How to serialize only properties which passed to constructor?

Question

I have classes which I serialize to a JSON String. For that, I'm using Newtonsoft.Json

It looks like this:

<JsonObject()>
Public Class MyClass

    Private _a;
    Private _b;

    Public Sub New(ByVal an As String, ByVal b as String)
        _a = a
        _b = b
    End Sub

    Public Property a As String
        Get
            Return _a
         End Get
         Protected Set(value As String)
             _a = value
         End Set
    End Property

    Public Property b As String
        Get
            Return _b
        End Get
        Protected Set(value As String)
            _b = value
        End Set
    End Property

End Class

I put them in a list and serialize this:

JsonConvert.SerializeObject(listMyObject)

But sometimes I don't need every Property in my JSON String. Is it possible to serialize properties I passed to the constructor? As in this case?:

Public Sub New(ByVal an As String)
    _a = a
End Sub

@ThePerplexedOne - please note that any user is able to edit posts, including tags. Any user with 2000 or higher rep will have edits applied immediately. — theMayer, Feb 06 '20 at 16:23
I guess you want to have multiple constructor overloads, and depending on which was used when creating the object, you would only want to serialize specific properties, is this correct? — djv, Feb 06 '20 at 16:56

score 3 · Answer 1 · answered Feb 06 '20 at 16:20

3

You can use the attribute <JsonIgnore> over the properties you don't want to serialize

answered Feb 06 '20 at 16:20

Stefano Cavion

641
8
16

djv · Accepted Answer · 2020-02-06T20:59:06.203

Check out Newtonsoft json Serialize Conditional Property.

This answer in C# demonstrates it in action.

In your case,

<JsonObject()>
Public Class MyClassName

    Public Property A As String
    Private ReadOnly _shouldSerializeA As Boolean
    Public Function ShouldSerializeA() As Boolean
        Return _shouldSerializeA
    End Function

    Public Property B As String
    Private ReadOnly _shouldSerializeB As Boolean
    Public Function ShouldSerializeB() As Boolean
        Return _shouldSerializeB
    End Function

    Public Sub New(ByVal a As String, ByVal b As String)
        Me.A = a
        Me.B = b
        Me._shouldSerializeA = True
        Me._shouldSerializeB = True
    End Sub

    Public Sub New(ByVal a As String)
        Me.A = a
        Me._shouldSerializeA = True
        Me._shouldSerializeB = False
    End Sub

End Class

How to serialize only properties which passed to constructor?

2 Answers2