How can I call explicitly implemented interface method from PowerShell?

Question

Code:

add-type @"
    public interface IFoo
    {
        void Foo();
    }

    public class Bar : IFoo
    {
        void IFoo.Foo()
        {
        }
    }
"@ -Language Csharp

$bar = New-Object Bar
($bar -as [IFoo]).Foo() # ERROR.

Error:

Method invocation failed because [Bar] doesn't contain a method named 'Foo'.

score 6 · Answer 1 · answered Oct 08 '13 at 14:36

You can do something like

$bar = New-Object Bar
[IFoo].GetMethod("Foo").Invoke($bar, @())

You get (the reflection representaion of) the member of IFoo from the Type object and call an Invoke overload. Too bad one has to do it that way, though. Similar approach for explicitly implemented properties etc.

If the method takes arguments, they go in the array @() after the comma in the code above, of course.

score 5 · Answer 2 · edited Sep 27 '19 at 22:42

5

I wrote something for PowerShell v2.0 that makes it easy to call explicit interfaces in a natural fashion:

PS> $foo = get-interface $bar ([ifoo])
PS> $foo.Foo()

See:

http://www.nivot.org/2009/03/28/PowerShell20CTP3ModulesInPracticeClosures.aspx (archived here).

It does this by generating a dynamic module that thunks calls to the interface. The solution is in pure powershell script (no nasty add-type tricks).

-Oisin

edited Sep 27 '19 at 22:42

dbc

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answered Apr 17 '09 at 17:17

x0n

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Thank you, Oisin! I added an answer based on your solution here http://stackoverflow.com/questions/745956/how-can-i-dispose-system-xml-xmlwriter-in-powershell/767661#767661 – alex2k8 Apr 20 '09 at 10:16

score 2 · Accepted Answer · answered Apr 14 '09 at 02:29

2

Bad news: It's a bug.

https://connect.microsoft.com/feedback/ViewFeedback.aspx?FeedbackID=249840&SiteID=99

answered Apr 14 '09 at 02:29

Kredns

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1

I have Microsoft Live account, but still can't open the link: Page Not Found. :-( – alex2k8 Apr 14 '09 at 02:43
1

More info: http://www.vistax64.com/powershell/169391-access-interfaces-members-net-object.html – JasonMArcher Apr 16 '09 at 01:41

How can I call explicitly implemented interface method from PowerShell?

3 Answers3

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