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how to query gac for assembly files

I am trying to learn more about Reflection, and took some code already built and added to it. Now I am trying to query the GAC for other assemblies and build type instances, and etc. I modified the code I found here, but myAssemblyList is empty. Can you tell me what I am doing wrong? I debugged and placed a break at "var currentAssembly = value.GetAssembly(f);" and it returns null. All the code I have seen populates Assemblies from the current AppDomain, but I have seen methods like LoadFrom(), which should work with a directory path. I also saw this post, and compiled it.
class Program
{
static void Main(string[] args)
{
AppDomainSetup domaininfo = new AppDomainSetup();
domaininfo.ApplicationBase = System.Environment.CurrentDirectory;
Evidence adevidence = AppDomain.CurrentDomain.Evidence;
AppDomain domain = AppDomain.CreateDomain("MyDomain", adevidence, domaininfo);
Type type = typeof(Proxy);
var value = (Proxy)domain.CreateInstanceAndUnwrap(
type.Assembly.FullName,
type.FullName);
//String myDir = "C:\\Windows\\Microsoft.NET\\assembly\\GAC_64\\";
String myDir = "C:\\Windows\\Microsoft.NET\\assembly\\";
List<Assembly> myAssemblyList = new List<Assembly>();
foreach (String f in Directory.GetFiles(myDir, "*.dll", SearchOption.AllDirectories))
{
//Console.WriteLine($"Here is f: {f}");
var currentAssembly = value.GetAssembly(f);
if (currentAssembly != null)
{
myAssemblyList.Add(currentAssembly);
Console.WriteLine(currentAssembly.FullName);
//Console.ReadLine();
}
Console.WriteLine($"Total Assemblies found: {myAssemblyList.Count}");
}
Console.WriteLine($"Total Assemblies found: {myAssemblyList.Count}");
Console.ReadLine();
}
}
public class Proxy : MarshalByRefObject
{
public Assembly GetAssembly(string assemblyPath)
{
try
{
return Assembly.LoadFile(assemblyPath);
}
catch (Exception)
{
return null;
// throw new InvalidOperationException(ex);
}
}
}
I jumped one directory back, and tried to collect from GAC_* i.e. 32, 64, and MSIL. I added a test for null for currentAssembly to address an issue with GetAssembly(). But still some directories that contain dll and non-dll files cause exceptions.

modify this line:
foreach (String f in Directory.GetFiles(myDir))
with
foreach (String f in Directory.GetFiles(myDir, "*.dll", SearchOption.AllDirectories)

Assembly reflection loading and app domain conflict

I am trying to make a small C# tool to compare two svn revision builds and track properties changes in any classes. My goal is to use reflection to compare the properties of each class of my dll without using Momo.Cecil.
From experimenting, then reading this article Assembly Loading and a few threads found on Google, I learnt that two DLLs with same identities would get resolved as the same if we dont use Assembly.ReflectionOnlyLoadFrom.
Trying to use their code to create an AppDomain for each loading, and also try many variants from searches, I get this exception and I can't find any thread explaining how to solve this issue:
API restriction: The assembly 'file:///D:\somepath\82\MyLib.dll' has already loaded from a different location. It cannot be loaded from a new location within the same appdomain.
This error happen on the 2nd call (the path 82) on the following line:
Assembly assembly = Assembly.ReflectionOnlyLoadFrom(assemblyPath);
Maybe I din't understand something very basic which make me unable to create a new AppDomain correctly?
Here is all the code used to reproduce this problem.
Code from my entry point
//Let say one of the property has been renamed between both commits
var svnRev81Assembly = ReflectionOnlyLoadFrom(#"D:\somepath\81\MyLib.dll");
var svnRev82Assembly = ReflectionOnlyLoadFrom(#"D:\somepath\82\MyLib.dll");
Implementation of the loader
private string _CurrentAssemblyKey;
private Assembly ReflectionOnlyLoadFrom(string assemblyPath)
{
var path = Path.GetDirectoryName(assemblyPath);
// Create application domain setup information.
AppDomainSetup domaininfo = new AppDomainSetup();
domaininfo.ApplicationBase = path;
domaininfo.PrivateBinPath = path;
_CurrentAssemblyKey = Guid.NewGuid().ToString();
AppDomain currentAd = AppDomain.CreateDomain(_CurrentAssemblyKey, null, domaininfo); //Everytime we create a new domain with a new name
//currentAd.ReflectionOnlyAssemblyResolve += CustomReflectionOnlyResolver; This doesnt work anymore since I added AppDomainSetup
currentAd.SetData(_CurrentAssemblyKey, path);
//Loading to specific location - folder 81 or 82
Assembly assembly = Assembly.ReflectionOnlyLoadFrom(assemblyPath);
//Preloading the
foreach (var assemblyName in assembly.GetReferencedAssemblies())
{
Assembly.ReflectionOnlyLoadFrom(Path.Combine(path, assemblyName.Name + ".dll"));
}
Type[] types = assembly.GetTypes();
// Lastly, reset the ALS entry and remove our handler
currentAd.SetData(_CurrentAssemblyKey, null);
//currentAd.ReflectionOnlyAssemblyResolve -= CustomReflectionOnlyResolver; This doesnt work anymore since I added AppDomainSetup
return assembly;
}

This can solved by loading dlls in seperate appdomain.
private static void ReflectionOnlyLoadFrom()
{
var appDomain = AppDomain.CreateDomain("Temporary");
var loader1 = (Loader)appDomain.CreateInstanceAndUnwrap(typeof(Loader).Assembly.FullName, typeof(Loader).FullName);
loader1.Execute(#"D:\somepath\81\MyLib.dll");
var loader2 = (Loader)appDomain.CreateInstanceAndUnwrap(typeof(Loader).Assembly.FullName, typeof(Loader).FullName);
loader2.Execute(#"D:\somepath\82\MyLib.dll");
loader1.CompareTwoDLLs(loader2);
AppDomain.Unload(appDomain);
}
Loader.cs
public class Loader : MarshalByRefObject
{
public Assembly TempAssembly { get; set; }
public string Execute(string dllPath)
{
TempAssembly = Assembly.LoadFile(dllPath);
return TempAssembly.FullName;
}
public void GetRefAssemblyTypes()
{
foreach (var refAssembly in TempAssembly.GetReferencedAssemblies())
{
var asm = Assembly.Load(refAssembly);
var asmTypes = asm.GetTypes();
}
}
public void CompareTwoDLLs(Loader l2)
{
var types1 = TempAssembly.GetTypes();
var types2= l2.TempAssembly.GetTypes();
GetRefAssemblyTypes();
//logic to return comparison result
}
}

Re-load Unloaded Projects in EnvDTE

I have listed all the projects in my solution, using EnvDTE, but I found a bug in my code: I can't get the projects that are Unloaded.
I found a way to skip the Unloaded projects:
if (string.Compare(EnvDTE.Constants.vsProjectKindUnmodeled, project.Kind, System.StringComparison.OrdinalIgnoreCase) == 0)
continue;
This way, my code doesn't crash - but I am unable to load the missing projects through code, since they exist already.
How can I Load the Unloaded projects into the solution ?
I have tried:
project.DTE.ExecuteCommand("Project.ReloadProject");
And got error:
System.Runtime.InteropServices.COMException (...): Command "Project.ReloadProject" is not available.
So I tried to somehow get
application.DTE.ExecuteCommand("Project.ReloadProject");
But before that, from every place I searched on the NET, I must pre-select the project in the solution - and for that, I need project.Name (which I have), and the path, which I don't (every example I have found assumes that the solution path is the same as the project path, which is highly unlikely in a generic situation).

The Visual Studio SDK is apparently the way to do this.
var dte = (EnvDTE.DTE)System.Runtime.InteropServices.Marshal.GetActiveObject("VisualStudio.DTE");
Microsoft.VisualStudio.Shell.Interop.IVsUIHierarchyWindow hierarchy;
ServiceProvider sp = new ServiceProvider((Microsoft.VisualStudio.OLE.Interop.IServiceProvider)dte);
IVsSolution sol = (IVsSolution)sp.GetService(typeof(SVsSolution));
foreach (ProjInfo info in GetProjectInfo(sol))
{
info.Dump();
}
//from http://social.msdn.microsoft.com/Forums/en-US/vsx/thread/60fdd7b4-2247-4c18-b1da-301390edabf3/
static IEnumerable<ProjInfo> GetProjectInfo(IVsSolution sol)
{
Guid ignored = Guid.Empty;
IEnumHierarchies hierEnum;
if (ErrorHandler.Failed(sol.GetProjectEnum((int)__VSENUMPROJFLAGS.EPF_ALLPROJECTS, ref ignored, out hierEnum)))
{
yield break;
}
IVsHierarchy[] hier = new IVsHierarchy[1];
uint fetched;
while ((hierEnum.Next((uint)hier.Length, hier, out fetched) == VSConstants.S_OK) && (fetched == hier.Length))
{
int res = (int)VSConstants.S_OK;
Guid projGuid;
if (ErrorHandler.Failed(res = sol.GetGuidOfProject(hier[0], out projGuid)))
{
Debug.Fail(String.Format("IVsolution::GetGuidOfProject returned 0x{0:X}.", res));
continue;
}
string uniqueName;
if (ErrorHandler.Failed(res = sol.GetUniqueNameOfProject(hier[0], out uniqueName)))
{
Debug.Fail(String.Format("IVsolution::GetUniqueNameOfProject returned 0x{0:X}.", res));
continue;
}
if( System.IO.Path.GetInvalidPathChars().Any (p =>uniqueName.Contains(p) ))
{
uniqueName.Dump("invalid filename found");
yield return new ProjInfo(projGuid,uniqueName);
}
else {
yield return new ProjInfo(projGuid, Path.GetFileName(uniqueName).BeforeOrSelf("{"));
}
}
}
got most of it from http://social.msdn.microsoft.com/Forums/en-US/vsx/thread/60fdd7b4-2247-4c18-b1da-301390edabf3/

c# path of localized resources for plugin DLLs

In my C# application, I've a plugin mechanism that loads plugin DLLs from different pathes as specified in a configuration XML file. My application is localizable. The main assembly (the *.exe) has satellite assemblies for the localized languages next to the exe in the standard .NET way (e.g. .\en\en-US\main.resources.dll; .\de\de_DE\main.resources.dll; etc.).
I started localizing a plugin and had to discover that the satellite assembly has to be put in the folders next to the exe. When putting it next to the plugin DLL, the resource manager doesn't find it.
However, since my plugins are interchangable and potentially in different folders, I would highly prefer to put the localized resource assemblies next to the plugins and not to the exe.
Is this possible?!?!
An alternative I could live with would be to embed the localized resources into the DLLs. Is this possible??
Cheers,
Felix

I ran into this issue when working on a product for our company. I didn't find an answer anywhere, so I'm going to post my solution to it here in case someone else finds themselves in the same situation.
As of .NET 4.0 there is a solution to this issue, because satellite assemblies now get passed to the AssemblyResolve handler. If you already have a plugin system where assemblies can be loaded from remote directories, you'll probably already have an assembly resolve handler in place, you just need to extend it to use a different search behaviour for satellite resource assemblies. If you don't have one, the implementation is non-trivial since you basically take responsibility for all assembly search behaviour. I'll post the complete code for a working solution so either way you'd be covered. First of all, you need to hook your AssemblyResolve handler somewhere, like this:
AppDomain.CurrentDomain.AssemblyResolve += ResolveAssemblyReference;
Then assuming you've got a couple of variables to hold path information for your main application and your plugin directories, like this:
string _processAssemblyDirectoryPath;
List<string> _assemblySearchPaths;
Then you need a little helper method that looks a little like this:
static Assembly LoadAssembly(string assemblyPath)
{
// If the target assembly is already loaded, return the existing assembly instance.
Assembly[] loadedAssemblies = AppDomain.CurrentDomain.GetAssemblies();
Assembly targetAssembly = loadedAssemblies.FirstOrDefault((x) => !x.IsDynamic && String.Equals(x.Location, assemblyPath, StringComparison.OrdinalIgnoreCase));
if (targetAssembly != null)
{
return targetAssembly;
}
// Attempt to load the target assembly
return Assembly.LoadFile(assemblyPath);
}
And finally you need the all important AssemblyResolve event handler, which looks a little something like this:
Assembly ResolveAssemblyReference(object sender, ResolveEventArgs args)
{
// Obtain information about the requested assembly
AssemblyName targetAssemblyName = new AssemblyName(args.Name);
string targetAssemblyFileName = targetAssemblyName.Name + ".dll";
// Handle satellite assembly load requests. Note that prior to .NET 4.0, satellite assemblies didn't get
// passed to AssemblyResolve handlers. When this was changed, there is a specific guarantee that if null is
// returned, normal load procedures will be followed for the satellite assembly, IE, it will be located and
// loaded in the same manner as if this event handler wasn't registered. This isn't sufficient for us
// though, as the normal load behaviour doesn't correctly locate satellite assemblies where the owning
// assembly has been loaded using Assembly.LoadFile where the assembly is located in a different folder to
// the process assembly. We handle that here by performing the satellite assembly search process ourselves.
// Also note that satellite assemblies are formally documented as requiring the file name extension of
// ".resources.dll", so detecting satellite assembly load requests by comparing with this known string is a
// valid approach.
if (targetAssemblyFileName.EndsWith(".resources.dll"))
{
// Retrieve the owning assembly which is requesting the satellite assembly
string owningAssemblyName = targetAssemblyFileName.Replace(".resources.dll", ".dll");
Assembly owningAssembly = AppDomain.CurrentDomain.GetAssemblies().FirstOrDefault((x) => x.Location.EndsWith(owningAssemblyName));
if (owningAssembly == null)
{
return null;
}
// Retrieve the directory containing the owning assembly
string owningAssemblyDirectory = Path.GetDirectoryName(owningAssembly.Location);
// Search for the required satellite assembly in resource subdirectories, and load it if found.
CultureInfo searchCulture = System.Threading.Thread.CurrentThread.CurrentCulture;
while (searchCulture != CultureInfo.InvariantCulture)
{
string resourceAssemblyPath = Path.Combine(owningAssemblyDirectory, searchCulture.Name, targetAssemblyFileName);
if (File.Exists(resourceAssemblyPath))
{
Assembly resourceAssembly = LoadAssembly(resourceAssemblyPath);
if (resourceAssembly != null)
{
return resourceAssembly;
}
}
searchCulture = searchCulture.Parent;
}
return null;
}
// If the target assembly exists in the same directory as the requesting assembly, attempt to load it now.
string requestingAssemblyPath = (args.RequestingAssembly != null) ? args.RequestingAssembly.Location : String.Empty;
if (!String.IsNullOrEmpty(requestingAssemblyPath))
{
string callingAssemblyDirectory = Path.GetDirectoryName(requestingAssemblyPath);
string targetAssemblyInCallingDirectoryPath = Path.Combine(callingAssemblyDirectory, targetAssemblyFileName);
if (File.Exists(targetAssemblyInCallingDirectoryPath))
{
try
{
return LoadAssembly(targetAssemblyInCallingDirectoryPath);
}
catch (Exception ex)
{
// Log an error
return null;
}
}
}
// If the target assembly exists in the same directory as the process executable, attempt to load it now.
string processDirectory = _processAssemblyDirectoryPath;
string targetAssemblyInProcessDirectoryPath = Path.Combine(processDirectory, targetAssemblyFileName);
if (File.Exists(targetAssemblyInProcessDirectoryPath))
{
try
{
return LoadAssembly(targetAssemblyInProcessDirectoryPath);
}
catch (Exception ex)
{
// Log an error
return null;
}
}
// Build a list of all assemblies with the requested name in the defined list of assembly search paths
Dictionary<string, AssemblyName> assemblyVersionInfo = new Dictionary<string, AssemblyName>();
foreach (string assemblyDir in _assemblySearchPaths)
{
// If the target assembly doesn't exist in this path, skip it.
string assemblyPath = Path.Combine(assemblyDir, targetAssemblyFileName);
if (!File.Exists(assemblyPath))
{
continue;
}
// Attempt to retrieve detailed information on the name and version of the target assembly
AssemblyName matchAssemblyName;
try
{
matchAssemblyName = AssemblyName.GetAssemblyName(assemblyPath);
}
catch (Exception)
{
continue;
}
// Add this assembly to the list of possible target assemblies
assemblyVersionInfo.Add(assemblyPath, matchAssemblyName);
}
// Look for an exact match of the target version
string matchAssemblyPath = assemblyVersionInfo.Where((x) => x.Value == targetAssemblyName).Select((x) => x.Key).FirstOrDefault();
if (matchAssemblyPath == null)
{
// If no exact target version match exists, look for the highest available version.
Dictionary<string, AssemblyName> assemblyVersionInfoOrdered = assemblyVersionInfo.OrderByDescending((x) => x.Value.Version).ToDictionary((x) => x.Key, (x) => x.Value);
matchAssemblyPath = assemblyVersionInfoOrdered.Select((x) => x.Key).FirstOrDefault();
}
// If no matching assembly was found, log an error, and abort any further processing.
if (matchAssemblyPath == null)
{
return null;
}
// If the target assembly is already loaded, return the existing assembly instance.
Assembly loadedAssembly = AppDomain.CurrentDomain.GetAssemblies().FirstOrDefault((x) => String.Equals(x.Location, matchAssemblyPath, StringComparison.OrdinalIgnoreCase));
if (loadedAssembly != null)
{
return loadedAssembly;
}
// Attempt to load the target assembly
try
{
return LoadAssembly(matchAssemblyPath);
}
catch (Exception ex)
{
// Log an error
}
return null;
}
The first part of that event handler deals with satellite resource assemblies, then the search behaviour I use for regular assemblies follows that. This should be enough to help anyone get a system like this working from scratch.

Ok If you want "detach" yoursefl from standart Localization resource binding, and want to have freedom to load an assembly from any location, one of the options is to
a) implement an interface to interact with translations within that assembly
b) use Assembly.Load function to load .NET assembly you want from location you want

Programmatically get the version number of a DLL

Is it possible to get the version number programmatically from any .NET DLL?
If yes, how?

This works if the dll is .net or Win32. Reflection methods only work if the dll is .net. Also, if you use reflection, you have the overhead of loading the whole dll into memory. The below method does not load the assembly into memory.
// Get the file version.
FileVersionInfo myFileVersionInfo = FileVersionInfo.GetVersionInfo(#"C:\MyAssembly.dll");
// Print the file name and version number.
Console.WriteLine("File: " + myFileVersionInfo.FileDescription + '\n' +
"Version number: " + myFileVersionInfo.FileVersion);
From: http://msdn.microsoft.com/en-us/library/system.diagnostics.fileversioninfo.fileversion.aspx
original source

Assembly assembly = Assembly.LoadFrom("MyAssembly.dll");
Version ver = assembly.GetName().Version;
Important:
It should be noted that this is not the best answer to the original question. Don't forget to read more on this page.

First of all, there are two possible 'versions' that you might be interested in:
Windows filesystem file version, applicable to all executable files
Assembly build version, which is embedded in a .NET assembly by the compiler (obviously only applicable to .NET assembly dll and exe files)
In the former case, you should use Ben Anderson's answer; in the latter case, use AssemblyName.GetAssemblyName(#"c:\path\to\file.dll").Version, or Tataro's answer, in case the assembly is referenced by your code.
Note that you can ignore all the answers that use .Load()/.LoadFrom() methods, since these actually load the assembly in the current AppDomain - which is analogous to cutting down a tree to see how old it is.

Here's a nice way using a bit of reflection to get a version of a DLL containing a particular class:
var ver = System.Reflection.Assembly.GetAssembly(typeof(!Class!)).GetName().Version;
Just replace !Class! with the name of a class which is defined in the DLL you wish to get the version of.
This is my preferred method because if I move the DLLs around for different deploys I don't have to change the filepath.

To get it for the assembly that was started (winform, console app, etc...)
using System.Reflection;
...
Assembly.GetEntryAssembly().GetName().Version

Kris, your version works great when needing to load the assembly from the actual DLL file (and if the DLL is there!), however, one will get a much unwanted error if the DLL is EMBEDDED (i.e., not a file but an embedded DLL).
The other thing is, if one uses a versioning scheme with something like "1.2012.0508.0101", when one gets the version string you'll actually get "1.2012.518.101"; note the missing zeros.
So, here's a few extra functions to get the version of a DLL (embedded or from the DLL file):
public static System.Reflection.Assembly GetAssembly(string pAssemblyName)
{
System.Reflection.Assembly tMyAssembly = null;
if (string.IsNullOrEmpty(pAssemblyName)) { return tMyAssembly; }
tMyAssembly = GetAssemblyEmbedded(pAssemblyName);
if (tMyAssembly == null) { GetAssemblyDLL(pAssemblyName); }
return tMyAssembly;
}//System.Reflection.Assembly GetAssemblyEmbedded(string pAssemblyDisplayName)
public static System.Reflection.Assembly GetAssemblyEmbedded(string pAssemblyDisplayName)
{
System.Reflection.Assembly tMyAssembly = null;
if(string.IsNullOrEmpty(pAssemblyDisplayName)) { return tMyAssembly; }
try //try #a
{
tMyAssembly = System.Reflection.Assembly.Load(pAssemblyDisplayName);
}// try #a
catch (Exception ex)
{
string m = ex.Message;
}// try #a
return tMyAssembly;
}//System.Reflection.Assembly GetAssemblyEmbedded(string pAssemblyDisplayName)
public static System.Reflection.Assembly GetAssemblyDLL(string pAssemblyNameDLL)
{
System.Reflection.Assembly tMyAssembly = null;
if (string.IsNullOrEmpty(pAssemblyNameDLL)) { return tMyAssembly; }
try //try #a
{
if (!pAssemblyNameDLL.ToLower().EndsWith(".dll")) { pAssemblyNameDLL += ".dll"; }
tMyAssembly = System.Reflection.Assembly.LoadFrom(pAssemblyNameDLL);
}// try #a
catch (Exception ex)
{
string m = ex.Message;
}// try #a
return tMyAssembly;
}//System.Reflection.Assembly GetAssemblyFile(string pAssemblyNameDLL)
public static string GetVersionStringFromAssembly(string pAssemblyDisplayName)
{
string tVersion = "Unknown";
System.Reflection.Assembly tMyAssembly = null;
tMyAssembly = GetAssembly(pAssemblyDisplayName);
if (tMyAssembly == null) { return tVersion; }
tVersion = GetVersionString(tMyAssembly.GetName().Version.ToString());
return tVersion;
}//string GetVersionStringFromAssemblyEmbedded(string pAssemblyDisplayName)
public static string GetVersionString(Version pVersion)
{
string tVersion = "Unknown";
if (pVersion == null) { return tVersion; }
tVersion = GetVersionString(pVersion.ToString());
return tVersion;
}//string GetVersionString(Version pVersion)
public static string GetVersionString(string pVersionString)
{
string tVersion = "Unknown";
string[] aVersion;
if (string.IsNullOrEmpty(pVersionString)) { return tVersion; }
aVersion = pVersionString.Split('.');
if (aVersion.Length > 0) { tVersion = aVersion[0]; }
if (aVersion.Length > 1) { tVersion += "." + aVersion[1]; }
if (aVersion.Length > 2) { tVersion += "." + aVersion[2].PadLeft(4, '0'); }
if (aVersion.Length > 3) { tVersion += "." + aVersion[3].PadLeft(4, '0'); }
return tVersion;
}//string GetVersionString(Version pVersion)
public static string GetVersionStringFromAssemblyEmbedded(string pAssemblyDisplayName)
{
string tVersion = "Unknown";
System.Reflection.Assembly tMyAssembly = null;
tMyAssembly = GetAssemblyEmbedded(pAssemblyDisplayName);
if (tMyAssembly == null) { return tVersion; }
tVersion = GetVersionString(tMyAssembly.GetName().Version.ToString());
return tVersion;
}//string GetVersionStringFromAssemblyEmbedded(string pAssemblyDisplayName)
public static string GetVersionStringFromAssemblyDLL(string pAssemblyDisplayName)
{
string tVersion = "Unknown";
System.Reflection.Assembly tMyAssembly = null;
tMyAssembly = GetAssemblyDLL(pAssemblyDisplayName);
if (tMyAssembly == null) { return tVersion; }
tVersion = GetVersionString(tMyAssembly.GetName().Version.ToString());
return tVersion;
}//string GetVersionStringFromAssemblyEmbedded(string pAssemblyDisplayName)

Answer by #Ben proved to be useful for me. But I needed to check the product version as it was the main increment happening in my software and followed semantic versioning.
myFileVersionInfo.ProductVersion
This method met my expectations
Update: Instead of explicitly mentioning dll path in program (as needed in production version), we can get product version using Assembly.
Assembly assembly = Assembly.GetExecutingAssembly();
FileVersionInfo fileVersionInfo =FileVersionInfo.GetVersionInfo(assembly.Location);
string ProdVersion= fileVersionInfo.ProductVersion;

var versionAttrib = new AssemblyName(Assembly.GetExecutingAssembly().FullName);

You can use System.Reflection.Assembly.Load*() methods and then grab their AssemblyInfo.

While the original question may not have been specific to a web service, here is a complete testWebService you can add to display a web service non-cached response plus the file version. We use file version instead of assembly version because we want to know a version, but with all assembly versions 1.0.0.0, the web site can be easily patched (signing and demand link still active!). Replace #Class# with the name of the web api controller this service is embedded in. It's good for a go/nogo on a web service plus a quick version check.
[Route("api/testWebService")]
[AllowAnonymous]
[HttpGet]
public HttpResponseMessage TestWebService()
{
HttpResponseMessage responseMessage = Request.CreateResponse(HttpStatusCode.OK);
string loc = Assembly.GetAssembly(typeof(#Class#)).Location;
FileVersionInfo versionInfo = FileVersionInfo.GetVersionInfo(loc);
responseMessage.Content = new StringContent($"<h2>The XXXXX web service GET test succeeded.</h2>{DateTime.Now}<br/><br/>File Version: {versionInfo.FileVersion}");
responseMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("text/html");
Request.RegisterForDispose(responseMessage);
return responseMessage;
}
I found it also necessary to add the following to web.config under configuration to make it truly anonymous
<location path="api/testwebservice">
<system.web>
<authorization>
<allow users="*" />
</authorization>
</system.web>
</location>