C# ODP.NET Load file or assembly - c#

I recently started testing on a C# (4.0) app that uses ODP.NET (Oracle.DataAccess 4.112.3)
I set this project to target any platform and publish the app.
When I run the program on the client machine I receive:
Could not load file or assembly 'Oracle.DataAccess, Version=4.112.3.0,Culture=neutral,
PublicKeyToken=89b483f429c47342' or one of its dependencies. An attempt was made to load
a program with an incorrect format.
Like I said I've targeted 'Any CPU' and I've also embedded the Oracle.DataAccess assembly with the app.
I get this error on machines that have the Oracle client installed as well as machines that do not.
Any help is appreciated.

Like I said I've targeted 'Any CPU'
This is likely the problem.
The Oracle.DataAccess has separate versions for 32bit and 64bit systems. If you are developing on a 32bit machine, and then deploying on a 64bit OS, you will receive this message.
You could easily work around this by building your application to target x86, and deploying the 32bit version of the data access components.

As Reed Copsey said, there are two different DLLs. When you target ANYCpu, your app will run in 64 bit on a 64 bit machine, and 32 bit on a 32 bit machine. Therefore, if you want your app to work on 32 or 64 bit and run in AnyCPU mode, you should change the reference of Oracle.DataAccess to Specific Version=false and copy local = false. When you deploy to a client, they should have the oracle dll in the their GAC and it should pick up the correct version automagically.

You should perhaps check if the Oracle.DataAccess assembly has any dependencies in your machine and that it is missing in the client machine.

From debug Any cpu at top change the optin to debug X64, though internally Any CPu points to X64 only but that does not work, try to change it to x64 and it should work like a charm

Related

Any concerns when switching from 32 to 64 bit Windows Services?

I have several Windows Services that target 32-bit but have been running on a 64-bit OS. I want to benefit from the advantages of 64-bit processes, specifically from a memory standpoint. Outside of changing the platform target from 32 bit to 64 bit, is there anything else I need to do or watch out for?
The answer is - depends. You said:
I have several Windows Services that target 32-bit but have been running on a 64-bit OS
If you build your app targeting x86 - you still run 32-bit even on 64-bit machine.
If you will build your service for AnyCPU, your exe will behave as following:
on 32 bit systems it will attempt to load as x86 and all components must be either x86 or AnyCpu
on 64 bit systems it will attempt to load x86-built assembly as x86 and all components MUST be only x86. And if you have some COM or 3rd party - you may have to compile for x86
on 64 bit systems it will load AnyCPU into x64 context and you better have NO dependencies built for x86. Also, you can build for x64, optimized code.
So, to answer your concrete original sentence - you will need (at minimum) to target AnyCPU or x64 in order to run your app in x64 context. If it is built targeting x86 - you are still running in 32 bit context
Just ensure that all references you use in your Windows Services are also compiled under 'Any' target, otherwhise you will face a problem when trying to load 32bit assemblies in a 64bit Service.

How do I reference a 32 bit DLL in a 64 bit project?

I've got a C# 2.0 project which is set to target 'Any Cpu', however it is referencing a C++ project that's building a 32 bit dll.
When I try to run my program on a 64bit machine I get the following error:
System.BadImageFormatException was
unhandled Message: Could not load file
or assembly TreeTMHook,
Version=1.0.2889.19619,
Culture=neutral, PublicKeyToken=null
or one of its dependencies. An attempt
was made to load a program with an
incorrect format.
How can I fix this?
Update
I want to be able to keep the main project as any cpu.
Thanks.
You'll need to build your .NET project as 32bit (x86 target) if you want it to correctly load a 32-bit DLL on a 64bit machine.
RE: Update:
If you want to keep your project as "Any CPU", you'll need a 32bit and a 64bit version of the DLL, and make sure the appropriate version is distributed with your app. If you can't build the other project as 64bit, you must build your .NET project as 32-bit only.
You will have to force your EXE project to run in 32-bit mode so it can use that C++ DLL. Project + Properties, Build tab, Platform Target = x86.
You may want to take a look at this article it explains why it is not possible, in short since you are dealing with pointers when accessing unmanaged code.
To keep you main project as Any Cpu, you need to supply both 32 and 64 bit version of the .dll - which should be possible, seeing as you're building it from source.
You then need to supply the executable with a manifest pointing it toward to right dll verion depending on platform.
Please use .net reflection and consume objects and its methods. Instead of direct 32 bit dll reference.

Attempt to use DLL results in error

I am using a library (DLL) that uses the Oracle.DataAccess DLL to connect to the database.
I am doing in in C# .NET framework 3.5
When I attempt to compile, the compilation takes place, but the executable throws this error message.
Could not load file or assembly 'Oracle.DataAccess, Version=2.111.7.20, Culture=
neutral, PublicKeyToken=89b483f429c47342' or one of its dependencies. An attempt
was made to load a program with an incorrect format.
Is there some way to get around this? What could be causing this to happen?
The dll for that ODBC is likely a 32bit only dll. Are you using this on a 64bit machine? If you are, IIS 7 has an option in the application pool that will allow you to "Enable 32-Bit Applications".
One possibility: Your programm is compiled with x64 or AnyCPU on a 64bit machine but the dll has been compiled with support for x86 only.
You can overcome this if you change the plattform of your Solution (or project) to x86.
I know you can force a 64bit Assembly to run as a 32bit app with:
corflags /32bit+ Oracle.DataAccess.dll
That works because the MSIL code is not bound to a processor architecture. However I never tried it the other way:
corflags /64bit+ Oracle.DataAccess.dll
so I can't tell if this works. And I propably won't work if the dll has unmanaged dependencies.

Read Excel files from C# in 64 bit version server

reading excel files from C# working well in 32 bit version server. It is not working in 64 bit version (Windows 2003 server), because excel data connection dll not supported in 64 bit version.
Is any other option available ?
In your project properties set the target platform from 'Any' to 'x86'.
Details:
In Windows x64 a process may be started as 32bit or 64bit process. A 64bit process can only load 64bit dlls and a 32bit process only 32bit dlls.
If your platform target (e.g. specified in the project properties) of your .Net application is set to "Any CPU", the intermediate code will be compiled to 32bit or 64bit code depending on the target platform, i.e. on a x64 system 64bit code will be generated.
Therefore the code can no longer load a 32bit dll.
If your code loads unmanaged assemblies you should always specify the target platform explicitly

How to load a specific version of an assembly

To complete some testing I need to load the 64 bit version of an assembly even though I am running a 32 bit version of Windows. Is this possible?
I'm not sure why you would want to do this, but I suppose you could. If you don't do anything to tell it otherwise, the CLR will load the version of the assembly that is specific to the CPU you are using. That's usually what you want. But I have had an occasion where I needed to load the neutral IL version of an assembly. I used the Load method to specify the version. I haven't tried it (and others here suggest it won't work for an executable assembly), but I suppose you can do the same to specify you want to load the 64 bit version. (You'll have to specify if you want the AMD64 or IA64 version.)
From CLR Via C# (Jeff Richter):
"If your assembly files contain only type-safe managed code,
you are writing code that should work on both 32-bit and 64-bit versions of Windows. No
source code changes are required for your code to run on either version of Windows.
In fact,
the resulting EXE/DLL file produced by the compiler will run on 32-bit Windows as well as
the x64 and IA64 versions of 64-bit Windows! In other words, the one file will run on any
machine that has a version of the .NET Framework installed on it."
" The C# compiler offers a /platform command-line switch. This switch allows you to specify
whether the resulting assembly can run on x86 machines running 32-bit Windows versions
only, x64 machines running 64-bit Windows only, or Intel Itanium machines running 64-bit
Windows only. If you don't specify a platform, the default is anycpu, which indicates that the
resulting assembly can run on any version of Windows.
32 bit Windows can not run 64 bit executables without a VM/emutalor
32 bit Windows can compile for execution on 64 bit Windows
No, you cannot run assemblies that are compiled for 64-bit on a system running the 32-bit version of Windows.

Categories

Resources