Suzanne Cook's .NET CLR Notes

I use LoadFrom() to load an assembly and register the remotable types included therein. I make a call to one of these remotable types from a remote client and it fails UNLESS I put the assembly in the same directory as the host (executable). It's as if the path that was provided for the LoadFrom() is ignored by the host when it comes time to actually service a remoting call. But this seems odd, doesn't the assembly stay loaded after my LoadFrom() call? Why would it have to look for the DLL file, since I already loaded it? I must be missing something...

Thanks!

From my tests, LoadWithPartialName has the same semantics as Load. Am I right?

Thanks

Jon Flanders posts here about a problem he diagnosed recently about Assembly.LoadFrom() and Assembly.Load() behaving differently. The issue he basically...

from a config file like this

 <!-- Create skeleton document -->

       <component type="Microsoft.Ddue.Tools.CopyFromFileComponent" assembly="%DXROOT%\ProductionTools\BuildComponents.dll">

         <data file="%DXROOT%\Presentation\Prototype\transforms\skeleton.xml" />

         <copy source="/*" target="/" />

       </component>

i am using Assembly.LoadFrom() to load the assembly and most oft he entries in my config file point to same assembly like BuildComponents.dll.

Will there be a huge perf gain if it load otonce and use that refernce than loadign it everytime?

In the project i am working on i am using alot of reflection.

I was having a problem with one of my reflection aspects where i was reading the types from

foreach(string dll in dllsInBinDirectory)

{

 Assembly assemb = Assembly.LoadFile(dll)

 readAssembly(assemb);  

}

List<ScheduleTask> ScheduleTasks = new List<ScheduleTask>;

readAssembly(Assembly assemb) {

foreach(Type t in Assemb.getTypes()) {

if(type.Base.Name=="ScheduleTask")

{

object st = Activator.CreateInstance(type);

//I was having a problem casting here

//InvalidCastException: Unable to cast //object /of Type 'X' to 'X'

scheduleTasks.Add((ScheduleTask)type);

Even though the object was of the same type, and it seemed like the type was coming from the same Assembly, there locations where different (One Assembly was in the temporary folder) and one was in the Bin folder.

i found this link

http://www.infini-tec.de/post/2008/05/InvalidCastException-Unable-to-cast-object-of-Type-X-to-X.aspx

and Move from Assembly.LoadFile

to Assembly.LoadFrom

and it solved! but am i write using it in this context?

}

}

}

Hi Suzanne.

I've a problem binding assemblies to my Excel-C# AddIn.

I have to do late binding and try this like follows:

public static object CreateInstanceFromExternalType( string assemblyPath, string typeName )

       {

           try

           {

               // Externe Assembly laden

               Environment.CurrentDirectory = System.IO.Path.GetDirectoryName( assemblyPath );

               Assembly externalAssembly = Assembly.LoadFile( assemblyPath, new Evidence( Assembly.GetExecutingAssembly().Evidence ) );

               // get Typeinformation

               Type externalType = externalAssembly.GetType( typeName );

               // create Instance

               return Activator.CreateInstance( externalType );

           }

            catch ( Exception ex )

           {

               throw ex;

           }

       }

Sometimes this runs and sometimes it crashes.

My Problem is, that I have to load an assembly from a third party vendor. He says, that his dlls have static linked dependencies and therefore it is absolutely neccessary to lod the original dll.

obviously excel sometimes loads a temporarily copied dll and then the dependencies are missing.

Because of your blog I tried to use Assembly.ReflectionOnlyLoadFrom( assemblyPath ) but then Activator.CreateInstance crashes.

Is there any way to just load the original dll?

thanks Tele