F＃JsonValue AsArray在哪里？

Question

I have:

open FSharp.Data
open FSharp.Data.JsonExtensions

[<EntryPoint>]
let testjson argv =

    let json = """
    {
        "KeyValuePairs": "[{\"Key\" : \"one\", \"Value\" : \"1\"},{\"Key\" : \"two\", \"Value\" : \"2\"}]"
    }
    """

    let info = JsonValue.Parse(json)
    let infoarray = info.AsArray()

But I'm getting an error on the last line:

Error 52 The field, constructor or member 'AsArray' is not defined

even though I'm following the example here:

F# Data: JSON Parser

in the section, "Using JSON extensions". So, clearly I've got this wrong.But where?

Answer 1

You're trying to treat the JsonValue itself as an array - it's not, it's an object. It seems you probably want to treat the KeyValuePairs property as an array. So try this:

let keyValuePairs = info?KeyValuePairs.AsArray()

Answer 2

This an old question but I will leave a reply for those in need.

The mistake was when KeyValuePairs is seen as an Array but instead is a String

let json = """ {"KeyValuePairs": "[{\"Key\" : \"one\", \"Value\" : \"1\"},{\"Key\" : \"two\", \"Value\" : \"2\"}]"} """

let info = JsonValue.Parse(json)

let infoarray = info?KeyValuePairs.AsString()

let newinfo = JsonValue.Parse infoarray

printfn "%A" (newinfo.[0]?Key.AsString()) // prints "one"

Hope this was helpful!

Cheers