CODEWITHSUNDEEP
c#reflection.net-assembly
bevacqua
bevacqua

Reputation: 48526

Assembly.GetAssembly(type) vs type.Assembly

I wanted to know what are the benefits, if any, to calling either of these methods, and why?
Are they functionally equivalent, or should I always be choosing one over the other?

Upvotes: 4

Views: 2347

Answers (2)

Chris Sinclair
Chris Sinclair

Reputation: 23218

AFAIK they're functionally equivalent, however Assembly.GetAssembly(Type) is not available in the core-clr (Silverlight and the like)

You would get different errors based on whether or not your Type is null. Type.Assembly will throw a NullReferenceException (naturally) whereas Assembly.GetAssembly(Type) would throw an ArgumentNullException. Based on your code you might prefer one or the other.

EDIT: Looking at the source, for Assembly.GetAssembly:

public static Assembly GetAssembly(Type type)
{
    if (type == null)
        throw new ArgumentNullException("type");
    Contract.EndContractBlock();

    Module m = type.Module;
    if (m == null)
        return null;
    else
        return m.Assembly;
}

Whereas System.Type.Assembly:

public abstract Assembly Assembly {
    get;
}

If I recall correctly, the System.Type for runtime types are their own subclasses (or something like that) So I guess each one maybe overrides and simply directly returns an assembly reference. Beyond that, I don't think there's any significant difference for you to worry about with your code beyond null handling which is up to you. (Or if you're running the Core-CLR in which case you don't have Assembly.GetAssembly anyway so you must use Type.Assembly)

Upvotes: 4

Robert Harvey
Robert Harvey

Reputation: 180878

From the documentation for Type.Assembly

If the current Type object represents a constructed generic type, this property returns the assembly that contains the generic type definition.

For example, suppose you create an assembly named MyGenerics.dll that contains the generic type definition MyGenericStack<T>. If you create an instance of MyGenericStack<int> in another assembly, the Assembly property for the constructed type returns an Assembly object that represents MyGenerics.dll

From the documentation for Assembly.GetAssembly:

In order to call this method, you must have a Type object, which means that the assembly in which the class is defined must already be loaded.

Upvotes: 0

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