How to: Reference a strong-named assembly

The process for referencing types or resources in a strong-named assembly is usually transparent. You can make the reference either at compile time (early binding) or at run time.

A compile-time reference occurs when you indicate to the compiler that the assembly to be compiled explicitly references another assembly. When you use compile-time referencing, the compiler automatically gets the public key of the targeted strong-named assembly and places it in the assembly reference of the assembly being compiled.

Note

A strong-named assembly can only use types from other strong-named assemblies. Otherwise, the security of the strong-named assembly would be compromised.

Make a compile-time reference to a strong-named assembly

At a command prompt, type the following command:

<compiler command> /reference:<assembly name>

In this command, compiler command is the compiler command for the language you are using, and assembly name is the name of the strong-named assembly being referenced. You can also use other compiler options, such as the /t:library option for creating a library assembly.

The following example creates an assembly called myAssembly.dll that references a strong-named assembly called myLibAssembly.dll from a code module called myAssembly.cs.

csc /t:library myAssembly.cs /reference:myLibAssembly.dll  

Make a run-time reference to a strong-named assembly

When you make a run-time reference to a strong-named assembly, for example by using the Assembly.Load or Assembly.GetType method, you must use the display name of the referenced strong-named assembly. The syntax of a display name is as follows:

<assembly name>, <version number>, <culture>, <public key token>

For example:

myDll, Version=1.1.0.0, Culture=en, PublicKeyToken=03689116d3a4ae33   

In this example, PublicKeyToken is the hexadecimal form of the public key token. If there is no culture value, use Culture=neutral.

The following code example shows how to use this information with the Assembly.Load method.

Assembly^ myDll =
    Assembly::Load("myDll, Version=1.0.0.1, Culture=neutral, PublicKeyToken=9b35aa32c18d4fb1");
Assembly myDll =
    Assembly.Load("myDll, Version=1.0.0.1, Culture=neutral, PublicKeyToken=9b35aa32c18d4fb1");
Dim myDll As Assembly = _
    Assembly.Load("myDll, Version=1.0.0.1, Culture=neutral, PublicKeyToken=9b35aa32c18d4fb1")

You can print the hexadecimal format of the public key and public key token for a specific assembly by using the following Strong Name (Sn.exe) command:

sn -Tp < assembly >

If you have a public key file, you can use the following command instead (note the difference in case on the command-line option):

sn -tp < public key file >

See also