Including custom dll and dylib in MonoMac app

bundle, dylib, mono, monomac

Solution

Have a look at my answer to this question: Setting path of the Native Library for DllImport on Mono for Mac

The binary launcher comes from monodevelop/main/build/MacOSX/monostub.m.

You can use either `MyApp.app/Contents/Frameworks` or some other path, the important part is not to use any path names in your `[DllImport]` but instead add the `<dllmap>` using `@executable_path` to your `app.config` like I explained in that other answer.

There's a also a link to a test app on github in there.

Detailed Instructions

Pick a path inside the `MyApp.app` to install your native dll, for instance `Contents/SharedSupport/sqlite3.0.8.6.dylib`.

Compute the relative path from the directory where the managed assembly is located to the native `.dll` and prepend `@executable_path` to it.

For instance, if your managed assembly is in `Contents/MonoBundle/MyApp.exe` and the native dll in `Contents/SharedSupport/sqlite3.0.8.6.dylib`, then it's `@executable_path/../SharedSupport/sqlite3.0.8.6.dylib`.

Change the installed name of the library to this relative path using `install_name_tool`.

Add a new `MyApp.exe.config` file to your project, containing

<configuration>
  <dllmap dll="sqlite" target="@executable_path/../SharedSupport/sqlite3.0.8.6.dylib" />
</configuration>

Use the path that you computed in step 2. for the `target` field. Right-click the file in MonoDevelop, select "Quick Properties" from the context menu and enable "Copy to Output directory". This will copy the file into the `Contents/MonoBundle` directory, so it sits right next to your `MyApp.exe`.

Use `[DllImport ("sqlite")]` to reference this in your code.

When another library references it

When another library, for instance `Mono.Data.Sqlite.dll` references it, it get a little bit more complicated.

Use the same steps as above, but you need to figure out which name that other library is using in its `[DllImport]` to reference the native library and put that into the `<dllimport dll="..." />`. You can either look for the `[DllImport]` statements in the source code or run `monodis` on the assembly and search for `pinvokeimpl`, for instance:

// method line 679
.method assembly static hidebysig pinvokeimpl ("sqlite3" as "sqlite3_create_function" cdecl )
       default int32 sqlite3_create_function (native int db, unsigned int8[] strName, int32 nArgs, int32 nType, native int pvUser, class Mono.Data.Sqlite.SQLiteCallback func, class Mono.Data.Sqlite.SQLiteCallback fstep, class Mono.Data.Sqlite.SQLiteFinalCallback ffinal)  cil managed preservesig 
{
    // Method begins at RVA 0x0
} // end of method UnsafeNativeMethods::sqlite3_create_function

So `Mono.Data.Sqlite.dll` is using "sqlite3" to reference the native dll, so your `MyApp.exe.config` file will look like this:

    <configuration>
      <dllmap dll="sqlite3" target="@executable_path/../SharedSupport/sqlite3.0.8.6.dylib" />
    </configuration>

Problem

Original source

Related problems

• Setting path of the Native Library for DllImport on Mono for Mac