We Keep Coding

WPF programme not running correctly when run silently

I have written a small programme to perform a quick configuration on a client machine and it needs to be able to run with a GUI and silently from the command line. If I run it with the GUI then it works perfectly, if however I try to run it without then it just hangs.
I have traced the problem to this section of code:
string arg = "/C:\"setup.exe /qn ADD_OPINSIGHTS_WORKSPACE=1 OPINSIGHTS_WORKSPACE_ID=" + workSpaceID + " OPINSIGHTS_WORKSPACE_KEY=" + workSpaceKey + " AcceptEndUserLicenseAgreement=1\"";
log.Info(arg);
// Use ProcessStartInfo class
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.CreateNoWindow = false;
startInfo.UseShellExecute = false;
startInfo.FileName = "MMASetup-AMD64.exe";
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.Arguments = arg;
try
{
log.Info("try entered");
// Start the process with the info we specified.
// Call WaitForExit and then the using statement will close.
using (Process exeProcess = Process.Start(startInfo))
{
log.Info("Install started");
exeProcess.WaitForExit(30000);
log.Info("Install exit code: " + (exeProcess.ExitCode).ToString());
return (exeProcess.ExitCode).ToString();
}
}
catch (Exception e)
{
log.Error("MMA install threw an error: ", e);
return e.Message;
}
This method is in a seperate class to the GUI and silent code and is run in exactly the same way yet only reaches "Install started" when run silently. I know that the exe does finish so I have tried using the code in this solution but had the same problem:
ProcessStartInfo hanging on "WaitForExit"? Why?

I had the same Problem.
I made a startup class:
public partial class Startup {
// WPF App
private App _app;
[STAThread]
public static void Main(string[] args) {
try {
//Do what you need
//Check the args
//Start your setup silent
//start the WPF App if need it
this._app = new App();
this._app.InitializeComponent();
this._app.Run();
} catch (Exception ex) {
//Logging ex
}
}
After that you must change your Application Startup Object to the Startup Class.

I was running all of my work asynchronously and because I was not loading the GUI thread Windows was treating the application like a console app. Whereas a GUI thread would call other asynchronous methods and wait for them to finish a console application calls the methods and then closes because it has nothing left to do. The solution was to explicitly make the main thread wait like this:
public static void Main(string[] args)
{
try
{
Install().Wait();
}
catch (Exception ex)
{
}
}
private static async Task Install()
{}

NET VIEW behaves differently when used with Process.Start()

I use net.exe in my program to view all computers in a workgroup.
The code is as follows:
var net = new Process();
net.StartInfo.FileName = "net.exe";
net.StartInfo.CreateNoWindow = true;
net.StartInfo.Arguments = #"VIEW /DOMAIN:my-workgroup";
net.StartInfo.RedirectStandardOutput = true;
net.StartInfo.UseShellExecute = false;
net.StartInfo.RedirectStandardError = true;
net.Start();
The command works fine when I execute in a shell, but when I use the shown code, the command returns the device is not connected.
I also tried running the program as administrator, that makes no difference.
The domain name specified is actually a workgroup.
For net.exe running in the shell specifying a workgroup works fine.
Furthermore the code also works when I try a net view for a different domain. So there must be some difference in the environment when I run the command from the shell or with Process.Start().
What would be the reasons for the command to behave differently in the shell and with Process.Start()?

I don't know if it will solve what you're looking for, but this works for me;
You need to hook into the capture the output to bring it to the console
class Program
{
static void Main(string[] args)
{
var net = new Process()
{
StartInfo = new ProcessStartInfo("net.exe", #"view /domain:domain")
{
RedirectStandardOutput = true,
UseShellExecute = false,
},
};
net.OutputDataReceived += WriteToConsole;
net.ErrorDataReceived += WriteToConsole;
net.Start();
net.BeginOutputReadLine();
net.WaitForExit();
Console.ReadLine();
}
private static void WriteToConsole(object sender, DataReceivedEventArgs e)
{
Console.WriteLine(e.Data);
}
}

Queuing installations via Process.Start

I need to queue approximately 20 installations that are fully unattended (Using a C# winform application). Each installation has its own INI file (that is manually created) that contains the proper information on what arguments each installer requires for this procedure (read in before that program is executed). I'm running into issues with many application that when the setup.exe is executed the process closes immediately and launches its MSI (if applicable), causing my procedure to carry out with the next installation assuming that the first is complete. I have read similar problems snooping around the web, but no real solution on the issue... (some workarounds included using a batch file with the /Wait option which should have kept the setup.exe in memory until its MSI has completed). The setup.exe must be launched due to the fact that they contain bootstrappers.
What options do i have to resolve this dilemma?
Here is some sample code that demonstrates the procedure:
foreach (ListViewItem itm in this.lstSoftwares.Items)
{
try
{
if (itm.Checked)
{
lblStatus.Text = "Status: Installing " + current.ToString() + " of " + count.ToString();
string InstallPath = Path.Combine(Application.StartupPath, "Software",
itm.Text, itm.Tag.ToString());
string CommandLine = itm.SubItems[1].Text;
Process process = new Process();
process.StartInfo.FileName = InstallPath;
process.StartInfo.Arguments = CommandLine;
process.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
process.Start();
process.WaitForExit();
this.lstSoftwares.Items[i].SubItems[2].Text = "Complete";
current++;
}
Update
right after waitforexit() i'm using a loop that checks if the msiexec is running:
private bool MSIRunning()
{
try
{
using (var mutex = Mutex.OpenExisting(#"Global\_MSIExecute"))
{
return true;
}
}
catch (Exception)
{
return false;
}
}
this is a hack in my opionion, but doing the trick so far...

Querying the MSI Mutex after process.start in a loop (check if Mutex is running every 3 seconds, if not return and proceed with next install) seemed to solve the problem (Noted above).

Already answered, but I have a slightly more robust implementation of the MSI mutex check:
public bool IsMsiExecFree(TimeSpan maxWaitTime)
{
_logger.Info(#"Waiting up to {0}s for Global\_MSIExecute mutex to become free...", maxWaitTime.TotalSeconds);
// The _MSIExecute mutex is used by the MSI installer service to serialize installations
// and prevent multiple MSI based installations happening at the same time.
// For more info: http://msdn.microsoft.com/en-us/library/aa372909(VS.85).aspx
const string installerServiceMutexName = "Global\\_MSIExecute";
Mutex msiExecuteMutex = null;
var isMsiExecFree = false;
try
{
msiExecuteMutex = Mutex.OpenExisting(installerServiceMutexName,
MutexRights.Synchronize);
isMsiExecFree = msiExecuteMutex.WaitOne(maxWaitTime, false);
}
catch (WaitHandleCannotBeOpenedException)
{
// Mutex doesn't exist, do nothing
isMsiExecFree = true;
}
catch (ObjectDisposedException)
{
// Mutex was disposed between opening it and attempting to wait on it, do nothing
isMsiExecFree = true;
}
finally
{
if (msiExecuteMutex != null && isMsiExecFree)
msiExecuteMutex.ReleaseMutex();
}
_logger.Info(#"Global\_MSIExecute mutex is free, or {0}s has elapsed.", maxWaitTime.TotalSeconds);
return isMsiExecFree;
}

Restart an application by itself

I want to build my application with the function to restart itself. I found on codeproject
ProcessStartInfo Info=new ProcessStartInfo();
Info.Arguments="/C choice /C Y /N /D Y /T 3 & Del "+
Application.ExecutablePath;
Info.WindowStyle=ProcessWindowStyle.Hidden;
Info.CreateNoWindow=true;
Info.FileName="cmd.exe";
Process.Start(Info);
Application.Exit();
This does not work at all...
And the other problem is, how to start it again like this?
Maybe there are also arguments to start applications.
Edit:
http://www.codeproject.com/script/Articles/ArticleVersion.aspx?aid=31454&av=58703

I use similar code to the code you tried when restarting apps. I send a timed cmd command to restart the app for me like this:
ProcessStartInfo Info = new ProcessStartInfo();
Info.Arguments = "/C ping 127.0.0.1 -n 2 && \"" + Application.ExecutablePath + "\"";
Info.WindowStyle = ProcessWindowStyle.Hidden;
Info.CreateNoWindow = true;
Info.FileName = "cmd.exe";
Process.Start(Info);
Application.Exit();
The command is sent to the OS, the ping pauses the script for 2-3 seconds, by which time the application has exited from Application.Exit(), then the next command after the ping starts it again.
Note: The \" puts quotes around the path, incase it has spaces, which cmd can't process without quotes.
Hope this helps!

Why not use
Application.Restart();
??
More on Restart

Why not just the following?
Process.Start(Application.ExecutablePath);
Application.Exit();
If you want to be sure the app does not run twice either use Environment.Exit(-1) which kills the process instantaneously (not really the nice way) or something like starting a second app, which checks for the process of the main app and starts it again as soon as the process is gone.

You have the initial application A, you want to restart.
So, When you want to kill A, a little application B is started, B kill A, then B start A, and kill B.
To start a process:
Process.Start("A.exe");
To kill a process, is something like this
Process[] procs = Process.GetProcessesByName("B");
foreach (Process proc in procs)
proc.Kill();

A lot of people are suggesting to use Application.Restart. In reality, this function rarely performs as expected. I have never had it shut down the application I am calling it from. I have always had to close the application through other methods such as closing the main form.
You have two ways of handling this. You either have an external program that closes the calling process and starts a new one,
or,
you have the start of your new software kill other instances of same application if an argument is passed as restart.
private void Application_Startup(object sender, StartupEventArgs e)
{
try
{
if (e.Args.Length > 0)
{
foreach (string arg in e.Args)
{
if (arg == "-restart")
{
// WaitForConnection.exe
foreach (Process p in Process.GetProcesses())
{
// In case we get Access Denied
try
{
if (p.MainModule.FileName.ToLower().EndsWith("yourapp.exe"))
{
p.Kill();
p.WaitForExit();
break;
}
}
catch
{ }
}
}
}
}
}
catch
{
}
}

Winforms has the Application.Restart() method, which does just that. If you're using WPF, you can simply add a reference to System.Windows.Forms and call it.

Another way of doing this which feels a little cleaner than these solutions is to run a batch file which includes a specific delay to wait for the current application to terminate. This has the added benefit of preventing the two application instances from being open at the same time.
Example windows batch file ("restart.bat"):
sleep 5
start "" "C:\Dev\MyApplication.exe"
In the application, add this code:
// Launch the restart batch file
Process.Start(#"C:\Dev\restart.bat");
// Close the current application (for WPF case)
Application.Current.MainWindow.Close();
// Close the current application (for WinForms case)
Application.Exit();

My solution:
private static bool _exiting;
private static readonly object SynchObj = new object();
public static void ApplicationRestart(params string[] commandLine)
{
lock (SynchObj)
{
if (Assembly.GetEntryAssembly() == null)
{
throw new NotSupportedException("RestartNotSupported");
}
if (_exiting)
{
return;
}
_exiting = true;
if (Environment.OSVersion.Version.Major < 6)
{
return;
}
bool cancelExit = true;
try
{
List<Form> openForms = Application.OpenForms.OfType<Form>().ToList();
for (int i = openForms.Count - 1; i >= 0; i--)
{
Form f = openForms[i];
if (f.InvokeRequired)
{
f.Invoke(new MethodInvoker(() =>
{
f.FormClosing += (sender, args) => cancelExit = args.Cancel;
f.Close();
}));
}
else
{
f.FormClosing += (sender, args) => cancelExit = args.Cancel;
f.Close();
}
if (cancelExit) break;
}
if (cancelExit) return;
Process.Start(new ProcessStartInfo
{
UseShellExecute = true,
WorkingDirectory = Environment.CurrentDirectory,
FileName = Application.ExecutablePath,
Arguments = commandLine.Length > 0 ? string.Join(" ", commandLine) : string.Empty
});
Application.Exit();
}
finally
{
_exiting = false;
}
}
}

This worked for me:
Process.Start(Process.GetCurrentProcess().MainModule.FileName);
Application.Current.Shutdown();
Some of the other answers have neat things like waiting for a ping to give the initial application time to wind down, but if you just need something simple, this is nice.

For .Net application solution looks like this:
System.Web.HttpRuntime.UnloadAppDomain()
I used this to restart my web application after changing AppSettings in myconfig file.
System.Configuration.Configuration configuration = WebConfigurationManager.OpenWebConfiguration("~");
configuration.AppSettings.Settings["SiteMode"].Value = model.SiteMode.ToString();
configuration.Save();

Hanging process when run with .NET Process.Start -- what's wrong?

I wrote a quick and dirty wrapper around svn.exe to retrieve some content and do something with it, but for certain inputs it occasionally and reproducibly hangs and won't finish. For example, one call is to svn list:
svn list "http://myserver:84/svn/Documents/Instruments/" --xml --no-auth-cache --username myuser --password mypassword
This command line runs fine when I just do it from a command shell, but it hangs in my app. My c# code to run this is:
string cmd = "svn.exe";
string arguments = "list \"http://myserver:84/svn/Documents/Instruments/\" --xml --no-auth-cache --username myuser --password mypassword";
int ms = 5000;
ProcessStartInfo psi = new ProcessStartInfo(cmd);
psi.Arguments = arguments;
psi.RedirectStandardOutput = true;
psi.WindowStyle = ProcessWindowStyle.Normal;
psi.UseShellExecute = false;
Process proc = Process.Start(psi);
StreamReader output = new StreamReader(proc.StandardOutput.BaseStream, Encoding.UTF8);
proc.WaitForExit(ms);
if (proc.HasExited)
{
return output.ReadToEnd();
}
This takes the full 5000 ms and never finishes. Extending the time doesn't help. In a separate command prompt, it runs instantly, so I'm pretty sure it's unrelated to an insufficient waiting time. For other inputs, however, this seems to work fine.
I also tried running a separate cmd.exe here (where exe is svn.exe and args is the original arg string), but the hang still occurred:
string cmd = "cmd";
string arguments = "/S /C \"" + exe + " " + args + "\"";
What could I be screwing up here, and how can I debug this external process stuff?
EDIT:
I'm just now getting around to addressing this. Mucho thanks to Jon Skeet for his suggestion, which indeed works great. I have another question about my method of handling this, though, since I'm a multi-threaded novice. I'd like suggestions on improving any glaring deficiencies or anything otherwise dumb. I ended up creating a small class that contains the stdout stream, a StringBuilder to hold the output, and a flag to tell when it's finished. Then I used ThreadPool.QueueUserWorkItem and passed in an instance of my class:
ProcessBufferHandler bufferHandler = new ProcessBufferHandler(proc.StandardOutput.BaseStream,
Encoding.UTF8);
ThreadPool.QueueUserWorkItem(ProcessStream, bufferHandler);
proc.WaitForExit(ms);
if (proc.HasExited)
{
bufferHandler.Stop();
return bufferHandler.ReadToEnd();
}
... and ...
private class ProcessBufferHandler
{
public Stream stream;
public StringBuilder sb;
public Encoding encoding;
public State state;
public enum State
{
Running,
Stopped
}
public ProcessBufferHandler(Stream stream, Encoding encoding)
{
this.stream = stream;
this.sb = new StringBuilder();
this.encoding = encoding;
state = State.Running;
}
public void ProcessBuffer()
{
sb.Append(new StreamReader(stream, encoding).ReadToEnd());
}
public string ReadToEnd()
{
return sb.ToString();
}
public void Stop()
{
state = State.Stopped;
}
}
This seems to work, but I'm doubtful that this is the best way. Is this reasonable? And what can I do to improve it?

One standard issue: the process could be waiting for you to read its output. Create a separate thread to read from its standard output while you're waiting for it to exit. It's a bit of a pain, but that may well be the problem.

Jon Skeet is right on the money!
If you don't mind polling after you launch your svn command try this:
Process command = new Process();
command.EnableRaisingEvents = false;
command.StartInfo.FileName = "svn.exe";
command.StartInfo.Arguments = "your svn arguments here";
command.StartInfo.UseShellExecute = false;
command.StartInfo.RedirectStandardOutput = true;
command.Start();
while (!command.StandardOutput.EndOfStream)
{
Console.WriteLine(command.StandardOutput.ReadLine());
}

I had to drop an exe on a client's machine and use Process.Start to launch it.
The calling application would hang - the issue ended up being their machine assuming the exe was dangerous and preventing other applications from starting it.
Right click the exe and go to properties. Hit "Unblock" toward the bottom next to the security warning.

Based on Jon Skeet's answer this is how I do it in modern day (2021) .NET 5
var process = Process.Start(processStartInfo);
var stdErr = process.StandardError;
var stdOut = process.StandardOutput;
var resultAwaiter = stdOut.ReadToEndAsync();
var errResultAwaiter = stdErr.ReadToEndAsync();
await process.WaitForExitAsync();
await Task.WhenAll(resultAwaiter, errResultAwaiter);
var result = resultAwaiter.Result;
var errResult = errResultAwaiter.Result;
Note that you can't await the standard output before the error, because the wait will hang in case the standard error buffer gets full first (same for trying it the other way around).
The only way is to start reading them asynchronously, wait for the process to exit, and then complete the await by using Task.WaitAll

I know this is an old post but maybe this will assist someone. I used this to execute some AWS (Amazon Web Services) CLI commands using .Net TPL tasks.
I did something like this in my command execution which is executed within a .Net TPL Task which is created within my WinForm background worker bgwRun_DoWork method which holding a loop with while(!bgwRun.CancellationPending). This contains the reading of the Standard Output from the Process via a new Thread using the .Net ThreadPool class.
private void bgwRun_DoWork(object sender, DoWorkEventArgs e)
{
while (!bgwRun.CancellationPending)
{
//build TPL Tasks
var tasks = new List<Task>();
//work to add tasks here
tasks.Add(new Task(()=>{
//build .Net ProcessInfo, Process and start Process here
ThreadPool.QueueUserWorkItem(state =>
{
while (!process.StandardOutput.EndOfStream)
{
var output = process.StandardOutput.ReadLine();
if (!string.IsNullOrEmpty(output))
{
bgwRun_ProgressChanged(this, new ProgressChangedEventArgs(0, new ExecutionInfo
{
Type = "ExecutionInfo",
Text = output,
Configuration = s3SyncConfiguration
}));
}
if (cancellationToken.GetValueOrDefault().IsCancellationRequested)
{
break;
}
}
});
});//work Task
//loop through and start tasks here and handle completed tasks
} //end while
}

I know my SVN repos can run slow sometimes, so maybe 5 seconds isn't long enough? Have you copied the string you are passing to the process from a break point so you are positive it's not prompting you for anything?