Re: Converting Structures to Classes with reflection

Nigel,
You are asking the output object for the value of the field.

> Outfields(j).SetValue(oOut,
> Infields(i).GetValue(oIn), Nothing)

You are asking the output object for a list of properties, but you only
define fields.

> Public Class TestClass
> Public Property TestStr As String
...
> Public Property TestInt As Integer
...
> Public Sub New()
> Me.TestInt = 0
> Me.TestStr = ""
> End Sub
> End Class

You are using ByRef parameters, but you don't assign a value to the
parameter itself.

> Public Function StructToClass(ByVal oIn As ValueType, ByVal oOut As
> Object) As Boolean

ByRef parameters allows a called function to modify the callers variables,
it is not used for "optimizing"! Classes are already Reference types.
Passing an object ByVal means you are passing a reference to the actual
object on the heap. Passing an object ByRef means you are passing a
reference to variable that contains a reference to the actual object on the
heap.

Try:

Public Class Converter

Public Function StructToClass(ByVal oIn As ValueType, ByVal oOut As
Object) As Boolean
Dim i As Integer
Dim Infields() As FieldInfo
Infields = oIn.GetType.GetFields

Dim j As Integer
Dim Outfields() As PropertyInfo
Outfields = oOut.GetType.GetProperties

For i = 0 To Infields.Length - 1
For j = 0 To Outfields.Length - 1
If Outfields(j).Name = Infields(i).Name Then
Outfields(j).SetValue(oOut,
Infields(i).GetValue(oIn), Nothing)
Exit For
End If
Next
Next
Return True
End Function
End Class

Public Class TestClass
Private m_testStr As String
Private m_testInt As Integer
Public Property TestStr() As String
Get
Return m_testStr
End Get
Set(ByVal value As String)
m_testStr = value
End Set
End Property
Public Property TestInt() As Integer
Get
Return m_testInt
End Get
Set(ByVal value As Integer)
m_testInt = value
End Set
End Property
Public Sub New()
Me.TestInt = 0
Me.TestStr = ""
End Sub
End Class

Public Structure TestStruct
Public TestStr As String
Public TestInt As Integer
End Structure

--
Hope this helps
Jay B. Harlow [MVP - Outlook]
..NET Application Architect, Enthusiast, & Evangelist
T.S. Bradley - http://www.tsbradley.net


"Nigel" <Nigel@discussions.microsoft.com> wrote in message
news:EBE3D843-FDA8-43FA-8921-233A28B71BB8@microsoft.com...
> Hallo Everyone,
>
> I want to transfer the contents of a structure to a class. I have tried
> the
> following but it does not work, can anyone see what I have done wronG
>
> Imports System.Reflection
> Public Class Converter
> Public Function StructToClass(ByRef oIn As ValueType, ByRef oOut As
> Object) As Boolean
> Dim i As Integer
> Dim Infields() As FieldInfo
> Infields = oIn.GetType.GetFields
>
> Dim j As Integer
> Dim Outfields() As PropertyInfo
> Outfields = oOut.GetType.GetProperties
>
> For i = 0 To Infields.Length - 1
> For j = 0 To Outfields.Length - 1
> If Outfields(j).Name = Infields(i).Name Then
> Outfields(j).SetValue(oOut,
> Infields(i).GetValue(oOut), Nothing)
> Exit For
> End If
> Next
> Next
> Return True
> End Function
>
> Public Class TestClass
> Public TestStr As String
> Public TestInt As Integer
> Public Sub New()
> Me.TestInt = 0
> Me.TestStr = ""
> End Sub
> End Class
>
> Public Structure TestStruct
> Public TestStr As String
> Public TestInt As Integer
> End Structure
>
> <TestMethod()> Public Sub TestMethod1()
> Dim iOut As New TestClass
> Dim inData As TestStruct = Nothing
> inData.TestInt = 10
> inData.TestStr = "Hallo"
> Dim iConverter As New ClassLibrary1.Converter
> iConverter.StructToClass(inData, iOut)
> Assert.IsTrue(iOut.TestInt = 10) ' <--- Failes here
> Assert.IsTrue(iOut.TestStr = "Hallo")
> End Sub