CODEWITHSUNDEEP
c#.net.net-2.0
cjk
cjk

Reputation: 46425

How do you specify to pass a Type that is of a specific interface?

I have a method where I want to have a parameter that is a Type, but of a certain interface.

E.g.:

public static ConvertFile(Type fileType)

where I can specify fileType inherits IFileConvert.

Is this possible?

Upvotes: 2

Views: 148

Answers (5)

JaredPar
JaredPar

Reputation: 754763

Expanding on Marc's answer. He is correct, without generics there is no way to enforce this at compile time. If you can't or don't want to use generics, you can add a runtime check as follows.

public static void ConvertFile(Type type) {
  if ( !typeof(IFileType).IsAssignableFrom(type)) {
    throw new ArgumentException("type");
  }
  ...
}

Upvotes: 0

Anton Gogolev
Anton Gogolev

Reputation: 115751

If you want to enforce that at compile-time, generics are the only way:

public static ConvertFile<T>(T fileType)
    where T : IFileType

To check at run-time, you can do:

Debug.Assert(typeof(IFileType).IsAssignableFrom(fileType));

Upvotes: 1

Marc Gravell
Marc Gravell

Reputation: 1062865

One option is generics:

public static ConvertFile<T>() where T : IFileConvert
{
     Type type = typeof(T); // if you need it
}

and call as:

ConvertFile<SomeFileType>();

Upvotes: 4

Mehrdad Afshari
Mehrdad Afshari

Reputation: 422006

Nope, it's not possible. However you could do:

public static void ConvertFile<T>() where T : IFileConvert {
   Type fileType = typeof(T);
}

instead.

Upvotes: 3

Damien
Damien

Reputation: 14057

Can't you just do:

public static ConvertFile(IFileConvert fileType)

Upvotes: 0

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