Question about Assembly.CreateInstance()

9 Feb 2007 3:30 AM

Brad Figler

Here is my setup:

I want a plugin interface for my application.

I have my main app named App.exe
I have a plugin interface assembly named PluginInterface.dll (defines
IPluginInterface)
I have a plugin implementation named PluginTest.dll (defines TestClass)

In my application I simply do the following:

Assembly myAssembly = Assembly.LoadFile( "PluginTest.dll" );
IPluginInterface plugin = (IPluginInterface)myAssembly.CreateInstance(
"TestClass" );

plugin.Test() (one of the methods specified in the plugin interface).

I compile the code and I get the following:

MyApp.exe
PluginInterface.dll
PluginTest.dll

If I delete PluginInterface, My code won't run. Is there a way to
specify an interface w/o having to actually deploy a dll that just has
an interface specification in it?

Thanks,

Brad

9 Feb 2007 4:23 AM

Mike

On Feb 8, 7:30 pm, Brad Figler <bradfig***@gmail.com> wrote:
Show quote

> Here is my setup:
>
> I want a plugin interface for my application.
>
> I have my main app named App.exe
> I have a plugin interface assembly named PluginInterface.dll (defines
> IPluginInterface)
> I have a plugin implementation named PluginTest.dll (defines TestClass)
>
> In my application I simply do the following:
>
> Assembly myAssembly = Assembly.LoadFile( "PluginTest.dll" );
> IPluginInterface plugin = (IPluginInterface)myAssembly.CreateInstance(
> "TestClass" );
>
> plugin.Test() (one of the methods specified in the plugin interface).
>
> I compile the code and I get the following:
>
> MyApp.exe
> PluginInterface.dll
> PluginTest.dll
>
> If I delete PluginInterface, My code won't run. Is there a way to
> specify an interface w/o having to actually deploy a dll that just has
> an interface specification in it?
>
> Thanks,
>
> Brad

I believe that you can specify IPluginInterface within the MyApp.exe
project. Then, when you create your PluginTest.dll, you just have to
reference the MyApp project. The only time you would need the shared
middle dll is if you define a second interface that MyApp implements
so your plugin has some idea about the application using it.

Mike

9 Feb 2007 4:55 AM

Brad Figler

Mike wrote:
Show quote

> On Feb 8, 7:30 pm, Brad Figler <bradfig***@gmail.com> wrote:
>> Here is my setup:
>>
>> I want a plugin interface for my application.
>>
>> I have my main app named App.exe
>> I have a plugin interface assembly named PluginInterface.dll (defines
>> IPluginInterface)
>> I have a plugin implementation named PluginTest.dll (defines TestClass)
>>
>> In my application I simply do the following:
>>
>> Assembly myAssembly = Assembly.LoadFile( "PluginTest.dll" );
>> IPluginInterface plugin = (IPluginInterface)myAssembly.CreateInstance(
>> "TestClass" );
>>
>> plugin.Test() (one of the methods specified in the plugin interface).
>>
>> I compile the code and I get the following:
>>
>> MyApp.exe
>> PluginInterface.dll
>> PluginTest.dll
>>
>> If I delete PluginInterface, My code won't run. Is there a way to
>> specify an interface w/o having to actually deploy a dll that just has
>> an interface specification in it?
>>
>> Thanks,
>>
>> Brad
>
> I believe that you can specify IPluginInterface within the MyApp.exe
> project. Then, when you create your PluginTest.dll, you just have to
> reference the MyApp project. The only time you would need the shared
> middle dll is if you define a second interface that MyApp implements
> so your plugin has some idea about the application using it.
>
> Mike
>

Yeah, that is the "other" solution that I found during my time on google.

I don't necessarily want to do that because I have a bit of a funky
setup (from a development point of view).

The actual code that will use the plugin is a windows service. The
service entry point simply launches thread(s) that actually do the work
(and respond to the service manager requests). Well, the myApp.exe in
the above example is actually a test harness that includes all of the
code accept the entry point in to the service. This allows me to "run"
my services in normal program space while developing/debugging.

If I was to do that, I would have to put my plugin interface in my
service.exe and I don't want to do that because I want my test harness
to run independently of the service (and vice versa).

Long story short, I will just deal with the additional DLL.

Thanks for the response.

Brad