R
Rob Meade
Hi all,
I've tried to use the above to make me class and collection class
enumerable - but I dont seem to be having much success.
I was wondering if my problem is because the ArrayList is zero based where
as when I run the code, the MoveNext gets triggered setting the
currentPosition to 1 - (thus I've set it to -1), but it still doesn't work.
The 'GuestbookEntry' class is definately being populated, and as far as I
can see being added to _guestbook, my only problem seems to be when I try to
put this back out.
The 'collection' class is as follows:
Imports Microsoft.VisualBasic
Imports System.Data.SqlClient
Public Class Guestbook
Implements IEnumerable, IEnumerator
#Region " Class Variables "
' class variables
Private _guestbook As ArrayList
Private _currentPosition As Integer
#End Region
#Region " Instantiate "
' instantiate
Public Sub New()
' create a new instance of our object
_guestbook = New ArrayList
_currentPosition = -1
End Sub
#End Region
#Region " Properties "
' properties
#End Region
#Region " Methods "
' methods
Public Function GetAuthorisedEntries() As Boolean
' declare variables
Dim Result As Boolean
Dim Connection As SqlConnection
Dim Command As SqlCommand
Dim Reader As SqlDataReader
Dim GuestbookEntry As GuestbookEntry
' exception handling
Try
' create and open our connection object
Connection = New
SqlConnection(ConfigurationManager.ConnectionStrings("AidenMeade").ConnectionString)
Connection.Open()
' create and define our command object
Command = New SqlCommand()
Command.CommandType = Data.CommandType.StoredProcedure
Command.CommandText = "getGuestbookEntries"
Command.Connection = Connection
' execute
Reader = Command.ExecuteReader()
' check that we have return some data
If Reader.HasRows Then
' iterate
Do While Reader.Read
' create a new instance of our object
GuestbookEntry = New GuestbookEntry(Reader("EntryID"),
Reader("EntryDetail").ToString, Reader("EntryName").ToString,
CType(Reader("EntryDateTime"), Date))
' add guestbook entry to collection
Me._guestbook.Add(GuestbookEntry)
Loop
' set result
Result = True
Else
' set result
Result = False
End If
' tidy up
Reader.Close()
Reader = Nothing
Command.Dispose()
Command = Nothing
Connection.Close()
Connection = Nothing
Catch ex As Exception
' TODO: Error handling
' tidy up
If Reader Is Nothing = False Then
Reader.Close()
Reader = Nothing
End If
If Command Is Nothing = False Then
Command.Dispose()
Command = Nothing
End If
If Connection Is Nothing = False Then
Connection.Close()
Connection = Nothing
End If
End Try
' return result
Return Result
End Function
#End Region
Public Function GetEnumerator() As System.Collections.IEnumerator
Implements System.Collections.IEnumerable.GetEnumerator
Return Me
End Function
Public ReadOnly Property Current() As Object Implements
System.Collections.IEnumerator.Current
Get
Return _guestbook(_currentPosition)
End Get
End Property
Public Function MoveNext() As Boolean Implements
System.Collections.IEnumerator.MoveNext
_currentPosition += 1
End Function
Public Sub Reset() Implements System.Collections.IEnumerator.Reset
_currentPosition = -1
End Sub
End Class
The code I'm using to pull the info back out is on the code behind page for
my web page:
' declare variables
Dim Guestbook As Guestbook
Dim GuestbookEntry As GuestbookEntry
' create a new instance of our object
Guestbook = New Guestbook
' get guestbook entries
Guestbook.GetAuthorisedEntries()
' iterate
For Each GuestbookEntry In Guestbook
Dim row As TableRow
Dim cell As TableCell
row = New TableRow
cell = New TableCell
cell.Text = GuestbookEntry.Name
row.Cells.Add(cell)
tblGuestbookItems.Rows.Add(row)
Next
I'd really appreciate any help - I *think* the problem is in the
GetEnumerator() function, but I thought returning 'me' was correct.
Regards
Rob
I've tried to use the above to make me class and collection class
enumerable - but I dont seem to be having much success.
I was wondering if my problem is because the ArrayList is zero based where
as when I run the code, the MoveNext gets triggered setting the
currentPosition to 1 - (thus I've set it to -1), but it still doesn't work.
The 'GuestbookEntry' class is definately being populated, and as far as I
can see being added to _guestbook, my only problem seems to be when I try to
put this back out.
The 'collection' class is as follows:
Imports Microsoft.VisualBasic
Imports System.Data.SqlClient
Public Class Guestbook
Implements IEnumerable, IEnumerator
#Region " Class Variables "
' class variables
Private _guestbook As ArrayList
Private _currentPosition As Integer
#End Region
#Region " Instantiate "
' instantiate
Public Sub New()
' create a new instance of our object
_guestbook = New ArrayList
_currentPosition = -1
End Sub
#End Region
#Region " Properties "
' properties
#End Region
#Region " Methods "
' methods
Public Function GetAuthorisedEntries() As Boolean
' declare variables
Dim Result As Boolean
Dim Connection As SqlConnection
Dim Command As SqlCommand
Dim Reader As SqlDataReader
Dim GuestbookEntry As GuestbookEntry
' exception handling
Try
' create and open our connection object
Connection = New
SqlConnection(ConfigurationManager.ConnectionStrings("AidenMeade").ConnectionString)
Connection.Open()
' create and define our command object
Command = New SqlCommand()
Command.CommandType = Data.CommandType.StoredProcedure
Command.CommandText = "getGuestbookEntries"
Command.Connection = Connection
' execute
Reader = Command.ExecuteReader()
' check that we have return some data
If Reader.HasRows Then
' iterate
Do While Reader.Read
' create a new instance of our object
GuestbookEntry = New GuestbookEntry(Reader("EntryID"),
Reader("EntryDetail").ToString, Reader("EntryName").ToString,
CType(Reader("EntryDateTime"), Date))
' add guestbook entry to collection
Me._guestbook.Add(GuestbookEntry)
Loop
' set result
Result = True
Else
' set result
Result = False
End If
' tidy up
Reader.Close()
Reader = Nothing
Command.Dispose()
Command = Nothing
Connection.Close()
Connection = Nothing
Catch ex As Exception
' TODO: Error handling
' tidy up
If Reader Is Nothing = False Then
Reader.Close()
Reader = Nothing
End If
If Command Is Nothing = False Then
Command.Dispose()
Command = Nothing
End If
If Connection Is Nothing = False Then
Connection.Close()
Connection = Nothing
End If
End Try
' return result
Return Result
End Function
#End Region
Public Function GetEnumerator() As System.Collections.IEnumerator
Implements System.Collections.IEnumerable.GetEnumerator
Return Me
End Function
Public ReadOnly Property Current() As Object Implements
System.Collections.IEnumerator.Current
Get
Return _guestbook(_currentPosition)
End Get
End Property
Public Function MoveNext() As Boolean Implements
System.Collections.IEnumerator.MoveNext
_currentPosition += 1
End Function
Public Sub Reset() Implements System.Collections.IEnumerator.Reset
_currentPosition = -1
End Sub
End Class
The code I'm using to pull the info back out is on the code behind page for
my web page:
' declare variables
Dim Guestbook As Guestbook
Dim GuestbookEntry As GuestbookEntry
' create a new instance of our object
Guestbook = New Guestbook
' get guestbook entries
Guestbook.GetAuthorisedEntries()
' iterate
For Each GuestbookEntry In Guestbook
Dim row As TableRow
Dim cell As TableCell
row = New TableRow
cell = New TableCell
cell.Text = GuestbookEntry.Name
row.Cells.Add(cell)
tblGuestbookItems.Rows.Add(row)
Next
I'd really appreciate any help - I *think* the problem is in the
GetEnumerator() function, but I thought returning 'me' was correct.
Regards
Rob
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