classes.vb

编程之道VB.NETt程序设计入门-589M.zip

Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.SqlTypes

Imports Nozama.General

Namespace Nozama.DataAccess

    Public Class Classes
        Implements IDisposable

        Private dsCommand As SqlDataAdapter

        Public Sub New()
            MyBase.New()

            dsCommand = New SqlDataAdapter()

            dsCommand.SelectCommand = New SqlCommand()
            dsCommand.SelectCommand.Connection = New SqlConnection(Settings.ConnectionString)

            dsCommand.TableMappings.Add("Table", ClassData.CLASSES_TABLE)
        End Sub

        Public Sub Dispose() Implements IDisposable.Dispose
            Dispose(True)
            GC.SuppressFinalize(True)
        End Sub

        Protected Overridable Sub Dispose(ByVal disposing As Boolean)
            If Not disposing Then
                Exit Sub
            End If

            If Not dsCommand Is Nothing Then
                If Not dsCommand.SelectCommand Is Nothing Then
                    If Not dsCommand.SelectCommand.Connection Is Nothing Then
                        dsCommand.SelectCommand.Connection.Dispose()
                    End If
                    dsCommand.SelectCommand.Dispose()
                End If
                dsCommand.Dispose()
                dsCommand = Nothing
            End If
        End Sub

        Public Function GetClasses() As ClassData
            Dim data As ClassData
            data = New ClassData()

            With dsCommand
                Try
                    With .SelectCommand
                        .CommandType = CommandType.Text
                        .CommandText = "SELECT * FROM Classes"
                    End With
                    .Fill(data)
                Finally
                    If Not .SelectCommand Is Nothing Then
                        If Not .SelectCommand.Connection Is Nothing Then
                            .SelectCommand.Connection.Dispose()
                        End If
                        .SelectCommand.Dispose()
                    End If
                    .Dispose()
                End Try
            End With

            Return data
        End Function

    End Class

End Namespace