I know this question has been asked before but all the steps advised doesn't seem to work for me.
I am trying to use WebCamLib.dll to my project but it keeps giving me this error:
please make sure the file is accessible and that is a valid assembly
or com component
I tried to register the dll to SYSTEM32 and I get this error
The module C:\WebCamLib.dll" was loaded but the entry-point
DllRegisterServer was not found.
Make sure that "C:\WebCamLib.dll" is a valid DLL or OCX file and then
try again.
Please suggest a way. Thank you in advance.
The library you are trying to use is a managed library, you don't need to register it or use dllimport. Just add a reference from inside your project to the dll.
First option is DLL file may be corrupt. Make sure it is working with other applications.
My second opinion is you are trying to use this DLL as COM object which is not.
Related
I am trying to add a dll into my windows form application type project. However, when I am adding the dll to reference folder it is throwing an error and restricting me to add the same. Enclosed is a screenshot. Can anyone please let me know, under which condition we get this error and how to fix it?
Note: I am not aware, the dll has been produced using what tool or version/type of it.
screenshot of error
The message is:
A reference to C:\xyz.dll. dll could not be added, Please make sure
that the file is accessible and that it is a valid assembly or COM
component.
It's is exactly what you read and the message says.
Either thhis DLL doesn't contain any .NET code or class, or this DLL isn't a valid ActiveX DLL containing a typelib.
You can not add a DLL as a reference if it is not one of the above.
This is a possible duplicate to
I've been provided a DLL that has been written in C++. Along with the DLL I receive the required input parms and expected output as well as a .h include file.
Can't seem to get it included as a Reference in my project. My procedure is to right click References and Add Reference, click Browse and then double click on the DLL. The error I get is:
A reference to 'c:......\dll' could not be added. Please make sure
that the file is accessible, and that it is a valid assembly or COM
component.
The problem is likely due to the name mangling of C++, but I'm not sure how to overcome the problem. I've been told by the author of the DLL that it was written for another customer who ran into the same issue, but was eventually successful in getting it referenced. I don't have access to that 'customer' and was wondering if anyone had suggestions.
Adding a reference is not how you link to this unmanaged DLL from your C# code. Instead you need to either:
Translate the header file to C# p/invoke calls, or
Create a C++/CLI wrapper around the unmanaged DLL and add a reference to that from your C# project. This option would typically involve linking to the .lib import library for the DLL which should be supplied with the DLL.
I made an application in vs2010 (.net 4.0). I published it, both using publisher and InstallShield LE.
But when I run application, I get error that a dll is not found. I know which dll is missing. This is a non-COM object and I can't add it to my project in vs2010. I am using a wrapper library which invokes this dll.
If I paste that dll in syswow64, my application works fine. But I want a cleaner way of doing it. I already had a look at Hans's answer here. But I have no clue what is side-by-side cache.
Adding path to environment variables works fine too.
I am not sure if updating registry and adding a path value will work or not. I would like to know if I can update registry for my application and direct the path where it searches for particular dlls.
Thanks.
Modifying the user's PATH variable is a very heavyweight solution, and you should avoid that. Likewise, do not put the DLL in the system directory. That belongs to the system and is private to you.
The recommended way to solve the problem is simply to put the DLL in the same directory as the executable. The directory in which the executable lives is searched first when the loaded tries to locate DLLs. It is the safest place to put your native DLLs.
If for some reason you cannot put the DLL in the executable directory, there are other options:
Call SetDllDirectory with the directory of your DLL before making your first p/invoke call. When that call returns, call SetDllDirectory passing NULL to restore the default DLL search order.
Make an explicit call to LoadLibrary with the full path of your DLL before making your first p/invoke call. Once the DLL has been loaded, future p/invoke calls will use the module that has been loaded.
If you know the DLL name in advance, there is a simple way.
You can simply use LoadLibrary to load the DLL from its known location (based on for example a configuration file entry).
As long as you successfully call LoadLibrary before any of the DLL methods are used, this will succeed as the DLL is already loaded.
This works because you can LoadLibrary with a full path, and once that is done, subsequent calls to LoadLibrary with just the filename will succeed immediately, since the library is already loaded.
Preface: I know basically nothing about C#.
I've added a dll to my project. I have no build errors, but when I try to run, I get an error that says it can't find the dll. I've tried copying it to the output directories too. To no avail.
Any idea what could be happening?
Specific Error:
System.IO.FileNotFoundException was unhandled Message=Could not load
file or assembly 'controllib_clr.dll' or one of its dependencies. The
specified module could not be found. Source=controllib_demo_cs...
I'll be happy to add more information if need be. :) I just don't know what info would be beneficial given my (very) limited knowledge.
It looks like it is not able to find/load some dependencies dlls I will use DependencyWalker to figure out what it is missing http://www.dependencywalker.com/
Is it a managed (.NET) or an unmanaged (native) DLL? I'm assuming unmanaged.
FileNotFoundException is commonly thrown when missing a dependency. The DLL you are loading might require any number of other DLLs on load. In most cases it won't tell you which file it needs. You have to refer to the documentation for that DLL.
If it exists, in your output folder, then most likely its one of its dependencies that is missing. You can fix this by adding its dependencies as references in your project.
if it doesn't exist in your output, then, check that "Copy Local" is set in the properties of the reference.
I'm unable to open my project in Visual Studio 2008. It was developed in C# by my friend. It is showing the this error:
"Could not find type 'LibrarySystem.ctrlSeparator'.
Please make sure that the assembly that contains this type is referenced.
If this type is a part of your development project, make sure that
the project has been successfully built. "
Also
"The variable 'ctrlSeparator1' is either undeclared or was never assigned. "
How do I rectify this problem?
With all respect...the error message tells you everything you need to know...
It's trying to load a control, which does not exist. So either your friend didn't give you the whole project, or he used a Third-party-Component which you don't have.
Obviously your friend used (or wrote himself) a external library.
Ask him to provide you with this assembly, so that you can compile the project.
Either you don't have the complete project or you need to register dll. Make sure you have LibrarySystem.ctrlSeparator in code or assembly. If it is in unmanaged assembly then ask to friend whether it is needed to be registered.