ASP.NET and mapscript - unable to load DLL

[Tamas Szekeres]

Are you sure this error happens at the row you have mentioned? It seems
that you are using an object instance without calling "new" previously.
However Mapserver errors will result in an exception passed back through
the SWIG interface.

You should try to insantiate mapObj in a Windows test application. The
improper security context of aspnet_wp may also be a problem.

Tamas


On Fri, 19 Aug 2005 16:58:00 -0400, Mike Boos <mboos at AUGSIGNALS.COM> wrote:

>Thank you for that advice! I ran filemon and discovered that it was
>trying (unsuccessfully) to find libcurl.dll - which somehow didn't show
>up in my dependency tracking tool. It's now in my system path.
>
>I'm now running into new trouble. When I try to create a mapObj with
>"mapObj m_obj = new mapObj(mapfile);" I get the following error:
>
>
>    /Object reference not set to an instance of an object./
>
>* Description: *An unhandled exception occurred during the execution of
>the current web request. Please review the stack trace for more
>information about the error and where it originated in the code.
>
>* Exception Details: *System.NullReferenceException: Object reference
>not set to an instance of an object.
>
>Any suggestions?
>Mike
>
>Tamas Szekeres wrote:
>
>>Have you tried SysInternals's filemon or a similar program to monitor the
>>expected location of theese files?
>>
>>
>>
>>On Fri, 19 Aug 2005 13:23:38 -0400, Mike Boos <mboos at AUGSIGNALS.COM>
wrote:
>>
>>
>>
>>>mapscript_csharp.dll is present in the bin directory. All the others are
>>>in system32. gdal12.dll is in both as I'm somehow invoking a function
>>>
>>>
>>>from it from elsewhere and not having the slightest bit of trouble with
>>
>>
>>>that part (I'm using a direct DllImport attribute). So maybe I will have
>>>to try one of the alternatives. Oh well.
>>>
>>>Mike
>>>
>>>Abe Gillespie wrote:
>>>
>>>
>>>
>>>>Did you move mapscript.dll to system32 as well?  The only DLL that
>>>>should be in your bin dir is mapscript_csharp.dll.
>>>>
>>>>Suggestions:
>>>>1.  Write the mapfile by hand with the file streaming objects?
>>>>2.  Wrap the MapServer CGI executable with ASP.NET (I think someone
>>>>did just this some time ago).
>>>>3.  If this is all you're doing, you *might* be able to get away with
>>>>it in ASP.NET.  See if there's a way to protect a section of ASP.NET
>>>>code with a semaphore or similar construct.  Is there something that
>>>>protects in the virtual thread environment?
>>>>
>>>>-Abe
>>>>
>>>>On 8/19/05, Mike Boos <mboos at augsignals.com> wrote:
>>>>
>>>>
>>>>
>>>>
>>>>>I tried moving the dlls to the system32 directory, but that doesn't
have
>>>>>any effect (am I missing any other dependencies?)
>>>>>
>>>>>Unfortunately, I'm kind of stuck with ASP.NET, as that's what the rest
>>>>>of the site relies upon. I'm trying to improve the present setup which
>>>>>involves sending a request to a C++ CGI program which writes a map
file
>>>>>to the hard disk and forwards the request to mapserv.exe. If you'd ask
>>>>>me, that's a bit of a kluge, and without Mapscript, all I could do to
>>>>>improve on that would be to take out the C++ program and have the map
>>>>>file generated from within the ASP.NET program itself. Can you think
of
>>>>>a better way to accomplish the same task?
>>>>>
>>>>>Mike
>>>>>Abe Gillespie wrote:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>Placing the depended-on DLLs into the bin dir will do nothing.  I
>>>>>>assume you're on a windows box.  Therefore the easiest way to take
>>>>>>care of this is by placing all the DLLs (except for map_script) into
>>>>>><windows>\system32 where <windows> is the system windows directory
>>>>>>(c:\winnt, c:\windows, etc.).
>>>>>>
>>>>>>With that said, you're entering a world of pain by using C#
map_script
>>>>>>in ASP.NET.  Much of the map_script DLL is thread unsafe, that
>>>>>>combined with ASP.NET's supremely weird threading model (e.g. virtual
>>>>>>threads), you're going to encounter a plethora of problems.  This is
>>>>>>why you almost never see MapServer + ASP.NET discussion threads.
>>>>>>
>>>>>>To get more info, search the archives.  You should find ten or so
>>>>>>messages about this topic.
>>>>>>
>>>>>>-Abe
>>>>>>
>>>>>>On 8/18/05, Mike Boos <mboos at augsignals.com> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>Hello
>>>>>>>
>>>>>>>I'm trying to run Mapscript using the SWIG C# bindings on an ASP.NET
>>>>>>>server. I compiled the 4.6.0 version of MapServer and have placed
>>>>>>>
>>>>>>>
>>what I
>>
>>
>>>>>>>believe to be the appropriate dependencies (mapscript_csharp.dll,
>>>>>>>mapscript.dll, libmap.dll, bgd.dll, gdal12.dll, pdflib.dll) in the
bin
>>>>>>>directory on my server. It is appears to be finding
>>>>>>>mapscript_csharp.dll, but is having trouble finding mapscript.dll or
>>>>>>>
>>>>>>>
>>one
>>
>>
>>>>>>>of its dependencies. I am seeing the following error message:
>>>>>>>
>>>>>>>
>>>>>>>Server Error in '/' Application.
>>>>>>>
>>>>>>>
>>>>>>>  /Unable to load DLL (mapscript)./
>>>>>>>
>>>>>>>* Description: *An unhandled exception occurred during the execution
>>>>>>>
>>>>>>>
>>of
>>
>>
>>>>>>>the current web request. Please review the stack trace for more
>>>>>>>information about the error and where it originated in the code.
>>>>>>>
>>>>>>>* Exception Details: *System.DllNotFoundException: Unable to load
DLL
>>>>>>>(mapscript).
>>>>>>>
>>>>>>>Am I missing a dependency? Or do I need to set some configuration
>>>>>>>
>>>>>>>
>>option
>>
>>
>>>>>>>or place the files elsewhere?
>>>>>>>
>>>>>>>Thanks!
>>>>>>>Mike Boos
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
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