使用方括号 VB.NET 反序列化 JSON

Question

so I have the following json string:

{
    "domain": "something.com",
    "subject": {
        "id": "1111",
        "name": "My name",
        "date": "2016-07-06"
    },
    "atributes": [
        {
            "height": "178",
            "age": "45"
        }
    ]
}

I can parse the first "round bracket" without a problem by doing this:

    Dim json = Await client.GetStringAsync(url) //gettin the json from an API
    Dim jss = Newtonsoft.Json.JsonConvert.DeserializeObject(Of Object)(json) 

    For Each Jproperty In jss("subject")

        Dim name1 = Jproperty.Name.ToString
        Dim value1 = Jproperty.Value.ToString

        TextBox1.Text &= name1 & ": " & value 1
        //Which returns: 
        //id: 111
        //name: My name
        //date: 2016-07-06

    Next

Cool, so far so good, but I can't for the life of me doing the same with "atributes", maybe because it's inside some square brackets which make it an array I believe? When I try to do the same in ANOTHER for each I got an exception that says that "Name" cannot be found in the 'JObject' object. Using Dim height = Jproperty.Name.ToString

BUT when I call "atributes" using something like

Dim height = Jproperty.ToString (without "Name") it works but returns a giant string and that's not really what I need.

Thanks and I hope I made sense!

Answer 1

If the JSON you're expecting from your API call is always of the same structure, I'd recommend creating a class and deserializing to that instead of Object . (The content in square brackets will be represented by a collection type in your class.)

Eg

Class JsonClass
    <JsonProperty("domain")>
    Property [Domain] As String
    <JsonProperty("subject")>
    Property [Subject] As cSubject
    <JsonProperty("atributes")>
    Property [Attibutes] As List(Of cAttribute)

    Class cSubject
        <JsonProperty("id")>
        Property [Id] As String
        <JsonProperty("name")>
        Property [Name] As String
        <JsonProperty("date")>
        Property [Date] As String
    End Class

    Class cAttribute
        <JsonProperty("height")>
        Property [Height] As String
        <JsonProperty("age")>
        Property [Age] As String
    End Class
End Class

Dim jss As JsonClass = Newtonsoft.Json.JsonConvert.DeserializeObject(Of JsonClass)(json) 

There is no need for any looping through raw JSON using this approach.

Answer 2

You are right, "square brackets" represents an Array of objects.
Notice array of objects , this mean you need another "third" foreach to loop through properties of the object.

Dim json = Await client.GetStringAsync(url)
Dim jss = Newtonsoft.Json.JsonConvert.DeserializeObject(Of Object)(json) 

For Each property In jss("subject")
    Dim name1 = property.Name.ToString()
    Dim value1 = property.Value.ToString()

    ' ...
Next

For Each attribute In jss("attributes")
    For Each property In attribute
        Dim name1 = property.Name.ToString()
        Dim value1 = property.Value.ToString()

        ' ...
    Next
Next