Using for each to iterate class properties - vb.net

Question

I have this class
Public Class TExperience
Public ID As Integer
Public CompanyName As String
Public Country As String
Public Years As Integer
Public Months As Integer
Public JobTitle As String
Public Function Arr() As String()
Return {"ID", "CompanyName", "Country", "Years", "Months", "JobTitle"}
End Function
End Class
and this is how it work
Public Function Set()
Dim D As New TExperience
D.CompanyName = "Any Data"
D.Country = "Any Data"
D.ID = "Any Data"
D.JobTitle = "Any Data"
D.Months = "Any Data"
End Function
I need to exchange this by "For Each....." in class
D.CompanyName = "Any Data"
D.Country = "Any Data"
D.ID = "Any Data"
D.JobTitle = "Any Data"
D.Months = "Any Data"
How to do this?

Answer 1

Yea, this is possible if...
Note: you posted class with public fields, e.g. Public CompanyName As String. While it is usually good idea to use properties - Public Property CompanyName As String. The code below is for class properties but you can substitute PropertyInfo for FieldInfo. However, it is recommended to use properties to expose class values.
If you're looking for yes/no answer to question, can setting properties via for-each happen?, the answer is yes. But more questions about your question should arise. When, why, what for..., etc.
For example, we have a situation that specific types have common properties with other types, sometimes even deriving from those types and we need to convert them. One way was to use a "Decorator" pattern. But here is what we've done to hydrate properties (disclaimer - code was converted from c# via converter and I added some tings like "as type", I am not sure it is 100% correct)
''' Everything "S" - source, "D" - destination. "T" - type
Public Shared Function Hydrate(Of TS, TD)(source As TS, destination As TD) As TD
Dim sPI() As PropertyInfo =
source.[GetType]().GetProperties(BindingFlags.[Public] Or BindingFlags.Instance)
Dim dPI() As PropertyInfo =
destination.[GetType]().GetProperties(BindingFlags.[Public] Or BindingFlags.Instance)
For Each s As PropertyInfo In sPI
Dim d As PropertyInfo =
dPI.FirstOrDefault(Function(pi) pi.Name = s.Name AndAlso pi.PropertyType = s.PropertyType)
If d IsNot Nothing Then
d.SetValue(destination, s.GetValue(source, Nothing), Nothing)
End If
Next
Return destination
End Function
So, here we go. In this example properties iterated and when their names and data types match exactly, they are populated. But other than hydration of similar models, what is the use of it? I mean, this is what happens internally when JSON being deserialized, etc. But in everyday programming you don't do anything like this.

Answer 2

What you're asking for is not possible. As you have been told, For Each is for performing the same action for each item in an enumerable list. The properties of an object are not an enumerable list, therefore For Each is not applicable in this case. The way to set multiple property values is just as you are doing now.
That said, when setting multiple properties on a just-created object, you can use object initialiser syntax, e.g.
Dim D As New TExperience With
{
.CompanyName = "Any Data",
.Country = "Any Data",
.ID = "Any Data",
.JobTitle = "Any Data",
.Months = "Any Data"
}
Obviously not what you were asking for but still an improvement on what you're doing now. Alternatively, if the object requires all that data, it is preferable to declare a constructor with appropriate parameters, that way, the call MUST provide the data. You've still got to set each property individually inside the constructor though.