C#•4mo ago

Variable type passed to generic

Is there any way to get around this being an error?

c#
Type type = Type.GetType("OSIsoft.PI.Net, PIThreadInfo");

return powershell.Invoke<type>()

c#
Type type = Type.GetType("OSIsoft.PI.Net, PIThreadInfo");

return powershell.Invoke<type>()

19 Replies

Buddy•4mo ago

what gives an error and can you screenshot it?

engineertdog•4mo ago

You can't use a variable as a type

Jimmacle•4mo ago

yes, use reflection to get the correct generic instantiation of the method

engineertdog•4mo ago

I don't need a method from the type

Jimmacle•4mo ago

you need the correct generic method, which you can't get with a variable using that syntax

engineertdog•4mo ago

I need to invoke the powershell method with a type that I will only be able to know by name

Jimmacle•4mo ago

yes, i know what you're trying to do you can't do it without more reflection you need to get the method info for the open generic powershell.Invoke method then make the generic method using the type variable so you can call it something roughly like

        var method = powershell.GetType().GetMethod("Invoke").MakeGenericMethod(type);
        method.Invoke(powershell);

        var method = powershell.GetType().GetMethod("Invoke").MakeGenericMethod(type);
        method.Invoke(powershell);

engineertdog•4mo ago

Okay, so that is similar to what I had seen, it just looked like it wasn't what I needed

c#
Type type = Type.GetType("OSIsoft.PI.Net.PIThreadInfo");
var fooMethod = powershell.GetType().GetMethod("Invoke").MakeGenericMethod(new[] { type });

return (fooMethod.Invoke(null, null) as Collection<PSObject>).Select(psobject => psobject.BaseObject).ToList();

c#
Type type = Type.GetType("OSIsoft.PI.Net.PIThreadInfo");
var fooMethod = powershell.GetType().GetMethod("Invoke").MakeGenericMethod(new[] { type });

return (fooMethod.Invoke(null, null) as Collection<PSObject>).Select(psobject => psobject.BaseObject).ToList();

[Error: Ambiguous match found.] { name: 'System.Reflection.AmbiguousMatchException' } Close, but should be able to get there

Jimmacle•4mo ago

you'll have to provide enough information to GetMethod to make it not ambiguous i don't know what type powershell is but i'd guess there are multiple overloads of Invoke

engineertdog•4mo ago

Yeah, there's 8 I call it with no params powershell.Invoke(); But calling fooMethod.Invoke() with no params throws an error

Jimmacle•4mo ago

you have to pass it the powershell instance since it's not a static method

engineertdog•4mo ago

fooMethod.Invoke(powershell, new object[] { })

Jimmacle•4mo ago

not sure you need to pass it an empty array, i haven't had to do reflection like this in a bit .GetMethod("Invoke", BindingFlags.Public | BindingFlags.Instance, []); should find the parameterless overload you want if you didn't get that yet

engineertdog•4mo ago

I tried null too Ah sorry, this was Framework

Jimmacle•4mo ago

ah, substitute [] for an empty array then no cool syntax allowed in framework

engineertdog•4mo ago

Yeah, I hate this vendor

engineertdog•4mo ago

Jimmacle•4mo ago

maybe the api is different :PepeHmmm: ultimately you want to give it the empty type array, so whatever overload lets you do that with the least amount of extra stuff

Waffles from Human Resources•4mo ago

:SCtwocats:

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Variable type passed to generic