How to control which assembly .Net chooses in a namespace conflict?

Question

I need to (bear with me) for some reason or another use the WinRT version of the System.Text.Encoding namespace. I can add a reference to the assembly manually and such, but it will still use mscorlib's implementation. And I can't completely remove mscorlib apparently.

How can I force my project to use WinRT's System.Text.Encoding.dll instead of mscorlib?

Basically, I need it to generate this piece of IL:

call class [System.Text.Encoding]System.Text.Encoding [System.Text.Encoding]System.Text.Encoding::get_UTF8()

instead of this:

call class [mscorlib]System.Text.Encoding [mscorlib]System.Text.Encoding::get_UTF8()

Is an app permitted in the Windows Store that references both assemblies like this? — Jeff Yates, Sep 20 '12 at 15:52
Just curious, thanks. See my answer for details on how to resolve this for you. — Jeff Yates, Sep 20 '12 at 16:10
Wouldn't a class library targeted at WinRT use the version you want? (I'm not sure you can target it like that, but there is that choice when creating portable library.) — svick, Sep 20 '12 at 16:20

score 9 · Accepted Answer · edited May 23 '17 at 10:30

You need to alias the reference. To do this, go to Solution Explorer and select the reference you want to alias. View the Properties and edit the Aliases field to add a unique alias name.

Alias field in properties with custom alias, myalias

Once you've defined a unique alias, you edit your code to add the extern alias declaration.

extern alias myalias;

Finally, you reference the types via the alias as in (this example aliased System.dll):

myalias::System.Diagnostics.Trace.WriteLine("I referenced this via my alias.");

This now targets the exact reference you want, even if other references also provide a type with the same name and namespace.

For additional info on aliases, see this StackOverflow answer on What use is the Aliases property of assembly references.

This ended up not being the solution to my actual problem, but it does perfectly answer the question (though it's probably a duplicate) — Earlz, Sep 20 '12 at 18:37

How to control which assembly .Net chooses in a namespace conflict?

1 Answers1

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