Calling another EXE with C# on Windows fails on target machine - c#

I have created a Windows shell extension that provides a menu to users when they right-click in File Explorer. This then invokes a small dialogue App.
I'm a novice at software development so there is probably some schoolboy error I'm making but I just can't see it.
For testing purposes I am hard-coding the path to the EXE and ensuring it's present on the VM.
private void CallExteralAddLocation(string sFullPath)
{
string sEXE = Path.Combine(Application.StartupPath, "AddLocation.exe");
WriteLog(sEXE);
// during testing, hard-code this path
sEXE = "C:\\temp\\AddLocation.exe";
System.Diagnostics.Process.Start(sEXE, sFullPath);
}
private void WriteLog(string sText)
{
using (StreamWriter sr = new StreamWriter("C:\\Temp\\ShellExtLog.txt"))
{
sr.WriteLine(sText);
}
}
It works fine on my host machine but when running on a VM running Windows 10, which is where I am testing it, the dialogue App does not get invoked.
I have checked that I can invoke the AddLocation.exe from a command window on the VM and that works as expected. So it looks like it's just not getting called.
As it's a shell extension it's very difficult to debug. I tried using MessageBoxes and writing to the console but those wouldn't work, so I have added the WriteLog so that I have some idea of what it's doing.
This works on the host machine i.e. a log file is created and it shows the path to the EXE, but no log file is created on the VM.
NOTE: When testing on either machine, I'm installing afresh from the application's MSI. Also note that the host is running Windows 11 and the VM is running Windows 10.
So, why does the same code fail to either run the EXE or create a log file on the VM?

I eventually worked out that the problem was how C# handles strings.
If you read through my problem above you will see that, weirdly the same code worked fine on Windows 11 but not on Windows 10.
The problem was that I was letting the compiler interpret the path string. I had 'escaped' the slashes as shown here and it should have worked fine:
sEXE = "C:\\temp\\AddLocation.exe";
Changing it to the following resolved the problem so that it works on both now:
sEXE = #"C:\temp\AddLocation.exe";
Similarly, whereas it wouldn't create a log file on Win10, changing the path to the log file to the following fixed it:
using (StreamWriter sr = new StreamWriter(#"C:\Temp\ShellExtLog.txt"))

Related

Passing in Command Line Arguments to C# .NET app Without Using Manifest File Inside a UWP App

I have a UWP app that I am developing that launches another application, which in turn launches a bat file, which does certain tasks, in order to not block the UI thread, while having enough permissions to do the tasks. The EXE I'm trying to launch is a separate .NET framework app that is in the same SLN, but a different project, in an app package project. However, the second C# app that the UWP app is launching requires command line arguments that may as often as the user of the app decides, so they can't be hard-coded into the manifest file, and using the following command:
await FullTrustProcessLauncher.LaunchFullTrustProcessForCurrentAppAsync("ArgumentGroupName");
Is there an alternative to the above command that allows for parameters to be passed in, while changing the parameter value is available at every launch? I've googled for days without finding any topic on this apart from one comment on an SO post that I can't find that says that it can be done without using the app's manifest file. I am using the latest version of Visual Studio 2019 with the latest .NET Framework (4.8) and Windows SDK (Windows 2004-compatible). The second C# app runs using the .NET Framework and the main UWP app uses the Windows SDK.
Passing in Command Line Arguments to C# .NET app Without Using Manifest File Inside a UWP App
For your requirement, you could pass the launcher parameter with LocalSettings. Store the parameter in the UWP client and retrieve value from launcher, then call process start with retrieved paramete.
For example
UWP Client
private async void btnClick_Parameters(object sender, RoutedEventArgs e)
{
if (ApiInformation.IsApiContractPresent("Windows.ApplicationModel.FullTrustAppContract", 1, 0))
{
// store command line parameters in local settings
// so the Lancher can retrieve them and pass them on
ApplicationData.Current.LocalSettings.Values["parameters"] = "command parameter";
await FullTrustProcessLauncher.LaunchFullTrustProcessForCurrentAppAsync("Parameters");
}
}
Launcher
string parameters = ApplicationData.Current.LocalSettings.Values["parameters"] as string;
Process newProcess = Process.Start(rootPath + #"WPF\WPF.exe", parameters);
For more detail please refer stanfen's blog UWP with Desktop Extension – Part 2

Access Denied when running Windows Service

I have created a Windows Service using ASP.Net Core 3.x and C#. I started with the new Windows Service template when I built the project. When I run it from my development environment or from a console window it runs fine. When I install it as a Windows Service and attempt to start the service I get an
"Error 5: Access is denied." error.
I tried numerous things which I will outline below to eliminate the error but nothing seemed to work so I downloaded the sample app provided by Microsoft, at sample
Same result...when I run the sample app from within Visual Studio it runs fine, when running as a service I get the Access Denied error.
I am running all of this on my local machine, which I am an admin on.
I originally tried to run it using the default Local System account; got the Access Denied error.
I changed the Log On As to my domain account, the same one I use to log into my local machine which is an admin on this machine; got the same Access Denied error.
My account has the privilege set to run as a service.
The Event Viewer just shows the one message which says "Access Denied", no other messages are created.
I believe the Access Denied error is occurring before the C# code is even executed. What makes me believe this is that I added one line to the very top of the Program.Main.... File.WriteAllText("C:\\temp\\ws.log", $"Test of Worker Service # {DateTime.Now}. Content Root Path: {AppContext.BaseDirectory}");. My account has full access to the temp folder. This file gets created when I run the app from Visual Studio but it does not get created when I run the app as a service.
I have read numerous web sites, include this one and this one. No luck, everything I tried from these sites still produce the Access Denied error.
I have run out of ideas and am hoping someone here can provide me the answer. Thanks!
I found the solution and believe me I feel really stupid!!!
When I installed it as a service I only put the path in "binPath".
sc create WindowsService1 binPath="C:\temp".
Once I actually added the executable to the binPath parameter everything worked.
Changed it to sc create WindowsService1 binPath="C:\temp\WindowsService.exe" and it worked.
I know it is an Id10t error but Microsoft should really provide better messaging for the "sc" command. A message like "Cannot find file specified in the binPath parameter" would have been really helpful. Would have saved me about 6 hours of work.
Thanks everyone for reviewing and replying to this question.

Error when reading audio file?

I have the following function that I am attempting to use to determine the length of an MP3 file:
public static string GetMP3DurationBackup(string Filename)
{
string Duration = null;
WMPLib.WindowsMediaPlayer w = new WMPLib.WindowsMediaPlayer();
WMPLib.IWMPMedia m = w.newMedia(Filename);
if (m != null)
{
Duration = m.durationString;
}
w.close();
return Duration;
}
I have run into an issue where I get the following error:
Retrieving the COM class factory for component with CLSID
{6BF52A52-394A-11D3-B153-00C04F79FAA6} failed due to the following
error: 80040154..
when I call the above function from my web application (call below):
string test = MediaUtil.GetMP3DurationBackup(#"C:\Temp\Audio\bad.mp3");
But when I call it from a console application test harness I created (exact same call as above) it works fine. I have set the project that contains the function to target x86 in the Build properties, but that did not fix the issue.
Does anyone know why this would happen? Suggestions on where to start to debug this?
UPDATED FOR BOUNTY:
Ok, I've tried a number of things but I am still getting this error. Among other things I have tried the steps below which I felt were the most promising, but no dice:
Went into my registry and confirmed that the value at:
HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{6BF52A52-394A-11d3-B153-00C04F79FAA6}\InprocServer32
is refering to C:\WINDOWS\SysWOW64\wmp.dll
Opened command prompt,
navigated to C:\WINDOWS\SysWow64, ran: regsvr32.exe wmp.dll
I have created a console app test harness and I am able to reproduce the error if I run the test project in x64. If I switch it to x86 it works fine.
Does anyone have any idea of why the above would not resolve the issue? Suggestions on where to look next?
You say it doesn't work in x64, but you try to register the 32-bit version of wmp.dll (C:\Windows\SysWow64 contains 32-bit assemblies).
Try to register the x64 version of wmp.dll, which is located in C:\Windows\System32 on a 64-bit platform.
If you don't have this file then there probably is no 64bit Windows Media Player available for your platform. But there is a workaround:
Create a 32-bit console application that takes the mp3 filename as command line argument and outputs the duration to stdout using Console.WriteLine, then in the webapp, you call the console application and capture the output like in this example on MSDN
Give this lib a whirl. Its fast and has no special requirements for software to be installed on the machine.
http://naudio.codeplex.com/

C# .Net Service won't install on Win 7 64 bit

.Net 3.5
I've built into the service exe the ability for it to install itself using a -i feature. I have a custom installer class and am using a common technique on found online here. That installer class basically has it's own service and serviced process installer.
This code has worked well for a very long time. Finally ran into a Win 7 64 bit machine were it refuses to install.
Basically, the log shows it's installing the service and that succeeds. Then it tries to create an event log and that fails with
An exception occurred during the Install phase.
System.ComponentModel.Win32Exception: The specified service already
exists
I just got done having the OS completely reinstalled from scratch, first thing I did was try to install as a service, and it's the same error. Why is it thinking that event log is already there?
I've already read all the other posts and I've browsed my registry and there is nothing in there for my service or event log. I have full admin rights, when I try to open cmd as administrator, it doesn't even prompt me, so as far as I can tell, I am an admin (I can see that in my user profile).
I even added code to check to see if it found the EventLog using System.Diagnostics.EventLog.SourceExists which does report it found it, and so I added a call to System.Diagnostics.EventLog.DeleteEventSource but that doesn't help.
I even tried removing the EventLog installer from the ServiceInstaller, but then it starts failing for other reasons.
Any ideas?
Here is some sample code for an alternate installer I tried that I found here with the same results:
public partial class Service1Installer : Installer
{
public Service1Installer()
{
InitializeComponent();
ServiceProcessInstaller process = new ServiceProcessInstaller();
process.Account = ServiceAccount.LocalSystem;
ServiceInstaller serviceAdmin = new ServiceInstaller();
serviceAdmin.StartType = ServiceStartMode.Manual;
serviceAdmin.ServiceName = "Service1";
serviceAdmin.DisplayName = "Service1";
serviceAdmin.Description = "Service1";
Installers.Add(serviceAdmin);
Installers.Add(process );
}
}
uninstall your service
installutil /u yourproject.exe
restart your machine
http://msdn.microsoft.com/en-us/library/sd8zc8ha(v=vs.80).aspx
let me know if you still have a issue
Use installutil as #MicahArmantrout mentions, if the exe still resides on disk.
Otherwise, open a commandline as Administrator and execute: sc delete "my service name"
In the end, my problem was our internal installer. I commented it out and now just install the service from the command line and it now installs on 64 bit OS. Still don't know why it would work before on 32 bit.

File exists in Windows Explorer and notepad, but is not accessable in my program

Why does the following problem happen?
Scenario:
Make sure that IIS is installed
Execute "notepad
%WINDIR%\System32\inetsrv\config\applicationHost.config" using admin
account
Actual Result: the file is successfully opened in notepad
Execute the following code in admin account's context:
string filePath = #"%WINDIR%\System32\inetsrv\config\applicationHost.config";
Console.WriteLine(File.Exists(Environment.ExpandEnvironmentVariables(filePath)));
Actual Result: False
Expected Result: True
The problem is if you are running a 32-bit application on a 64-bit OS, the .Net framework automatically redirects the request from %WINDIR%\System32 to %WINDIR%\SysWOW64.
If you change your project to target 64-bit, this will solve your problem.
You can also resolve the problem by changing System32 to sysnative, but only if you leave the application as a 32-bit app:
string filePath = #"%WINDIR%\sysnative\inetsrv\config\applicationHost.config";
This might be due to file system redirection. AFAIK t happens either for 32/64 bit mismatch or in case of low-privilege (UAC) processes.
I know of now way of disabling that behavior using managed APIs. You need to use http://msdn.microsoft.com/en-us/library/windows/desktop/aa365743(v=vs.85).aspx and/or be a high privilege process.
If you change your project to target 64-bit, this is likely to solve your problem.
I can't reproduce your result. When I run this from an administrator command line prompt, I get exists = True.
string s = #"%WINDIR%/System32\inetsrv\config\applicationHost.config";
bool exists = File.Exists(Environment.ExpandEnvironmentVariables(s));
Console.WriteLine("exists = {0}", exists);
I'm running Windows Server 2008, 64-bit. .NET 4.0.

Categories

Resources