.net - Using Class as one parameter - vb.net

Question

I have a class with several properties.
Public Class test
Public Property a As String
Public Property b As String
Public Property c As String
Public Property d As String
Public Property e As String
Public Property f As String
Public Property g As String
End Class
In my VB.net code, I am assigning a value to each property.
I want to send the whole test class as one parameter, and use all the values inside it.
So that if I add extra parameters later on, I want them to be used dynamically, instead of writing this everytime:
Textbox1.text= test.a & test.b & test.c .......
Any way to do this?
Im not really writing the values in a textbox, but this is just an simplified example.

Answer 1

I think what you want is a property. You'll need to add a property to your class like:
Public Property Combination() As String
Get
Return a & b & c & d & e ...
End Get
End Property
Then to get the value you'd use
Textbox1.text = test.combination
(for more details you can see http://www.dotnetperls.com/property-vbnet)

Answer 2

I recommend you override the built-in ToString function. Also, to further simplify this, add a CType operator.
Public Class test
Public Property a As String
Public Property b As String
Public Property c As String
Public Property d As String
Public Property e As String
Public Property f As String
Public Property g As String
Public Shared Widening Operator CType(obj As test) As String
Return If((obj Is Nothing), Nothing, obj.ToString())
End Operator
Public Overrides Function ToString() As String
Return String.Concat(Me.a, Me.b, Me.c, Me.d, Me.e, Me.f, Me.g)
End Function
End Class
The you could just do:
Textbox1.text = test

Answer 3

There is a way to dynamically get and set the value of properties on any object. Such functionality in .NET is collectively referred to as Reflection. For instance, to loop through all of the properties in an object, you could do something like this:
Public Function GetPropertyValues(o As Object) As String
Dim builder As New StringBuilder()
For Each i As PropertyInfo In o.GetType().GetProperties
Dim value As Object = Nothing
If i.CanRead Then
value = i.GetValue(o)
End If
If value IsNot Nothing Then
builder.Append(value.ToString())
End If
Next
Return builder.ToString()
End Function
In the above example, it calls i.GetValue to get the value of the property, but you can also call i.SetValue to set the value of the property. However, reflection is inefficient and, if used inappropriately, it can lead to brittle code. As such, as a general rule, you should avoid using reflection as long as there is any other better way to do the same thing. In other words, you should typically save reflection as a last resort.
Without more details, it's difficult to say for sure what other options would work well in your particular situation, but I strongly suspect that a better solution would be to use a List or Dictionary, for instance:
Dim myList As New List(Of String)()
myList.Add("first")
myList.Add("second")
myList.Add("third")
' ...
For Each i As String In myList
Textbox1.Text &= i
Next
Or:
Dim myDictionary As New Dictionary(Of String, String)()
myDictionary("a") = "first"
myDictionary("b") = "first"
myDictionary("c") = "first"
' ...
For Each i As KeyValuePair(Of String, String) In myDictionary
Textbox1.Text &= i.Value
Next