CODEWITHSUNDEEP
c#.netreflectionassemblies
sharptooth
sharptooth

Reputation: 170489

Can I rely on specific capitalization of .NET assembly names?

In my code, I want to check if a specific assembly is loaded. I have this code:

var assembly = AppDomain.CurrentDomain
    .GetAssemblies()
    .Where(a => a.FullName.StartsWith("Microsoft.WindowsAzure.ServiceRuntime"))
    .SingleOrDefault();

Now, this code relies on specific capitalization of the assembly – the comparison is case-sensitive.

Do I need the comparison to be case-insensitive or can I expect the specific capitalization at all times?

Upvotes: 1

Views: 596

Answers (2)

Palec
Palec

Reputation: 13551

The docs acknowledge inconsistencies in the case sensitivity of assembly names and they recommend comparing them case-sensitively:

The runtime treats assembly names as case-insensitive when binding to an assembly, but preserves whatever case is used in an assembly name. Several tools in the Windows SDK handle assembly names as case-sensitive. For best results, manage assembly names as though they were case-sensitive. -- https://learn.microsoft.com/dotnet/standard/assembly/names

Yet, if you choose to compare the name of the assembly (essentially AssemblyName.Name) case-insensitively, it is not clear whether to compare ordinally or using the invariant culture. I would prefer ordinal comparison in such technical contexts, i.e. StringComparer.OrdinalIgnoreCase and StringComparison.OrdinalIgnoreCase. As the best practices for comparing strings advise:

Use the non-linguistic StringComparison.Ordinal or StringComparison.OrdinalIgnoreCase values instead of string operations based on CultureInfo.InvariantCulture when the comparison is linguistically irrelevant (symbolic, for example).

Upvotes: 0

Andre Loker
Andre Loker

Reputation: 8408

According to this, the runtime treats assembly names as case-insenstive. That is, you won't have two assemblies loaded at the same time with names that only differ in their capitalization.

So, if you ONLY want to check for a specific assembly name you should do a case-insensitive comparison using this overload of StartsWith with StringComparison .InvariantCultureIgnoreCase to avoid the (very rare) case where the capitalization of an assembly name has changed.

a.FullName.StartsWith("Microsoft.WindowsAzure.ServiceRuntime",
     StringComparison.InvariantCultureIgnoreCase)

Upvotes: 3

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