Excel-DNA: F# Error Initialization [Error] Method not registered

问题

As a neophyte F# developer, I am trying to create a simple Excel-DNA function as follows:

[<ExcelFunction(Name="ACount", Description="Count items", Category="Misc Functions", IsThreadSafe = true)>]
let aCount (range: _[]) (filter: string) = 
    let result = 
        Seq.ofArray range
        |> Seq.filter (fun x -> x = filter)
        |> Seq.length
    result

but it generates the following error on loading to Excel 2016 (64-bit):

Initialization [Error] Method not registered - unsupported signature, abstract or generic:

What am I doing wrong?

回答1:

Thanks Govert.

The following works but is it sufficiently idiomatic?

[<ExcelFunction(Name="ACount", Description="Count items", Category="Misc Functions", IsThreadSafe = true)>]
let aCount (range: obj[]) (filter: string) = 
    let result = 
        Seq.ofArray range
        |> Seq.filter (fun x -> string x = filter)
        |> Seq.length
    result

Any constructive changes welcome!

来源：https://stackoverflow.com/questions/46407760/excel-dna-f-error-initialization-error-method-not-registered