DefaultValue problem

[schneider]

Hello,

Have an issue with a property using the DefaultValue(Tr ue) attribute.

Imports System.Componen tModel

Public Class Class1

Private m_testValue As Boolean

<DefaultValue(T rue)> _
Public Property test() As Boolean
Get
Return m_testValue
End Get
Set(ByVal value As Boolean)
m_testValue = value
End Set
End Property

End Class

here's the steps to reproduce the problem:

1. User UI sets the Class1.test=fal se during runtime.
2. I serialize Class1 to xml and the false value is saved.
3. User UI sets the Class1.test=tru e during runtime.
4. I serialize Class1 to xml and the True value is NOT saved and the
False value is still there.


Step 4 is the problem, the file does not seem to reflect the current
state of the class.

If I remove the attribute it works fine, but the idea is the reduce the
file size and also know what the default is.

Anyone know what I'm doing wrong or missing?

Thanks,

Schneider

[Herfried K. Wagner [MVP]]

Re: DefaultValue problem

"schneider" <abd@123.com> schrieb:[color=blue]
> Have an issue with a property using the DefaultValue(Tr ue) attribute.
> [...]
> here's the steps to reproduce the problem:
>
> 1. User UI sets the Class1.test=fal se during runtime.
> 2. I serialize Class1 to xml and the false value is saved.
> 3. User UI sets the Class1.test=tru e during runtime.
> 4. I serialize Class1 to xml and the True value is NOT saved and the False
> value is still there.
>
> Step 4 is the problem, the file does not seem to reflect the current state
> of the class.[/color]

\\\
Imports System.Componen tModel
..
..
..
< _
DesignerSeriali zationVisibilit y(DesignerSeria lizationVisibil ity.Visible),
_
DefaultValue(Tr ue) _[color=blue]
> _[/color]
Public Property...
///

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[schneider]

Re: DefaultValue problem

Herfried K. Wagner [MVP] wrote:[color=blue]
> "schneider" <abd@123.com> schrieb:
>[color=green]
>> Have an issue with a property using the DefaultValue(Tr ue) attribute.
>> [...]
>> here's the steps to reproduce the problem:
>>
>> 1. User UI sets the Class1.test=fal se during runtime.
>> 2. I serialize Class1 to xml and the false value is saved.
>> 3. User UI sets the Class1.test=tru e during runtime.
>> 4. I serialize Class1 to xml and the True value is NOT saved and the
>> False value is still there.
>>
>> Step 4 is the problem, the file does not seem to reflect the current
>> state of the class.[/color]
>
>
> \\\
> Imports System.Componen tModel
> .
> .
> .
> < _
>
> DesignerSeriali zationVisibilit y(DesignerSeria lizationVisibil ity.Visible), _
> DefaultValue(Tr ue) _
>[color=green]
>> _[/color]
>
> Public Property...
> ///
>[/color]

Does not seem to work, I include a more detailed sample (must be missing
something):

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load

Dim c As New Class1
c.test = False
Class1.Serializ eObjectToFile(" C:\test.txt", c)
c.test = True
Class1.Serializ eObjectToFile(" C:\test.txt", c)


Dim b As Class1
b = DirectCast(Clas s1.DeserializeO bjectFromFile(" C:\test.txt"), Class1)

Dim a As Integer
a = 1

End Sub

Imports System.Componen tModel
Imports System.IO

Public Class Class1

Private m_testValue As Boolean

<DefaultValue(T rue),
DesignerSeriali zationVisibilit y(DesignerSeria lizationVisibil ity.Visible)> _
Public Property test() As Boolean
Get
Return m_testValue
End Get
Set(ByVal value As Boolean)
m_testValue = value
End Set
End Property

Public Shared Sub SerializeObject ToFile(ByVal fileName As String, ByVal
value As Object)

Dim writer As New StreamWriter(fi leName)

Try
' Create a new XmlSerializer instance.
Dim s As New Xml.Serializati on.XmlSerialize r(value.GetType )

' Serialize the object, and close the StreamWriter.
s.Serialize(wri ter, value)

Catch
Throw
Finally
writer.Close()
End Try
End Sub

Public Shared Function DeserializeObje ctFromFile(ByVa l fileName As
String) As Object

Dim fs As New IO.FileStream(f ileName, FileMode.Open)

Try
Dim w As New Xml.Serializati on.XmlSerialize r(GetType(Class 1))
Dim g As Object = w.Deserialize(f s)

Return g

Catch
Throw
Finally
fs.Close()
End Try
End Function

End Class

[Dustin Brisebois via DotNetMonster.com]

Re: DefaultValue problem

Private m_testvalue as Boolean = True

Property TestValue() as Boolean
Get
return m_testvalue
End Get
Set(Value as Boolean)
m_testvalue = value
End Set

right?

Everytime the Class is redeclared m_testvalue is True by Default?

--
Message posted via http://www.dotnetmonster.com

[schneider]

Re: DefaultValue problem

Dustin Brisebois via DotNetMonster.c om wrote:[color=blue]
> Private m_testvalue as Boolean = True
>
> Property TestValue() as Boolean
> Get
> return m_testvalue
> End Get
> Set(Value as Boolean)
> m_testvalue = value
> End Set
>
> right?
>
> Everytime the Class is redeclared m_testvalue is True by Default?
>[/color]

Thanks,

That was it.
Not initializing to Private m_testvalue as Boolean = True . Funny thing
is I do on others..

figures, something easy...

Schneider

[Herfried K. Wagner [MVP]]

Re: DefaultValue problem

"schneider" <eschneider100@ wi.rr.com> schrieb:[color=blue][color=green]
>> Everytime the Class is redeclared m_testvalue is True by Default?[/color]
>
> That was it.
> Not initializing to Private m_testvalue as Boolean = True . Funny thing is
> I do on others..[/color]

Well, 'DefaultValueAt tribute' doesn't set the property's value. MSDN:

| You can create a 'DefaultValueAt tribute' with any value. A member's
| default value is typically its initial value. A visual designer can use
the
| default value to reset the member's value. Code generators can use
| the default values also to determine whether code should be generated
| for the member.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>