没有使用反射的运行时C＃“找不到方法”异常

Question

I have a problem with getting above exception. I have a relatively simple structure separate in two dll.

First one contains a IEntityService, IEntity, with basic implementation. Second one contains the actual implementations as well as interfaces. so there is a IMachine service which implements IEntityService and MachineService which implements both IEntityService and EntityService. Similar situation happen for a Result collection( entity plus service). Additionally the service(Machine and result) are partial classes/interfaces where one of the class is auto generated.

Now in one of the ResultMachine I am trying to get a machine and in a case it do not exists I am creating it and saving. However when I am trying to save I got the "Method not found" when trying to access a saving method from a EntityService class. However if I wrap EntityService.Save method in a MachineService it is working without any exception.

Edited:

The code is not required. THe resolution was to re-link the reference. What was misleading for me that my dll is not in GAC, it is linked with VS. What is more it is not strongly signed, the only difference is version number.

Answer 1

We have got this error a few times, you can recreate the problem as follows:

• Created project with 2 dll's (say a program dll and a test dll)
• deploy program dll to GAC
• Add new method
• Create test to test the new method
• build solution
• run test (not in debug mode)

You will now get the method missing exception. The reason is that it is using the old version of the dll that is in GAC and does not have the method.

Some times it uses a cached version of the old dll, IISreset can help.

In your case check for any old versions of the dll.

Answer 2

My first instinct would be to check to make sure the assemblies contained the classes with the missing method. I suppose its possible that the assembly didn't get updated immediately?

Answer 3

When referencing the "same" type from different assemblies, make sure you are loading everything via the same path. Otherwise, identical types can actually be treated as if they are different.

See this article for more: Fusion Loader Contexts - Unable to cast object of type 'Whatever' to type 'Whatever'

Answer 4

This happened to me when I went in and tweaked my build settings to output to /bin/Debug rather than to just /bin in a case when I was also using IIS to host the site from the dev folder.

You need to have the binaries in the same folder as the service, in my case, and the tweak left old versions in the bin folder and put subsequent builds into the /bin/Debug folder (and /bin/Release).

Either keep the settings as is and have a post build action to copy the bits up one level, have different IIS applications for debug/release, or deploy to another folder altogether. The latter is probably most "correct" but for my purposes I just realized after much wheel-spinning, that I had different versions in the service's folder. HTH.

Answer 5

In my case I just deployed on a machine with .NET 3.0 (Windows XP) while the compile target has been .NET 3.5.

This error message is really not helpful.

Problem has been usage of DataContract from System.Runtime.Serialisation.