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CefSharp.offscreen in LinqPad

LinqPad is my goto REPL and there isn't much I throw at it that it cant handle.
However I cannot for the life of me get CefSharp (specifically OffScreen) to run.
I'm constantly met with either of the below errors
Could not load file or assembly 'CefSharp.Core.Runtime, Version=95.7.141.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138' or one of its dependencies. The system cannot find the file specified.
BadImageFormatException: Could not load file or assembly 'CefSharp.Core.Runtime, Version=95.7.141.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138'. An attempt was made to load a program with an incorrect format.
I have tried
LP5/6 32 and 64 bit
Adding Cefsharp via nuget
Referencing .dll's manually from the file system
Referencing x86 or x64 .dll's
Copying .dll's into assembly search paths
Adding nuget paths to Environment path
And what seems like every combination of the above.
I don't understand the assembly resolution process that Visual Studio uses with the nuget package, but whatever it does I would like to at least simulate in Linqpad so I can avoid the VS ceremony when testing something simple.
I assume that manually referencing the correct .dll's and maybe setting a path somewhere should be sufficient, but I'm ideas=>EOF.
Can CefSharp be run outside of VS / MSBuild ?

It doesn't work because of the shadow-copying that LinqPad is using. Here is a hack to make your problem go away (spoiler alert: not really, read on):
For LinqPad v5
Copy all CefSharp libraries to a separate folder (don't forget cef.redist).
In LinqPad Preferences dialog (Advanced/Execution), set Do not shadow assembly references to True, restart LinqPad.
Write your code in the LinqPad query.
Reference CefSharp libraries from the folder you've set up on step 1.
Run the query.
For previous LinqPad (earlier than v5)
Write your code in the LinqPad query.
Reference CefSharp libraries, so you get an exception from your question
Find a LinqPad working directory (usually something like C:\Users\<user>\AppData\Local\Temp\LINQPad5\_yyigmhzg).
Copy all CefSharp libraries to this folder (don't forget cef.redist).
In LinqPad, click Ctrl + Shift + F5; this will reset the query state.
Rerun the query.
Now all the referenced libraries should load. But you will likely face more problems after that.
I couldn't make CefSharp.MinimalExample work. LinqPad kept crashing for me with the cryptic message Query ended because an uncatchable exception was thrown and a crashdump.
Although I am not sure if you will make CefSharp work as intended under LinqPad, maybe this can get you a bit further.

Found the answer with motivation from #Sasha's post and #amaitland's note about BadImageFormatException's being more than just incorrect architectures.
The below is all in reference to LP6 and CefSharp.Offscreen.NetCore. I have not pushed the efforts into LP5 but the process should be similar.
After some trial and error I narrowed down all of the necessary dependencies and worked out why CefSharp would not run in LinqPad.
Here are the steps to make it run -
Add CefSharp.Offscreen.NetCore package as normal to query
Enable Copy all NuGet assemblies into a single local folder (F4->Advanced)
Add the OnInit() and queryPath code as below to the query
Ensure the BrowserSubprocessPath is set before Initializing Cef
Here is the code.
async Task Main()
{
var are = new AutoResetEvent(false);//my technique for waiting for the browser
var sett = new CefSettings();
sett.BrowserSubprocessPath = this.queryPath + #"\CefSharp.BrowserSubprocess.exe"; //CefSharp will complain it cant find it
if (!Cef.IsInitialized)
Cef.Initialize(sett);
var browser = new ChromiumWebBrowser("http://www.google.com");
browser.LoadingStateChanged += (sender, args) => { if (!args.IsLoading) are.Set(); };
are.WaitOne();
await browser.WaitForInitialLoadAsync();
var html = await browser.GetBrowser().MainFrame.GetSourceAsync();
html.Dump("winner winner chicken dinner");
}
//this is the location of the queries shaddow folder
string queryPath = Path.GetDirectoryName(typeof(CefSettings).Assembly.Location);
void OnInit() // Executes when the query process first loads
{
if (!Directory.Exists(queryPath + #"\locales")) //subdirectory of cef.redist
{
var nugetPath = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
var sources = new[] {
/*paths here are hardcoded version dependant. Can get cefsharp.common.netcore version
from Util.CurrentQuery.NuGetReferences, but cef.redist not available via that method. */
#"cef.redist.x64\95.7.14\CEF", //contans all the Cef dependencies needed
#"cefsharp.common.netcore\95.7.141\runtimes\win-x64\lib\netcoreapp3.1", //mainly for ijwhost.dll
#"cefsharp.common.netcore\95.7.141\runtimes\win-x64\native"}; //contains BrowserSubprocess & friends
var dst = new DirectoryInfo(queryPath);
foreach (var path in sources)
{
var src = new DirectoryInfo($#"{nugetPath}\.nuget\packages\{path}");
CopyFilesRecursively(src, dst);
}
}
}
//curtesy of https://stackoverflow.com/a/58779/2738249 with slight mod
public static void CopyFilesRecursively(DirectoryInfo source, DirectoryInfo target)
{
foreach (DirectoryInfo dir in source.GetDirectories())
CopyFilesRecursively(dir, target.CreateSubdirectory(dir.Name));
foreach (FileInfo file in source.GetFiles())
{
var dst = Path.Combine(target.FullName, file.Name);
if (!File.Exists(dst))
file.CopyTo(dst);
}
}
The why for those interested -
CefSharp needs every dependency to be in the same directory so they can be resolved at runtime, but Linqpad only copies a few key dll's from the NuGet package. None of the cef.redist files, ijwhost.dll or BrowserSubprocess.exe et al. come across. Dependencies are scattered between NuGet packages and trying to resolve them directly from the .nuget cache just does not work. So all these need to be brought in manually to the running query shadow path.
I did initially copy all files into the Assembly.GetExecutingAssembly().Location path, but this approach requires adding the assembly directory to the "path" environment variable.
Internally Linqpad seems to have the shadow path set, so copying the dependencies to the shadow folder skips the need to set the environment variable.

DirectoryInfo throwing a System.OverflowException

When I construct a new DirectoryInfo using a network path like this:
using Delimon.Win32.IO;
DirectoryInfo di = new DirectoryInfo(#"\\a\path\to\a\place\you\are\not\allowed\to\know")
I know the path is correct since it opens in my browser when I copy paste. But I am getting an error:
"System.OverflowException: Arithmetic operation resulted in an overflow."
This is all the call stack info I can give.
System.OverflowException: Arithmetic operation resulted in an overflow.
at Delimon.Win32.IO.Helpers.GetFileInformation(String path)
at Delimon.Win32.IO.FileSystemInfo.Refresh()
at Delimon.Win32.IO.DirectoryInfo..ctor(String dir)
The path is 67 characters long. So its not a long path.
I can't find any documentation on System.OverflowException resulting from the construction of DirectoryInfo objects.
Any help?

I was getting this exact error just now
System.OverflowException: 'Arithmetic operation resulted in an overflow.'
and managed to isolate the cause.
The following line was giving the error:
string[] files = Delimon.Win32.IO.Directory.GetFiles(#"d:\temp");
This line is from an old app that I'm rewriting. Knowing that it works in the old version, but not in the new version, I've removed everything and everything in the new version and was left with an empty form. I still got the error.
Then I created a new empty project and tried the code in it, and it worked. So even though I removed everything in my new app, I still get the error. This suggests there's something wrong with the settings. So I started comparing project files.
In the *.csproj file, there was this line:
<Prefer32Bit>false</Prefer32Bit>
and it was not in the old app nor in the new project.
It seems that when a new project is created, "Prefer 32-bit" (Project -> Properties -> Build -> General) is checked by default, but in my new app, this was not checked. I don't remember unchecking it myself, so I don't know how it got unchecked. Once I checked it, I no longer get the error.

I was using Delimon.Win32.IO.DirectoryInfo which is apparently an old, un-maintained code base. I should have been using System.IO.DirectoryInfo

.NET executables do not work after overwritten with new versions

I faced very strange behaviour - after I overwrite .NET exectables with new versions from network drive it cannot start.
When try to start from Windows Explorer it shows me following error:
[Window Title]
C:\Programs\zzz\clients.net\zzzNet.exe
[Content]
C:\Programs\zzz\clients.net\zzzNet.exe
The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more detail.
I tried to execute following commands:
SxsTrace Trace -logfile:SxsTrace.etl
SxStrace Parse -logfile:SxSTrace.etl -outfile:SxSTrace.txt
And got following result:
=================
Begin Activation Context Generation.
Input Parameter:
Flags = 0
ProcessorArchitecture = AMD64
CultureFallBacks = en-US;en;ru-RU;ru
ManifestPath = C:\Programs\zzz\clients.net\zzzNet.exe
AssemblyDirectory = C:\Programs\zzz\clients.net\
Application Config File = C:\Programs\zzz\clients.net\zzzNet.exe.Config
-----------------
INFO: Parsing Application Config File C:\Programs\zzz\clients.net\zzzNet.exe.Config.
INFO: Parsing Manifest File C:\Programs\zzz\clients.net\zzzNet.exe.
INFO: Manifest Definition Identity is (null).
ERROR: Line 0: XML Syntax error.
ERROR: Activation Context generation failed.
End Activation Context Generation.
It is quite simple .NET application (1 exe + 8 dll files). It was built for .NET 3.5 Client Profile.
I not defined any special "manifest" there. Just clicked "New Windows Forms Project" in Visual Studio and developed it.
Also app.config does not contain anything special - only primitive standard settings - appSettings and userSettings sections.
On PC where I developed it all is perfectly works. Problems only began when I copy these binaries to this particular VM and try to start.
Also please note - these executables were not installed in GAC or such, I just copied them into a folder on VM and started. And when it was 1st time all was working fine.
So, the problem pattern is following:
Copy .NET execuatbles to new VM (it is Win 7 x64), run it, all is working fine. Close it.
Build new version of .NET execuatbles on host PC, copy new .NET execuatbles to VM (with files overwriting).
Try to start - got mentioned problem.
After some shaman-style actions (like OS reboot, etc) it begin to work but why that happened at all?!
Why replacing .NET executables with new versions is causing SUCH HUGE PROBLEMS?!
Also the BIG QUESTION - is there any special procedure to replace .NET executables to keep them working? Because it is a new app development, I do not want lost so much time on every new executables installation. :-\
Could you please help? Because it looks completely weird!
Thank you in adance.
PS. I checked all VS projects - all they have PlatformTarget=AnyCPU. Also in run-time I can see ProcessType=MSIL (I show this info in AboutBox for application). So, there is no mix of x86/x64 binaries.

It seems that was related to mapped network drive behavior.
When I copied new files from network drive folder it copied wrong files - a strange random mess of new files and older ones (which were there before I updated them on VM host).
The scenario to make it working:
on VM: delete all files in a folder on network drive
on VM host: copy new files into a folder which is mapped as network drive on VM
on VM: copy files into target folder
on VM: run application - it works now
Weird thing. I remember I have seen something similar with Windows Explorer on Windows 2008 behaviour when copying updated win32 binaries.

TuesPechkin unable to load DLL 'wkhtmltox.dll'

I've been using TuesPechkin for some time now and today I went to update the nuget package to the new version 2.0.0+ and noticed that Factory.Create() no longer resolved, so I went to read on the GitHub the changes made and noticed it now expects the path to the dll?
IConverter converter =
new ThreadSafeConverter(
new PdfToolset(
new StaticDeployment(DLL_FOLDER_PATH)));
For the past few hours I've tried almost all the paths I can think of, "\bin", "\app_data", "\app_start", etc and I can't seem to find or figure out what it wants for the path and what dll?
I can see the TuesPechkin dll in my bin folder and it was the first path I tried, but I got the following error:
Additional information: Unable to load DLL 'wkhtmltox.dll': The
specified module could not be found. (Exception from HRESULT:
0x8007007E)
Where is that dll and now can I get it as the library doesn't seem to contain it, I tried installing the TuesPechkin.Wkhtmltox.Win32 package but the dll still is nowhere to be found. Also I am using this in a asp.net website project so I assume that using the following should work for obtaining the path, right?
var path = HttpContext.Current.Server.MapPath(#"~\bin\TuesPechkin.dll");
Further information: https://github.com/tuespetre/TuesPechkin/issues/57

The Tuespechkin has a zip file as a resource in the Win32 and Win64 embedded packages for the 'wkhtmltox.dll' file.
What it does when you use the Win32 or Win64 Embedded package is unzips the file and places it in the directory that you specify.
I have been putting a copy of the wkhtmltox dll at the root portion of my web app directory and pointing the DLL_FOLDER_PATH to it using the server physical path of my web app to get to it.
According to the author, you must set the converter in a static field for best results.
I do that, but set the converter to null when I am finished using it, and that seems to work.
Tuespechkin is wrapper for the wmkhtmlox dll file.
The original file is written in C++ and so will not automatically be usable in C# or VB.NET or any of the other managed code domains.
The Tuespechkin.dll file DOES NOT contain a copy of 'wkhtmltox.dll'. You either have to use one of the other embedded deployment modules or install a copy of the 'wkhtmltox.dll' in your web app after downloading it from the internet. That is what I do, and it seems to work just fine.
I am using Team Foundation Server, and attempts to compile code after using the Tuespechkin routines will fail the first time because the 'wkhtmltox.dll' file gets locked, but all you have to do is simply retry your build and it will go through.
I had issues with the 32-bit routine not working in a 64-bit environment and the 64-bit environment not being testable on localhost. I went with the workaround I came up with after examining the source code for Tuespechkin and the Win32 and Win64 embedded deployment packages.
It works well as long as you specify a url for the input rather than raw html.
The older package didn't render css very well.
If you are using a print.aspx routine, you can create the url for it as an offset from your main url.
I don't have the source code I am using with me at this point to offset to your base url for your web application, but it is simply an offshoot of HttpRequest.
You have to use the physical path to find the .dll, but you can use a web path for the print routine.
I hope this answers your question a bit.

If you are getting this error -> Could not load file or assembly 'TuesPechkin.Wkhtmltox.Win64' or one of its dependencies. An attempt was made to load a program with an incorrect format.
In Visual Studio Go to -
Tools -> Options -> Projects and Solutions -> Web Projects -> Use the 64 bit version of IIS Express for web sites and projects.

I installed TuesPechkin.Wkhtmltox.Win64 Nuget package and used the following code in a singleton:
public class PechkinPDFConvertor : IPDFConvertor
{
IConverter converter =
new ThreadSafeConverter(
new RemotingToolset<PdfToolset>(
new Win64EmbeddedDeployment(
new TempFolderDeployment())));
public byte[] Convert(string html)
{
// return PechkinSync.Convert(new GlobalConfig(), html);
return converter.Convert(new HtmlToPdfDocument(html));
}
}
The web application then has to be run in x64 otherwise you will get an error about trying to load an x64 assembly in an x86 environment. Presumably you have to choose x64 or x86 at design time and use the corresponding nuget package, it would be nicer to choose this in the web.config.
EDIT: The above code failed on one server with the exact same message as yours - it was due to having not installed VC++ 2013. So the new code is running x86 as follows
try
{
string path = Path.Combine(Path.GetTempPath(), "MyApp_PDF_32");
Converter = new ThreadSafeConverter(
new RemotingToolset<PdfToolset>(
new Win32EmbeddedDeployment(
new StaticDeployment(path))));
}
catch (Exception e)
{
if (e.Message.StartsWith("Unable to load DLL 'wkhtmltox.dll'"))
{
throw new InvalidOperationException(
"Ensure the prerequisite C++ 2013 Redistributable is installed", e);
}
else
throw;
}

If you do not want run the installer for wkhtmltox just to get the dll, you can do the following:
As #Timothy suggests, if you use the embedded version of wkhtmltox.dll from TuesPechkin, it will unzip it and place it in a temp directory. I copied this dll and referenced it with the StaticDeployment option without any issues.
To find the exact location, I just used Process Monitor (procmon.exe). For me it was C:\Windows\Temp\-169958574\8\0.12.2.1\wkhtmltox.dll

In my case, I am deploying on a 64-bit VPS then I got this error. I have solved the problem by installing the wkhtmltopdf that I downloaded from http://wkhtmltopdf.org/downloads.html. I chose the 32-bit installer.

In my case, I have solved the problem by installing the Wkhtmltox for win32 at https://www.nuget.org/packages/TuesPechkin.Wkhtmltox.Win32/

This error: Unable to load DLL 'wkhtmltox.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E) is returned in two situations:
1- Deploy dependency not installed:
For solve this, you can install nuget package "TuesPechkin.Wkhtmltox.Win64" and use this code (for WebApplications running in IIS):
IConverter converter =
new ThreadSafeConverter(
new RemotingToolset<PdfToolset>(
new Win64EmbeddedDeployment(
new TempFolderDeployment())));
// Keep the converter somewhere static, or as a singleton instance!
// Do NOT run the above code more than once in the application lifecycle!
byte[] result = converter.Convert(document);
In runtime this code will copy the dependency "wkhtmltox.dll" in a temporary directory like: "C:\Windows\Temp\1402166677\8\0.12.2.1". It's possible to get the destination of file using:
var deployment = new Win64EmbeddedDeployment(new TempFolderDeployment());
Console.WriteLine(deployment.Path);
2- Microsoft Visual C++ 2013 Redistributable not installed:
As described here:
https://github.com/tuespetre/TuesPechkin/issues/65#issuecomment-71266114, the Visual C++ 2013 Runtime is required.
The solution from README is:
You must have Visual C++ 2013 runtime installed to use these packages. Otherwise, you will need to download the MingW build of wkhtmltopdf and its dependencies from their website and use that with the library. https://github.com/tuespetre/TuesPechkin#wkhtmltoxdll
or, you can install the Microsoft Visual C++ 2013 Redistributable:
choco install msvisualcplusplus2013-redist

Here is AnyCpu version, also support iis-base or winform application
using TuesPechkin.Wkhtmltox.AnyCPU;
...
var converter = PDFHelper.Factory.GetConverter();
var result = converter.Convert(This.Document);
Reference : https://github.com/tloy1966/TuesPechkin

Installing the Visual C++ Redistributable for Visual Studio 2013 resolved the error for me.
https://www.microsoft.com/en-us/download/details.aspx?id=40784

Tesseract 3 (OCR) - .NET Wrapper

http://code.google.com/p/tesseractdotnet/
I am having a problem getting Tesseract to work in my Visual Studio 2010 projects. I have tried console and winforms and both have the same outcome. I have come across a dll by someone else who claims to have it working in VS2010:
http://code.google.com/p/tesseractdotnet/issues/detail?id=1
I am adding a reference to the dll which can be found in the attached to post 64 from the website above. Every time I build my project I get an AccessViolationException saying that an attempt was made to read or write protected memory.
public void StartOCR()
{
const string language = "eng";
const string TessractData = #"C:\Users\Joe\Desktop\tessdata\";
using (TesseractProcessor processor = new TesseractProcessor())
{
using (Bitmap bmp = Bitmap.FromFile(fileName) as Bitmap)
{
if (processor.Init(TessractData, language, (int)eOcrEngineMode.OEM_DEFAULT))
{
string text = processor.Recognize(bmp);
}
}
}
}
The access violation exception always points to if (processor.Init(TessractData, language, (int)eOcrEngineMode.OEM_DEFAULT)). I've seen a few suggestions to make sure the solution platform is set to x86 in the configuration manager and that the tessdata folder location is finished with trailing slash, to no avail. Any ideas?

It appeared to be the contents of the tessdata folder that was causing the problem. Obtained the tessdata folder from the first link and all is now working.

I have just completed a project with tesseract engine 3. i think, there is a bug in the engine, that need to be rectified. What i Did to remove "AccessViolationError" is, add "\tessdata" to the real tessdata directory string. I don't know why, but the engine seems to be truncating the innermost directory in the Tessdata path.
Just made Full OCR package (Dlls+Tessdata(english)) that works with .net framework 4.

If somebody has the same problem and advice with trailing slash doesn't work, try... TWO ending slashes! Seriosly. It works for me.
if (processor.Init(#".\tessdata\\", "eng", (int)eOcrEngineMode.OEM_DEFAULT))

Seems your problem relates to stability issue mentioned here. On the official site there is a recommendation to use previous stable release 2.4.1. You can install it from nuget.org via the package manager command: Install-Package Tesseract -Version 2.4.1