How to serialize an object with newtonsoft, which has a value with backslash [\] - vb.net

Question

I prepared this small example to show you my problem (vb.net and Newtonsoft)
I would prefer that the solution be done with Newtonsoft.
Public Class Message
Property Emoji As String
End Class
Public Sub GetJson()
Dim msgObject As New Message With {.Emoji = "\uD83D\uDE00"}
'Option 1
Dim JsonSerializerSettings As New JsonSerializerSettings
JsonSerializerSettings.StringEscapeHandling = StringEscapeHandling.EscapeNonAscii
Dim msgJson_1 As String = Newtonsoft.Json.JsonConvert.SerializeObject(msgObject, JsonSerializerSettings)
'Option 2
Dim msgJson_2 As String = Newtonsoft.Json.JsonConvert.SerializeObject(msgObject, Newtonsoft.Json.Formatting.None)
'Option 3
Dim stringWriter As New StringWriter()
Using writer As New JsonTextWriter(stringWriter)
writer.Formatting = Formatting.None
Dim serializer As New JsonSerializer()
serializer.Serialize(writer, msgObject)
End Using
Dim msgJson_3 As String = stringWriter.ToString()
End Sub
with none of the three options works, it always results in
{
"Emoji": "\\uD83D\\uDE00"
}
The result I need is
{
"Emoji": "\uD83D\uDE00"
}
How do I set Newtonsoft to not take into account the backslash character, as an escaped character?
Another unorthodox way could be:
jsonString = jsonString.replace("\\","\")
I do not really like
Thanks!!!!

Answer 1

\ is an escape char in JSON hence if you try and serialise a \ it gets escaped as \\ then when you deserialise \\ you get \
My guess is you have been given an example asking you to send "Emoji": "\uD83D\uDE00"
In json (and C#) \u#### specifies a unicode character (usually for something not found on a keyboard) as you are using VB.NET instead you should use $"{ChrW(&HD83D)}{ChrW(&HDE00)}"

Answer 2

"jsonString = jsonString.replace("//","/") " will never work, this is more safe way
json = json.Replace("\\\\u","\\u");
or since you don't like old, good classical solutions
json = Regex.Replace(json, #"\\u", #"u");
//or
json = json.Replace(#"\\u", #"\u");
even this will work in your case ( but I will not recommend for another cases since it is not safe)
json = Regex.Unescape(json);