataColumn("FirstName", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnFirstName)
            Me.columnTitle = New DataColumn("Title", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnTitle)
            Me.columnTitleOfCourtesy = New DataColumn("TitleOfCourtesy", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnTitleOfCourtesy)
            Me.columnBirthDate = New DataColumn("BirthDate", GetType(System.DateTime), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnBirthDate)
            Me.columnHireDate = New DataColumn("HireDate", GetType(System.DateTime), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnHireDate)
            Me.columnAddress = New DataColumn("Address", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnAddress)
            Me.columnCity = New DataColumn("City", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnCity)
            Me.column_Region = New DataColumn("Region", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.column_Region)
            Me.columnPostalCode = New DataColumn("PostalCode", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnPostalCode)
            Me.columnCountry = New DataColumn("Country", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnCountry)
            Me.columnHomePhone = New DataColumn("HomePhone", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnHomePhone)
            Me.columnExtension = New DataColumn("Extension", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnExtension)
            Me.columnPhoto = New DataColumn("Photo", GetType(System.Byte()), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnPhoto)
            Me.columnNotes = New DataColumn("Notes", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnNotes)
            Me.columnReportsTo = New DataColumn("ReportsTo", GetType(System.Int32), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnReportsTo)
            Me.columnPhotoPath = New DataColumn("PhotoPath", GetType(System.String), Nothing, System.Data.MappingType.Element)
            Me.Columns.Add(Me.columnPhotoPath)
            Me.Constraints.Add(New UniqueConstraint("Constraint1", New DataColumn() {Me.columnEmployeeID}, true))
            Me.columnEmployeeID.AutoIncrement = true
            Me.columnEmployeeID.AllowDBNull = false
            Me.columnEmployeeID.ReadOnly = true
            Me.columnEmployeeID.Unique = true
            Me.columnLastName.AllowDBNull = false
            Me.columnFirstName.AllowDBNull = false
        End Sub
        
        Public Function NewEmployeesRow() As EmployeesRow
            Return CType(Me.NewRow,EmployeesRow)
        End Function
        
        Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
            Return New EmployeesRow(builder)
        End Function
        
        Protected Overrides Function GetRowType() As System.Type
            Return GetType(EmployeesRow)
        End Function
        
        Protected Overrides Sub OnRowChanged(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanged(e)
            If (Not (Me.EmployeesRowChangedEvent) Is Nothing) Then
                RaiseEvent EmployeesRowChanged(Me, New EmployeesRowChangeEvent(CType(e.Row,EmployeesRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowChanging(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowChanging(e)
            If (Not (Me.EmployeesRowChangingEvent) Is Nothing) Then
                RaiseEvent EmployeesRowChanging(Me, New EmployeesRowChangeEvent(CType(e.Row,EmployeesRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleted(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleted(e)
            If (Not (Me.EmployeesRowDeletedEvent) Is Nothing) Then
                RaiseEvent EmployeesRowDeleted(Me, New EmployeesRowChangeEvent(CType(e.Row,EmployeesRow), e.Action))
            End If
        End Sub
        
        Protected Overrides Sub OnRowDeleting(ByVal e As DataRowChangeEventArgs)
            MyBase.OnRowDeleting(e)
            If (Not (Me.EmployeesRowDeletingEvent) Is Nothing) Then
                RaiseEvent EmployeesRowDeleting(Me, New EmployeesRowChangeEvent(CType(e.Row,EmployeesRow), e.Action))
            End If
        End Sub
        
        Public Sub RemoveEmployeesRow(ByVal row As EmployeesRow)
            Me.Rows.Remove(row)
        End Sub
    End Class
    
    <System.Diagnostics.DebuggerStepThrough()>  _
    Public Class EmployeesRow
        Inherits DataRow
        
        Private tableEmployees As EmployeesDataTable
        
        Friend Sub New(ByVal rb As DataRowBuilder)
            MyBase.New(rb)
            Me.tableEmployees = CType(Me.Table,EmployeesDataTable)
        End Sub
        
        Public Property EmployeeID As Integer
            Get
                Return CType(Me(Me.tableEmployees.EmployeeIDColumn),Integer)
            End Get
            Set
                Me(Me.tableEmployees.EmployeeIDColumn) = value
            End Set
        End Property
        
        Public Property LastName As String
            Get
                Return CType(Me(Me.tableEmployees.LastNameColumn),String)
            End Get
            Set
                Me(Me.tableEmployees.LastNameColumn) = value
            End Set
        End Property
        
        Public Property FirstName As String
            Get
                Return CType(Me(Me.tableEmployees.FirstNameColumn),String)
            End Get
            Set
                Me(Me.tableEmployees.FirstNameColumn) = value
            End Set
        End Property
        
        Public Property Title As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.TitleColumn),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.tableEmployees.TitleColumn) = value
            End Set
        End Property
        
        Public Property TitleOfCourtesy As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.TitleOfCourtesyColumn),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.tableEmployees.TitleOfCourtesyColumn) = value
            End Set
        End Property
        
        Public Property BirthDate As Date
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.BirthDateColumn),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.tableEmployees.BirthDateColumn) = value
            End Set
        End Property
        
        Public Property HireDate As Date
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.HireDateColumn),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.tableEmployees.HireDateColumn) = value
            End Set
        End Property
        
        Public Property Address As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.AddressColumn),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.tableEmployees.AddressColumn) = value
            End Set
        End Property
        
        Public Property City As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.CityColumn),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.tableEmployees.CityColumn) = value
            End Set
        End Property
        
        Public Property _Region As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees._RegionColumn),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.tableEmployees._RegionColumn) = value
            End Set
        End Property
        
        Public Property PostalCode As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.PostalCodeColumn),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.tableEmployees.PostalCodeColumn) = value
            End Set
        End Property
        
        Public Property Country As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.CountryColumn),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.tableEmployees.CountryColumn) = value
            End Set
        End Property
        
        Public Property HomePhone As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.HomePhoneColumn),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.tableEmployees.HomePhoneColumn) = value
            End Set
        End Property
        
        Public Property Extension As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.ExtensionColumn),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.tableEmployees.ExtensionColumn) = value
            End Set
        End Property
        
        Public Property Photo As Byte()
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.PhotoColumn),Byte())
                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.tableEmployees.PhotoColumn) = value
            End Set
        End Property
        
        Public Property Notes As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.NotesColumn),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.tableEmployees.NotesColumn) = value
            End Set
        End Property
        
        Public Property ReportsTo As Integer
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.ReportsToColumn),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.tableEmployees.ReportsToColumn) = value
            End Set
        End Property
        
        Public Property PhotoPath As String
            Get
                Try 
                    Return CType(Me(Me.tableEmployees.PhotoPathColumn),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.tableEmployees.PhotoPathColumn) = value
            End Set
        End Property
        
        Public Function IsTitleNull() As Boolean
            Return Me.IsNull(Me.tableEmployees.TitleColumn)
        End Function