FSharp.Data 'System.MissingMethodException' when calling Freebase Provider from C#

问题

Hi I have this piece of code on F#, if I test it from the F# Interactive Editor both isPalindrome and Extract methods work well:

namespace Portable3
open FSharp
open FSharp.Data
open Microsoft.FSharp.Linq 
open FSharp.Data.FreebaseOperators
open MyTrip.Model.MyTrip
open MyTrip.Model.FreeBase
open System.Runtime
open System.Linq

module math = 
let isPalindrome (str : string) = 
 let rec check(s : int, e : int) =
    if s = e then true
    elif str.[s] <> str.[e] then false
    else check(s + 1, e - 1)
 check(0, str.Length - 1)

 [<AutoOpen>]
 module Extractor =

[<Literal>] 
let FreebaseApiKey = "AIzaSyCO31Ls"
type FreebaseDataWithKey = FreebaseDataProvider<Key=FreebaseApiKey>

let Extract mid = let dataWithKey = FreebaseDataWithKey.GetDataContext()
                  let place = dataWithKey.Commons.Travel.``Travel destinations``.Where( fun x-> x.MachineId = mid) |> Seq.toList                           
                  let result = new Place()   
                  let firstPlace = place.Head
                  result.Name <- firstPlace.Name                      
                  result

And I call this code from a C# Console app like this:

 class Program
{
    static void Main(string[] args)
    {
        //Works well
        var isPalin = math.isPalindrome("ABsBA");
        //fails
        var res = Extractor.Extract("/m/04jpl");
        Console.WriteLine(res);
        Console.Read();

    }
}

The console C# project is .net Framework 4.5.1 version, I downloaded the FSharp.Data and FSharp.Core on this project also. When executing isPalindrome works well but when I'm about to execute the Extract method this error appears:

An unhandled exception of type 'System.MissingMethodException' occurred in FsharpConsoleTest.exe

Additional information: Method not found: 'FSharp.Data.Runtime.Freebase.FreebaseDataContext   FSharp.Data.Runtime.Freebase.FreebaseDataContext._Create(System.String, System.String, System.Boolean, System.String, System.Boolean, System.Boolean)'.

Any idea on what's happening? I searched on internet but didn't found anything relevant. Thanks!

回答1:

The problem at the end was using a portable library with FSharp.Data. I tried using it in a normal F# library and I found no problems, I had all the debuggin capabilities, and no errors from c# integration with f# are happening!

来源：https://stackoverflow.com/questions/22608519/fsharp-data-system-missingmethodexception-when-calling-freebase-provider-from

标签

freebase

f#-data

missingmethodexception