"Eric bouxirot" <ric***@rickou.net> wrote in message
news:mn.8b0c7d6930395ddf.56407@rickou.net...
> hi,
>
> i'd like to do a "cast", who seem to be very complicated in .NET. in C
> standard it's so easy...
>
> i explain :
> i have made an app based on plugin architecture in VB.NET. all work fine..
>
> but I want to avoid to the maximum to modify the interface at each new
> plugin feature request from main app, i defined a function like this :
>
>    Public Function Host_GetObject(ByVal FonctionName As String, Optional
> ByVal Parameters() As Object = Nothing) As Object() Implements
> ENPI.Interfaces.IHost.Host_GetObject
>
> this function get 1 parameter to tell witch "function" to do and 1 array
> of object (defined by the function) to optionals parameters of this
> function.
> this function return an array of object (content defined by the "function"
> entry parameter)
>
> i put this function in my interface between the main app and plugin. no pb
> at this point.
> if i use it with framework types, i get no problems.
>
> But now, i want to return (in the array of object) a simple data structure
> (no class !) like this :
>
>    Private Structure StrPIsName
>        Friend PIName As String
>        Friend PIAssyName As String
>    End Structure
>
> the main app can make the array of object from array of StrPIsName. good.
> in the plugin, i get the array of object. good too.. but each object is
> typed with mainapp.StrPIsName all this is normal.
>
> but for me, for raisons i tell before, i don't want to put the structure
> in the interface. (to avoid to recompil all plugin if i add or change the
> structure to the interface..)
>
> then, since my plugin does not have the reference to mainapp.StrPIsName
> but to it's own StrPIsName, the cast can't be made.
>
> do you understand what i mean ?
>
> the end goal is to be able to make some enhancement or changes in the main
> app and somme plugin or new plugins needs without the need to recompil all
> other plugins.
>
> i don't want to have many auxilliary DLL to get many interfaces between
> main app and plugins too.
>
> in fact, i want to do something (perhaps not good in .NET) like in
> standard C :
>
> toto = (mycast) tata;
>
> HELPPP !!
>
>

> Eric,
> First I would recommend this for your method:
>
>     Public Function Host_GetObject(ByVal FonctionName As String, ByVal
> ParamArray Parameters() As Object) As Object()
>
> Allowing you to call the method like:
>
>     Host_GetObject("method1", a)
>     Host_GetObject("method2", a, b)
>     Host_GetObject("method3")
>     Host_GetObject("method1", a, b, c, d, e)
>
> and even:
>     Dim args() As Object
>     Host_GetObject("method1", args)
>
> Without needing to explicitly create an array of object. The ParamArray
> causes an object array to be implicitly created, unless you explicitly pass
> an array of object.
>

>> in the plugin, i get the array of object. good too.. but each object is
>> typed with mainapp.StrPIsName all this is normal.
>
> .NET is a managed strongly typed runtime. An value of MainApp.StrPIsName is
> distinct from a value of SomeAddin.StrPIsName. .NET does not look at the
> sequence of fields in a type to decide equivalence. instead it looks at the
> type's name, it's namespace, it's assembly, and even the assembly's version
> when deciding if a cast is allowed. Which means that
>
>>    Private Structure StrPIsName
>>        Friend PIName As String
>>        Friend PIAssyName As String
>>    End Structure
>
> in two assemblies (MainApp & SomeAddin) are distinct types & cannot be cast
> between each other.
>