How to check the version of an assembly (dll)?

Question

I have c# application and when I made a change, I am getting the error message:

An unhandled exception of type 'System.TypeLoadException' occurred in WindowsFormsApplication1.exe

Additional information: Could not load type
'TradeIdeas.TIProData.OddsMakerColumnConfiguration' from assembly 'TIProData, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null’.

This message says the version number of dll (TIProData) is 1.0.0.0. I think there is a later version available. How can I tell the version number of a dll on my machine?

RIght click on the DLL go to Properties > Details. Version 1.0.0.0 Looks like its a development version of the DLL — Alex Anderson, Apr 21 '15 at 12:22
That is the file version, not the assembly version @AlexAnderson — Patrick Hofman, Apr 21 '15 at 12:22
Open csproj file in text editor and find that dll reference, you can change version there, seems there is 1.0.0.0 hard coded — sll, Apr 21 '15 at 12:23
See powershell commands in https://stackoverflow.com/questions/3267009/get-file-version-and-assembly-version-of-dll-files-in-the-current-directory-and — Michael Freidgeim, May 31 '22 at 21:01
Does this answer your question? [How can I get the assembly file version](https://stackoverflow.com/questions/909555/how-can-i-get-the-assembly-file-version) — Michael Freidgeim, May 31 '22 at 21:06

Patrick Hofman · Accepted Answer · 2015-04-21T13:03:18.390

76

You can use Reflector, ILDASM or ILSpy to get the assembly version.

You usually can find ILDASM in C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A\bin\NETFX 4.5.1 Tools\ildasm.exe (where v8.1A is the version of the Windows SDK installed).

ILDASM:

ildasm

Reflector:

reflector

edited Apr 21 '15 at 13:03

answered Apr 21 '15 at 12:24

Patrick Hofman

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Or [Jetbrains dotPeek](https://www.jetbrains.com/decompiler/), which is also free. – NightOwl888 Jun 19 '19 at 20:46
3

Btw it is absurd how hard Microsoft makes something this basic – A X May 02 '21 at 21:55
Why is it different from the dll version from windows explorer file details? – Fantastory Apr 20 '23 at 09:12

score 8 · Answer 2 · answered Apr 21 '15 at 13:09

8

There is a couple of ways to do it:

If you reference the dll in Visual Studio right click it (in ProjectName/References folder) and select "Properties" you have "Version" and "Runtime Version" there.
In File Explorer when you right click the dll file and select properties there is a "File Version" and "Product Version" there.

Alternatively, investigate it in code:

Assembly assembly = Assembly.LoadFrom("TestAssembly.dll");
Version ver = assembly.GetName().Version;

answered Apr 21 '15 at 13:09

PiotrWolkowski

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Caution - the "FileVersion" shown in the properties tab is NOT the same thing as AssemblyVersion which is the id used for binding redirects or assembly loading. – NeilMacMullen Apr 22 '21 at 08:27
1

@NeilMacMullen Yes! This has bitten me a few times. A workaround I found is to open the DLL with 7-zip and read the Assembly Version from .rsrc/version.txt . Baffles me why this isn't displayed in the File Properties dialog along with the rest of it. – JuSTMOnIcAjUSTmONiCAJusTMoNICa May 31 '22 at 16:49

score 3 · Answer 3 · edited Aug 22 '23 at 14:15

3

If you know Class, that belongs to assembly, you can use GetTypeInfo

var runtimeVersion = typeof(MyClass)
.GetTypeInfo()
.Assembly
.GetCustomAttribute<AssemblyFileVersionAttribute>();

var version = runtimeVersion.Version;

The example is for .Net Core from https://developers.de/blogs/damir_dobric/archive/2017/06/27/how-to-deal-with-assembly-version-in-net-core.aspx

edited Aug 22 '23 at 14:15

meJustAndrew

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answered Oct 24 '18 at 08:52

Michael Freidgeim

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score 2 · Answer 4 · edited Apr 21 '15 at 12:48

2

You can use AssemblyName.GetAssemblyName(string path) from a little util app.

Further details here on MSDN.

edited Apr 21 '15 at 12:48

Patrick Hofman

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answered Apr 21 '15 at 12:24

James Lucas

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score 2 · Answer 5 · answered Feb 17 '23 at 14:28

2

From Powershell (PSCore): $assembly = [System.Reflection.Assembly]::LoadFrom("$pwd\System.Memory.dll") Besides $assembly.FullName you can pick up any other prop from the object.

answered Feb 17 '23 at 14:28

dbardakov

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This approach silently gives the wrong answer if a DLL with the same name but in a different folder happens to be loaded already by the PowerShell process. In that case, it gives the assembly version of the already loaded DLL. – Edward Brey May 12 '23 at 17:33

How to check the version of an assembly (dll)?

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