TypeLoadException

[Eric B]

I have created a DLL. It builds successfully without warnings.
I created an app that refereneces the DLL and it too builds.

However, when ever I try to use an object in the DLL
I get a "TypeLoadException", something like:
"Could not load type <name> from assembly <assembly name>"

Could someone tell me some common mistakes that result in this error?

Thank you in advance,
Eric

[Barry Kelly]

"Eric B" <bo*********@invalid.com> wrote:

I have created a DLL. It builds successfully without warnings.
I created an app that refereneces the DLL and it too builds.

However, when ever I try to use an object in the DLL
I get a "TypeLoadException", something like:
"Could not load type <name> from assembly <assembly name>"

Could someone tell me some common mistakes that result in this error?

If you have an old version of the DLL which no longer exports the type,
and it is on the path (i.e. typically in the same directory) as the
program, then the program will give this error.

Is the .DLL file definitely up to date? Is the class library project
part of the same solution as the executable, so that VS does all the
required dependencies and copying? Try running .NET Reflector on the DLL
and checking that the type you're loading is in fact in from the DLL.

-- Barry

--
http://barrkel.blogspot.com/

[Eric B]

Thanks for the feedback.
I assumed that if a reference was added and the DLL was
modified that the reference was still valid. I now have to
remove and add the reference everytime the DLL is modified
to avoid the problem.
This however is quite annoying. Is there a way to avoid this?
Thanks
Eric
"Barry Kelly" <ba***********@gmail.com> wrote in message
news:nt********************************@4ax.com...

"Eric B" <bo*********@invalid.com> wrote:

I have created a DLL. It builds successfully without warnings.
I created an app that refereneces the DLL and it too builds.

However, when ever I try to use an object in the DLL
I get a "TypeLoadException", something like:
"Could not load type <name> from assembly <assembly name>"

Could someone tell me some common mistakes that result in this error?

If you have an old version of the DLL which no longer exports the type,
and it is on the path (i.e. typically in the same directory) as the
program, then the program will give this error.

Is the .DLL file definitely up to date? Is the class library project
part of the same solution as the executable, so that VS does all the
required dependencies and copying? Try running .NET Reflector on the DLL
and checking that the type you're loading is in fact in from the DLL.

-- Barry

--
http://barrkel.blogspot.com/

[Barry Kelly]

"Eric B" <bo*********@invalid.com> wrote:

Thanks for the feedback.
I assumed that if a reference was added and the DLL was
modified that the reference was still valid. I now have to
remove and add the reference everytime the DLL is modified
to avoid the problem.
This however is quite annoying. Is there a way to avoid this?

Are the two projects part of the same solution? If they are, and you've
added the reference in the correct way (i.e. Add Reference | Projects
tab), then VS handle this automatically.

-- Barry

--
http://barrkel.blogspot.com/

[Eric B]

Thanks again Barry,

I test the DLL with a test application that is part of the
same project as the DLL and seem to experience the issue.
I know this because I made some visual changes to a dialog
that was part of the DLL and those changes did not appear
until I removed and then readded the DLL using a slightly
different way to add it as follows:
Add Reference | Browse
I'll try your recommendation and see if this changes things.

Eric

"Barry Kelly" <ba***********@gmail.com> wrote in message
news:34********************************@4ax.com...

"Eric B" <bo*********@invalid.com> wrote:

Thanks for the feedback.
I assumed that if a reference was added and the DLL was
modified that the reference was still valid. I now have to
remove and add the reference everytime the DLL is modified
to avoid the problem.
This however is quite annoying. Is there a way to avoid this?

Are the two projects part of the same solution? If they are, and you've
added the reference in the correct way (i.e. Add Reference | Projects
tab), then VS handle this automatically.

-- Barry

--
http://barrkel.blogspot.com/