Raymond Lewallen

Link Listing - May 11, 2005

I think this can also be implemented as a mixin (as in Ruby) for the IDisposable interface.
Is there such thing as mixins for .NET ?

What clean up code is needed? Could you give me an example? Everyone's help file says, "put clean up code here." But no one tells you what the clean up code should look like.

My email address is Adam.Volk@Consultant.volvo.com

Here is the class I wrote that I'm trying to clean up:




Public Class truck_entry

'Public Class BaseResource
Implements IDisposable
' Pointer to an external unmanaged resource.
Private handle As IntPtr

' Track whether Dispose has been called.
Private disposed As Boolean = False

' Other managed resource this class uses.
' Private Components As Component
Private Line_Set_Str As String
Private Location_Str As String
Private Worker_1_Str As String
Private Worker_2_Str As String
Private Alert_Str As String
Private Category_Str As String
Private Model_Str As String
Private Time_Date As Date
Private Due_time_Dbl As Double
Private Comment_Str As String
Private I As Int16


' Constructor for the BaseResource Object.
Public Sub New()
' Insert appropriate constructor code here.
End Sub

' Implement IDisposable.
' Do not make this method Overridable.
' A derived class should not be able to override this method.
Public Overloads Sub Dispose() Implements IDisposable.Dispose
Dispose(True)
' Take yourself off of the finalization queue
' to prevent finalization code for this object
' from executing a second time.
GC.SuppressFinalize(Me)
End Sub

' Dispose(disposing As Boolean) executes in two distinct scenarios.
' If disposing is true, the method has been called directly
' or indirectly by a user's code. Managed and unmanaged resources
' can be disposed.
' If disposing equals false, the method has been called by the runtime
' from inside the finalizer and you should not reference other
' objects. Only unmanaged resources can be disposed.
Protected Overridable Overloads Sub Dispose(ByVal disposing As Boolean)
' Check to see if Dispose has already been called.
If Not (Me.disposed) Then
' If disposing equals true, dispose all managed
' and unmanaged resources.
If (disposing) Then
' Dispose managed resources.
'Components.Dispose()

End If
' Release unmanaged resources. If disposing is false,
' only the following code is executed.
'CloseHandle(handle)
handle = IntPtr.Zero
' Note that this is not thread safe.
' Another thread could start disposing the object
' after the managed resources are disposed,
' but before the disposed flag is set to true.
' If thread safety is necessary, it must be
' implemented by the client.
End If
Me.disposed = True
End Sub

' This Finalize method will run only if the
' Dispose method does not get called.
' By default, methods are NotOverridable.
' This prevents a derived class from overriding this method.
Protected Overrides Sub Finalize()
' Do not re-create Dispose clean-up code here.
' Calling Dispose(false) is optimal in terms of
' readability and maintainability.
Dispose(False)
End Sub

' Allow your Dispose method to be called multiple times,
' but throw an exception if the object has been disposed.
' Whenever you do something with this class,
' check to see if it has been disposed.
Public Sub DoSomething()
If Me.disposed Then
'Throw New ObjectDisposedException
MsgBox("Dispose Called Too Often")
End If
End Sub

Public Property ID() As Int16
Get
Return I
End Get
Set(ByVal Value As Int16)
I = Value
End Set
End Property

Public Property Line_Set() As String
Get
Return Line_Set_Str
End Get
Set(ByVal Value As String)
Line_Set_Str = Value
End Set
End Property

Public Property Location() As String
Get
Return Location_Str
End Get
Set(ByVal Value As String)
Location_Str = Value
End Set
End Property

Public Property Worker_1() As String
Get
Return Worker_1_Str
End Get
Set(ByVal Value As String)
Worker_1_Str = Value
End Set
End Property

Public Property Worker_2() As String
Get
Return Worker_2_Str
End Get
Set(ByVal Value As String)
Worker_2_Str = Value
End Set
End Property

Public Property Alert() As String
Get
Return Alert_Str
End Get
Set(ByVal Value As String)
Alert_Str = Value
End Set
End Property

Public Property Category() As String
Get
Return Category_Str
End Get
Set(ByVal Value As String)
Category_Str = Value
End Set
End Property

Public Property Model() As String
Get
Return Model_Str
End Get
Set(ByVal Value As String)
Model_Str = Value
End Set
End Property

Public Property Time() As Date
Get
Return Time_Date
End Get
Set(ByVal Value As Date)
Time_Date = Value
End Set
End Property

Public Property Due_time() As Double
Get
Return Due_time_Dbl
End Get
Set(ByVal Value As Double)
Due_time_Dbl = Value
End Set
End Property

Public Property Comment() As String
Get
Return Comment_Str
End Get
Set(ByVal Value As String)
Comment_Str = Value
End Set
End Property

'Public Sub dispose()
' GC.Collect()
'End Sub

Public Sub Clear()
Line_Set = ""
Model = ""
Category = ""
Location = ""
Worker_1 = ""
Worker_2 = ""
Alert = ""
Due_time = 0
'time = ##
Comment = ""
End Sub

End Class