How to make an already existing process raise events, in C# [duplicate] - c#

Currently I have a program that starts another application and monitors that application to keep it running using this code:
System.Diagnostics.Process startProgram =
System.Diagnostics.Process.Start("program.exe", String.Format(Program.ConnectionArg));
startProgram.EnableRaisingEvents = true;
startProgram.SynchronizingObject = this;
startProgram.Exited += this.PrematureClose;
However my concern is what happens if my program is somehow killed. Is it possible to use the EnableRaisingEvents and startProgram.Exited when my program restarts?
I have a feeling I might need to ditch my code in favor of some sort of timer loop that checks if the process is still running.
EDIT 08-10-2016:
So I have tried the following code and VS based on Process Monitoring
What it's telling me:
cannot implicitly convert type 'System.Diagnostics.Process[]' to 'System.Diagnostics.Process'
System.Diagnostics.Process program_open_check =
System.Diagnostics.Process.GetProcessesByName("program");
program_open_check.EnableRaisingEvents = true;
program_open_check.SynchronizingObject = this;

Actually solved this and forgot to post.
So, the big issue was the process object was getting disposed since it was being used as part of a using block. The code below is the a solid way of doing this. Alternatively you could define a function directly instead of using a delegate.
Process[] processes_array = Process.GetProcessesByName("someprogram");
foreach (Process some_process in processes_array)
{
some_process.EnableRaisingEvents = true;
some_process.Exited += delegate (object sender, EventArgs args)
{
// Do work.
// DISPOSE PROCESS IF NOT USING IT AFTER THIS!!
};
}

Related

Why the Process Exited event raise automatic all the time?

In the top of Form1 i did:
private Process zipFileDirectoryProcess;
In the constructor i did:
zipFileDirectoryProcess = new Process();
zipFileDirectoryProcess.StartInfo.FileName = "explorer.exe";
zipFileDirectoryProcess.StartInfo.CreateNoWindow = true;
zipFileDirectoryProcess.EnableRaisingEvents = true;
zipFileDirectoryProcess.Exited += new EventHandler(zipFileDirectoryProcess_Exited);
Then i have a method i call it from a button click event:
private void Compress()
{
zipFileDirectoryProcess.StartInfo.Arguments = zipFileDirectoryProcess.StartInfo.Arguments = "/select," + Path.GetFullPath(t);
zipFileDirectoryProcess.Start();
zipFileDirectoryProcess.WaitForExit();
this.TopMost = true;
}
And then in the bottom the Exited event:
private void zipFileDirectoryProcess_Exited(object sender, EventArgs e)
{
this.BeginInvoke(new MethodInvoker(delegate()
{
this.TopMost = false;
}));
}
What i wanted to do is only when i close the process window after started it in the method only if closed the window/process then do the Exited event.
The problem is that once the process started after 2-3 seconds its jumping automatic to the Exited event.
How can i fix it ? Tried examples cant figure out.
Tried to add this line:
zipFileDirectoryProcess.WaitForExit();
But no effect.
zipFileDirectoryProcess.StartInfo.FileName = "explorer.exe";
Trying to start Windows Explorer again when it is already running, and it is always running, will have a disappointing outcome. It is a "heavy" process and it intentionally tries the minimize the number of running copies. Otherwise known as a "single-instance app". There are lots like that, the Microsoft Office programs are single instance apps for example.
So what really happens is that explorer.exe actually starts up, but sees that another instance is already running. And uses process interop to ask that first instance to do the job that you asked it to do. Since you didn't ask it to do anything, you just get another window, displayed by the first instance. The one that you started immediately quits, it doesn't have anything else to do.
So, yes, you'll see that the Exited event fires without you doing anything. Accurately telling you that the explorer.exe process you started did in fact quit. Easy to see in the Taskmgr.exe Processes tab btw. Waiting for that window to be closed is never going to work, it is displayed by the original instance of explorer.exe.
This will just not work the way you hope it will work. What you are actually trying to do is not quite obvious but can be guessed at. Creating a ZIP archive is not difficult, there are excellent libraries available for C# to get the job done, no point in asking another program to do it for you. DotNetZip and SharpZipLib are very popular. It got finally added to .NET as well in version 4.5, Microsoft finally getting over the lost Stacker lawsuit, about time. If you really, really want another program to do it for you then use a console mode zipper like 7-zip.
To show output folder in windows explorer to the user, it's simply enough to do this:
Process.Start("explorer.exe", OutputDir);

Restart application with Kill process id [duplicate]

Developing a C# .NET 2.0 WinForm Application. Need the application to close and restart itself.
Application.Restart();
The above method has proven to be unreliable.
What is a better way to restart the application?
A much simpler approach that worked for me is:
Application.Restart();
Environment.Exit(0);
This preserves the command-line arguments and works despite event handlers that would normally prevent the application from closing.
The Restart() call tries to exit, starts a new instance anyway and returns. The Exit() call then terminates the process without giving any event handlers a chance to run. There is a very brief period in which both processes are running, which is not a problem in my case, but maybe in other cases.
The exit code 0 in Environment.Exit(0); specifies a clean shutdown. You can also exit with 1 to specify an error occurred.
If you are in main app form try to use
System.Diagnostics.Process.Start( Application.ExecutablePath); // to start new instance of application
this.Close(); //to turn off current app
Unfortunately you can't use Process.Start() to start an instance of the currently running process. According to the Process.Start() docs:
"If the process is already running, no additional process resource is started..."
This technique will work fine under the VS debugger (because VS does some kind of magic that causes Process.Start to think the process is not already running), but will fail when not run under the debugger. (Note that this may be OS-specific - I seem to remember that in some of my testing, it worked on either XP or Vista, but I may just be remembering running it under the debugger.)
This technique is exactly the one used by the last programmer on the project on which I'm currently working, and I've been trying to find a workaround for this for quite some time. So far, I've only found one solution, and it just feels dirty and kludgy to me: start a 2nd application, that waits in the background for the first application to terminate, then re-launches the 1st application. I'm sure it would work, but, yuck.
Edit: Using a 2nd application works. All I did in the second app was:
static void RestartApp(int pid, string applicationName )
{
// Wait for the process to terminate
Process process = null;
try
{
process = Process.GetProcessById(pid);
process.WaitForExit(1000);
}
catch (ArgumentException ex)
{
// ArgumentException to indicate that the
// process doesn't exist? LAME!!
}
Process.Start(applicationName, "");
}
(This is a very simplified example. The real code has lots of sanity checking, error handling, etc)
I might be late to the party but here is my simple solution and it works like a charm with every application I have:
try
{
//run the program again and close this one
Process.Start(Application.StartupPath + "\\blabla.exe");
//or you can use Application.ExecutablePath
//close this one
Process.GetCurrentProcess().Kill();
}
catch
{ }
I had the same exact problem and I too had a requirement to prevent duplicate instances - I propose an alternative solution to the one HiredMind is proposing (which will work fine).
What I am doing is starting the new process with the processId of the old process (the one that triggers the restart) as a cmd line argument:
// Shut down the current app instance.
Application.Exit();
// Restart the app passing "/restart [processId]" as cmd line args
Process.Start(Application.ExecutablePath, "/restart" + Process.GetCurrentProcess().Id);
Then when the new app starts I first parse the cm line args and check if the restart flag is there with a processId, then wait for that process to Exit:
if (_isRestart)
{
try
{
// get old process and wait UP TO 5 secs then give up!
Process oldProcess = Process.GetProcessById(_restartProcessId);
oldProcess.WaitForExit(5000);
}
catch (Exception ex)
{
// the process did not exist - probably already closed!
//TODO: --> LOG
}
}
I am obviously not showing all the safety checks that I have in place etc.
Even if not ideal - I find this a valid alternative so that you don't have to have in place a separate app just to handle restart.
Start/Exit Method
// Get the parameters/arguments passed to program if any
string arguments = string.Empty;
string[] args = Environment.GetCommandLineArgs();
for (int i = 1; i < args.Length; i++) // args[0] is always exe path/filename
arguments += args[i] + " ";
// Restart current application, with same arguments/parameters
Application.Exit();
System.Diagnostics.Process.Start(Application.ExecutablePath, arguments);
This seems to work better than Application.Restart();
Not sure how this handles if your program protects against multiple instance. My guess is you would be better off launching a second .exe which pauses and then starts your main application for you.
It's simple, you just need to call the Application.Restart() method, this will invoke your application to be restarted. You must also exit from the local environment with an error code:
Application.Restart();
Environment.Exit(int errorcode);
You can create an enumeration of error codes so that you application will exit efficeintly.
Another method is to just exit from the application and start the process using the executable path:
Application.Exit();
System.Diagnostics.Process.Start(Application.ExecutablePath);
Try this code:
bool appNotRestarted = true;
This code must also be in the function:
if (appNotRestarted == true) {
appNotRestarted = false;
Application.Restart();
Application.ExitThread();
}
I figured an another solution out, perhaps anyone can use it, too.
string batchContent = "/c \"#ECHO OFF & timeout /t 6 > nul & start \"\" \"$[APPPATH]$\" & exit\"";
batchContent = batchContent.Replace("$[APPPATH]$", Application.ExecutablePath);
Process.Start("cmd", batchContent);
Application.Exit();
Code is simplified so take care of Exceptions and stuff ;)
I fear that restarting the entire application using Process is approaching your problem in the wrong way.
An easier way is to modify the Program.cs file to restart:
static bool restart = true; // A variable that is accessible from program
static int restartCount = 0; // Count the number of restarts
static int maxRestarts = 3; // Maximum restarts before quitting the program
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
while (restart && restartCount < maxRestarts)
{
restart = false; // if you like.. the program can set it to true again
restartCount++; // mark another restart,
// if you want to limit the number of restarts
// this is useful if your program is crashing on
// startup and cannot close normally as it will avoid
// a potential infinite loop
try {
Application.Run(new YourMainForm());
}
catch { // Application has crashed
restart = true;
}
}
}
You are forgetting the command-line options/parameters that were passed in to your currently running instance. If you don't pass those in, you are not doing a real restart. Set the Process.StartInfo with a clone of your process' parameters, then do a start.
For example, if your process was started as myexe -f -nosplash myfile.txt, your method would only execute myexe without all those flags and parameters.
I wanted the new application start up after the old one shuts down.
Using process.WaitForExit() to wait for your own process to shutdown makes no sense. It will always time out.
So, my approach is to use Application.Exit() then wait, but allow events to be processed, for a period of time. Then start a new application with the same arguments as the old.
static void restartApp() {
string commandLineArgs = getCommandLineArgs();
string exePath = Application.ExecutablePath;
try {
Application.Exit();
wait_allowingEvents( 1000 );
} catch( ArgumentException ex ) {
throw;
}
Process.Start( exePath, commandLineArgs );
}
static string getCommandLineArgs() {
Queue<string> args = new Queue<string>( Environment.GetCommandLineArgs() );
args.Dequeue(); // args[0] is always exe path/filename
return string.Join( " ", args.ToArray() );
}
static void wait_allowingEvents( int durationMS ) {
DateTime start = DateTime.Now;
do {
Application.DoEvents();
} while( start.Subtract( DateTime.Now ).TotalMilliseconds > durationMS );
}
You could also use Restarter.
Restarter is an application that automatically monitor and restarts crashed or hung programs and applications. It was originally developed to monitor and restart game servers, but it will do the job for any console or form based program or application
public static void appReloader()
{
//Start a new instance of the current program
Process.Start(Application.ExecutablePath);
//close the current application process
Process.GetCurrentProcess().Kill();
}
Application.ExecutablePath returns your aplication .exe file path
Please follow the order of calls. You might want to place it in a try-catch clause.
The problem of using Application.Restart() is, that it starts a new process but the "old" one is still remaining. Therefor I decided to Kill the old process by using the following code snippet:
if(Condition){
Application.Restart();
Process.GetCurrentProcess().Kill();
}
And it works proper good. In my case MATLAB and a C# Application are sharing the same SQLite database. If MATLAB is using the database, the Form-App should restart (+Countdown) again, until MATLAB reset its busy bit in the database. (Just for side information)
How about create a bat file, run the batch file before closing, and then close the current instance.
The batch file does this:
wait in a loop to check whether the process has exited.
start the process.
Here's my 2 cents:
The sequence Start New Instance->Close Current Instance should work even for the applications that don't allow running multiple copies simultaneously as in this case the new instance may be passed a command-line argument which will indicate that there is a restart in progress so checking for other instances running will not be necessary. Waiting for the first instance to actually finish my be implemented too if it's absolutely imperative that no two intstances are running in parallel.
Application.Restart();
Environment.Exit(0);
I had a similar problem, but mine was related to unmanageable memory leak that I couldn't find on an app that has to run 24/7. With the customer I agreed that safe time to restart the app was 03:00AM if the memory consumption was over the defined value.
I tried Application.Restart, but since it seems to use some mechanism that starts new instance while it is already running, I went for another scheme. I used the trick that file system handles persist until process that created them dies. So, from The Application, i dropped the file to the disk, and didn't Dispose() the handle. I used the file to send 'myself' executable and starting directory also (to add flexibility).
Code:
_restartInProgress = true;
string dropFilename = Path.Combine(Application.StartupPath, "restart.dat");
StreamWriter sw = new StreamWriter(new FileStream(dropFilename, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite));
sw.WriteLine(Application.ExecutablePath);
sw.WriteLine(Application.StartupPath);
sw.Flush();
Process.Start(new ProcessStartInfo
{
FileName = Path.Combine(Application.StartupPath, "VideoPhill.Restarter.exe"),
WorkingDirectory = Application.StartupPath,
Arguments = string.Format("\"{0}\"", dropFilename)
});
Close();
Close() at the end would initiate app shutdown, and file handle I used for StreamWriter here would be held open until process really dies. Then...
Restarter.exe comes into action. It TRIES to read the file in exclusive mode, preventing it to gain access until main app wasn't dead, then starts main app, deletes the file and exists. I guess that it can't be simpler:
static void Main(string[] args)
{
string filename = args[0];
DateTime start = DateTime.Now;
bool done = false;
while ((DateTime.Now - start).TotalSeconds < 30 && !done)
{
try
{
StreamReader sr = new StreamReader(new FileStream(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite));
string[] runData = new string[2];
runData[0] = sr.ReadLine();
runData[1] = sr.ReadLine();
Thread.Sleep(1000);
Process.Start(new ProcessStartInfo { FileName = runData[0], WorkingDirectory = runData[1] });
sr.Dispose();
File.Delete(filename);
done = true;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Thread.Sleep(1000);
}
}
I use the following and it does exactly what you are looking for:
ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
UpdateCheckInfo info = null;
info = ad.CheckForDetailedUpdate();
if (info.IsUpdateRequired)
{
ad.UpdateAsync(); // I like the update dialog
MessageBox.Show("Application was upgraded and will now restart.");
Environment.Exit(0);
}
for using As logout you need to terminate all app from Ram Cache
so close The Application first and then Rerun it
//on clicking Logout Button
foreach(Form frm in Application.OpenForms.Cast<Form>().ToList())
{
frm.Close();
}
System.Diagnostics.Process.Start(Application.ExecutablePath);
You could enclose your code inside a function and when restart is needed you can just call the function.
Take for instance an application that:
While application is not registered; (upon start) the application should prompt the user to register the application and create a login account.
Once registration is submitted and login credentials are created; the application should restart, check for registration and prompt the user to login with the inserted credentials (so the user can access to all the application features).
Problem:
By building and launching the application from Visual Studio; any of the 4 alternatives bellow will fail to accomplish the tasks required.
/*
* Note(s):
* Take into consideration that the lines bellow don't represent a code block.
* They are just a representation of possibilities,
* that can be used to restart the application.
*/
Application.Restart();
Application.Exit();
Environment.Exit(int errorCode);
Process.GetCurrentProcess().Kill();
What happens is: After creating the Registration, Login and calling Application.Restart(); the application will (strangely) reopen the Registration Form and skip data in a Database (even though the resource is set to "Copy if Newer").
Solution:
Batch Building the application was (for me) a proof that any of the lines above were actually working as expected.
Just not when building and running the application with Visual Studio.
In first place I'd try batch building the application; run it outside Visual Studio and check if Application.Restart() actually works as expected.
Also Check further Info regarding this thread subject:
How do I restart my C# WinForm Application?
I've found a new way that's pretty convenient and has quite a few upsides.
There's never more than one instance running.
Command line args are persisted.
No exit events are raised from the application.
No process handles are broken.
I had a third party application managing my application with Process.Start and using Exit event to reload the application. Many of these solutions would break this implementation which is how I ended up on the following solution.
public static CancellationTokenSource _restartTokenSource;
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main(string[] args)
{
// To customize application configuration such as set high DPI settings or default font,
// see https://aka.ms/applicationconfiguration.
ApplicationConfiguration.Initialize();
while (_restartTokenSource == null || _restartTokenSource.IsCancellationRequested)
{
_restartTokenSource = new System.Threading.CancellationTokenSource();
_restartTokenSource.Token.Register(() =>
{
foreach (Form form in Application.OpenForms)
form.Close();
});
Application.Run(new FlashMain(args));
}
}
Since Application.Run blocks until all forms in the application are closed I put this portion of the initialization into a loop that only executes when a CancellationTokenSource is null (the first run) or IsCancellationRequested is true (restart requested).
I register an event on the CancellationTokenSource that closes all forms in the application when .Cancel() is called, therefore unblocking Application.Run and restarting the loop.
Call Program._restartTokenSource.Cancel(); anywhere in the application to restart it.
P.S. This also works great for injecting into a BlazorWebView to restart the application from .NET Core.

Process.Start() and continue with my code

My program is in win forms (c#). It should open an external program, do a printscreen of it's main window, and close it.
By using Process.Start() I can open the the program, but then all the focus is on it and my code is halted. Only when I close it myself my form continues- but it's too late for the screenshot.
So how do I force my code to keep running?
public void Runttk(string maromnum)
{
Process runttk = new Process();
runttk.StartInfo.UseShellExecute = true;
runttk.StartInfo.FileName = #"C:\\program.exe";
runttk.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
runttk.Start();
this.Focus();
try
{
if (runttk.WaitForInputIdle()==true)
{
PringJpg(maromnum);
Killttk();
}
}
catch (Exception e)
{
}
}
Thank you
UPDATE:
eventuanlly I've used Thread.Sleep(3000). Crued but do the trick.
I didn't used backgroundworker because the sync between the finale uplaod the the extenral program and my code wasn't clear enough.
Trying your code, but with another program like notepad.exe, Notepad runs and then control drops through to where you call PringJpg.
So I think the problem is that it is blocking on if (runttk.WaitForInputIdle()==true), please try adding a timeout to this operation.
Maybe your programm is never idle - means that runttk.WaitForInputIdle()==true let your app wait until you close it.
Add a limit ( for example runttk.WaitForInputIdle(500)==true) should fulfill your needings.

Starting a process without stealing focus (C#)

I need to be able to start processes (both console and windowed) without it stealing focus. The only way within the .NET framework that I found to do this is Microsoft.VisualBasic.Interaction.Shell with Microsoft.VisualBasic.AppWinStyle.[Minimized|Normal]NoFocus (which map to SW_SHOWMINNOACTIVE/SW_SHOWMA being passed through to ShellExecute).
In the current version of my code (which does steal focus), I am using System.Diagnostics.Process, and relying on some of the functionality that gives me, which the Interaction.Shell method does not.
2 questions (one serious, and one venting my frustration that I don't really expect a good answer to)
1.) Am I correct that I have no choice but to wrap CreateProcess or ShellExecuteEx myself, or am I missing some other solution? I was really hoping to avoid this, as Process is such a complete and useful wrapper other than this oversight, and there would be so much functionality to implement, P/Invoke calls to debug, and all sorts of assorted pain.
2.) Why would one team at Microsoft create such a (otherwise) complete wrapper, and then exclude half of the possible values from ProcessWindowStyle, while another team created a similar wrapper that was much less complete, but provided all the useful window styles?
The VB.Net team has done much more to ease things for the developer regarding instrumentation of windows, and I see no problem adding a reference to a VB dll and use that in your C# program.
It's two teams with different focus, that's all. And you shouldn't feel bad about using Microsoft.VisualBasic.Interaction.Shell if it solves your issue.
You can also use Reflector to see the actual implementation and implement the code yourself if you don't want to reference the dll.
[Edit - added code example after comment to show you can combine Interaction.Shell and Process]
int pid = Interaction.Shell("notepad.exe", AppWinStyle.NormalFocus);
Process p = Process.GetProcessById(pid);
p.Exited += ((o, e) => Console.WriteLine("Exit"));
p.EnableRaisingEvents = true;
Console.ReadLine();
Here I use the Shell method to kick off the process, get a handle to the process from the pid, and hook on events. You can even do p.Kill() in order to abort the process.
[Edit - workaround for cmd.exe]
It's starting to become a bit hackish to my taste, but it works. Replace "NEWWINDOW" with a random guid or something to make it unique.
Microsoft.VisualBasic.Interaction.Shell(#"cmd.exe /c ""start cmd.exe /k title NEWWINDOW""", AppWinStyle.NormalFocus);
foreach (var process in Process.GetProcessesByName("cmd"))
{
if (process.MainWindowTitle.EndsWith("NEWWINDOW"))
{
process.Exited += ((o, e) => Console.WriteLine("Exit"));
process.EnableRaisingEvents = true;
}
}
Have a look here:
System.Diagnostics.ProcessStartInfo procInfo = new System.Diagnostics.ProcessStartInfo();
procInfo.CreateNoWindow = true;
procInfo.UseShellExecute = true;
procInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo = procInfo;
proc.EnableRaisingEvents = true;
proc.Exited += new EventHandler(proc_Exited);
proc.OutputDataReceived += new DataReceivedEventHandler(proc_OutputDataReceived);
proc.Start(...)
// Do something with proc.Handle...
void proc_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
/* Do something here... */
}
void proc_Exited(object sender, EventArgs e)
{
/* Do something here... */
}
Edit: I have modified the code to show the means of raising events and handling them, also, I have shown the usage of the Handle property which is the handle of the process that is running.

How do I restart my C# WinForm Application?

Developing a C# .NET 2.0 WinForm Application. Need the application to close and restart itself.
Application.Restart();
The above method has proven to be unreliable.
What is a better way to restart the application?
A much simpler approach that worked for me is:
Application.Restart();
Environment.Exit(0);
This preserves the command-line arguments and works despite event handlers that would normally prevent the application from closing.
The Restart() call tries to exit, starts a new instance anyway and returns. The Exit() call then terminates the process without giving any event handlers a chance to run. There is a very brief period in which both processes are running, which is not a problem in my case, but maybe in other cases.
The exit code 0 in Environment.Exit(0); specifies a clean shutdown. You can also exit with 1 to specify an error occurred.
If you are in main app form try to use
System.Diagnostics.Process.Start( Application.ExecutablePath); // to start new instance of application
this.Close(); //to turn off current app
Unfortunately you can't use Process.Start() to start an instance of the currently running process. According to the Process.Start() docs:
"If the process is already running, no additional process resource is started..."
This technique will work fine under the VS debugger (because VS does some kind of magic that causes Process.Start to think the process is not already running), but will fail when not run under the debugger. (Note that this may be OS-specific - I seem to remember that in some of my testing, it worked on either XP or Vista, but I may just be remembering running it under the debugger.)
This technique is exactly the one used by the last programmer on the project on which I'm currently working, and I've been trying to find a workaround for this for quite some time. So far, I've only found one solution, and it just feels dirty and kludgy to me: start a 2nd application, that waits in the background for the first application to terminate, then re-launches the 1st application. I'm sure it would work, but, yuck.
Edit: Using a 2nd application works. All I did in the second app was:
static void RestartApp(int pid, string applicationName )
{
// Wait for the process to terminate
Process process = null;
try
{
process = Process.GetProcessById(pid);
process.WaitForExit(1000);
}
catch (ArgumentException ex)
{
// ArgumentException to indicate that the
// process doesn't exist? LAME!!
}
Process.Start(applicationName, "");
}
(This is a very simplified example. The real code has lots of sanity checking, error handling, etc)
I might be late to the party but here is my simple solution and it works like a charm with every application I have:
try
{
//run the program again and close this one
Process.Start(Application.StartupPath + "\\blabla.exe");
//or you can use Application.ExecutablePath
//close this one
Process.GetCurrentProcess().Kill();
}
catch
{ }
I had the same exact problem and I too had a requirement to prevent duplicate instances - I propose an alternative solution to the one HiredMind is proposing (which will work fine).
What I am doing is starting the new process with the processId of the old process (the one that triggers the restart) as a cmd line argument:
// Shut down the current app instance.
Application.Exit();
// Restart the app passing "/restart [processId]" as cmd line args
Process.Start(Application.ExecutablePath, "/restart" + Process.GetCurrentProcess().Id);
Then when the new app starts I first parse the cm line args and check if the restart flag is there with a processId, then wait for that process to Exit:
if (_isRestart)
{
try
{
// get old process and wait UP TO 5 secs then give up!
Process oldProcess = Process.GetProcessById(_restartProcessId);
oldProcess.WaitForExit(5000);
}
catch (Exception ex)
{
// the process did not exist - probably already closed!
//TODO: --> LOG
}
}
I am obviously not showing all the safety checks that I have in place etc.
Even if not ideal - I find this a valid alternative so that you don't have to have in place a separate app just to handle restart.
Start/Exit Method
// Get the parameters/arguments passed to program if any
string arguments = string.Empty;
string[] args = Environment.GetCommandLineArgs();
for (int i = 1; i < args.Length; i++) // args[0] is always exe path/filename
arguments += args[i] + " ";
// Restart current application, with same arguments/parameters
Application.Exit();
System.Diagnostics.Process.Start(Application.ExecutablePath, arguments);
This seems to work better than Application.Restart();
Not sure how this handles if your program protects against multiple instance. My guess is you would be better off launching a second .exe which pauses and then starts your main application for you.
It's simple, you just need to call the Application.Restart() method, this will invoke your application to be restarted. You must also exit from the local environment with an error code:
Application.Restart();
Environment.Exit(int errorcode);
You can create an enumeration of error codes so that you application will exit efficeintly.
Another method is to just exit from the application and start the process using the executable path:
Application.Exit();
System.Diagnostics.Process.Start(Application.ExecutablePath);
Try this code:
bool appNotRestarted = true;
This code must also be in the function:
if (appNotRestarted == true) {
appNotRestarted = false;
Application.Restart();
Application.ExitThread();
}
I figured an another solution out, perhaps anyone can use it, too.
string batchContent = "/c \"#ECHO OFF & timeout /t 6 > nul & start \"\" \"$[APPPATH]$\" & exit\"";
batchContent = batchContent.Replace("$[APPPATH]$", Application.ExecutablePath);
Process.Start("cmd", batchContent);
Application.Exit();
Code is simplified so take care of Exceptions and stuff ;)
I fear that restarting the entire application using Process is approaching your problem in the wrong way.
An easier way is to modify the Program.cs file to restart:
static bool restart = true; // A variable that is accessible from program
static int restartCount = 0; // Count the number of restarts
static int maxRestarts = 3; // Maximum restarts before quitting the program
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
while (restart && restartCount < maxRestarts)
{
restart = false; // if you like.. the program can set it to true again
restartCount++; // mark another restart,
// if you want to limit the number of restarts
// this is useful if your program is crashing on
// startup and cannot close normally as it will avoid
// a potential infinite loop
try {
Application.Run(new YourMainForm());
}
catch { // Application has crashed
restart = true;
}
}
}
You are forgetting the command-line options/parameters that were passed in to your currently running instance. If you don't pass those in, you are not doing a real restart. Set the Process.StartInfo with a clone of your process' parameters, then do a start.
For example, if your process was started as myexe -f -nosplash myfile.txt, your method would only execute myexe without all those flags and parameters.
I wanted the new application start up after the old one shuts down.
Using process.WaitForExit() to wait for your own process to shutdown makes no sense. It will always time out.
So, my approach is to use Application.Exit() then wait, but allow events to be processed, for a period of time. Then start a new application with the same arguments as the old.
static void restartApp() {
string commandLineArgs = getCommandLineArgs();
string exePath = Application.ExecutablePath;
try {
Application.Exit();
wait_allowingEvents( 1000 );
} catch( ArgumentException ex ) {
throw;
}
Process.Start( exePath, commandLineArgs );
}
static string getCommandLineArgs() {
Queue<string> args = new Queue<string>( Environment.GetCommandLineArgs() );
args.Dequeue(); // args[0] is always exe path/filename
return string.Join( " ", args.ToArray() );
}
static void wait_allowingEvents( int durationMS ) {
DateTime start = DateTime.Now;
do {
Application.DoEvents();
} while( start.Subtract( DateTime.Now ).TotalMilliseconds > durationMS );
}
You could also use Restarter.
Restarter is an application that automatically monitor and restarts crashed or hung programs and applications. It was originally developed to monitor and restart game servers, but it will do the job for any console or form based program or application
public static void appReloader()
{
//Start a new instance of the current program
Process.Start(Application.ExecutablePath);
//close the current application process
Process.GetCurrentProcess().Kill();
}
Application.ExecutablePath returns your aplication .exe file path
Please follow the order of calls. You might want to place it in a try-catch clause.
The problem of using Application.Restart() is, that it starts a new process but the "old" one is still remaining. Therefor I decided to Kill the old process by using the following code snippet:
if(Condition){
Application.Restart();
Process.GetCurrentProcess().Kill();
}
And it works proper good. In my case MATLAB and a C# Application are sharing the same SQLite database. If MATLAB is using the database, the Form-App should restart (+Countdown) again, until MATLAB reset its busy bit in the database. (Just for side information)
How about create a bat file, run the batch file before closing, and then close the current instance.
The batch file does this:
wait in a loop to check whether the process has exited.
start the process.
Here's my 2 cents:
The sequence Start New Instance->Close Current Instance should work even for the applications that don't allow running multiple copies simultaneously as in this case the new instance may be passed a command-line argument which will indicate that there is a restart in progress so checking for other instances running will not be necessary. Waiting for the first instance to actually finish my be implemented too if it's absolutely imperative that no two intstances are running in parallel.
Application.Restart();
Environment.Exit(0);
I had a similar problem, but mine was related to unmanageable memory leak that I couldn't find on an app that has to run 24/7. With the customer I agreed that safe time to restart the app was 03:00AM if the memory consumption was over the defined value.
I tried Application.Restart, but since it seems to use some mechanism that starts new instance while it is already running, I went for another scheme. I used the trick that file system handles persist until process that created them dies. So, from The Application, i dropped the file to the disk, and didn't Dispose() the handle. I used the file to send 'myself' executable and starting directory also (to add flexibility).
Code:
_restartInProgress = true;
string dropFilename = Path.Combine(Application.StartupPath, "restart.dat");
StreamWriter sw = new StreamWriter(new FileStream(dropFilename, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite));
sw.WriteLine(Application.ExecutablePath);
sw.WriteLine(Application.StartupPath);
sw.Flush();
Process.Start(new ProcessStartInfo
{
FileName = Path.Combine(Application.StartupPath, "VideoPhill.Restarter.exe"),
WorkingDirectory = Application.StartupPath,
Arguments = string.Format("\"{0}\"", dropFilename)
});
Close();
Close() at the end would initiate app shutdown, and file handle I used for StreamWriter here would be held open until process really dies. Then...
Restarter.exe comes into action. It TRIES to read the file in exclusive mode, preventing it to gain access until main app wasn't dead, then starts main app, deletes the file and exists. I guess that it can't be simpler:
static void Main(string[] args)
{
string filename = args[0];
DateTime start = DateTime.Now;
bool done = false;
while ((DateTime.Now - start).TotalSeconds < 30 && !done)
{
try
{
StreamReader sr = new StreamReader(new FileStream(filename, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite));
string[] runData = new string[2];
runData[0] = sr.ReadLine();
runData[1] = sr.ReadLine();
Thread.Sleep(1000);
Process.Start(new ProcessStartInfo { FileName = runData[0], WorkingDirectory = runData[1] });
sr.Dispose();
File.Delete(filename);
done = true;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Thread.Sleep(1000);
}
}
I use the following and it does exactly what you are looking for:
ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
UpdateCheckInfo info = null;
info = ad.CheckForDetailedUpdate();
if (info.IsUpdateRequired)
{
ad.UpdateAsync(); // I like the update dialog
MessageBox.Show("Application was upgraded and will now restart.");
Environment.Exit(0);
}
for using As logout you need to terminate all app from Ram Cache
so close The Application first and then Rerun it
//on clicking Logout Button
foreach(Form frm in Application.OpenForms.Cast<Form>().ToList())
{
frm.Close();
}
System.Diagnostics.Process.Start(Application.ExecutablePath);
You could enclose your code inside a function and when restart is needed you can just call the function.
Take for instance an application that:
While application is not registered; (upon start) the application should prompt the user to register the application and create a login account.
Once registration is submitted and login credentials are created; the application should restart, check for registration and prompt the user to login with the inserted credentials (so the user can access to all the application features).
Problem:
By building and launching the application from Visual Studio; any of the 4 alternatives bellow will fail to accomplish the tasks required.
/*
* Note(s):
* Take into consideration that the lines bellow don't represent a code block.
* They are just a representation of possibilities,
* that can be used to restart the application.
*/
Application.Restart();
Application.Exit();
Environment.Exit(int errorCode);
Process.GetCurrentProcess().Kill();
What happens is: After creating the Registration, Login and calling Application.Restart(); the application will (strangely) reopen the Registration Form and skip data in a Database (even though the resource is set to "Copy if Newer").
Solution:
Batch Building the application was (for me) a proof that any of the lines above were actually working as expected.
Just not when building and running the application with Visual Studio.
In first place I'd try batch building the application; run it outside Visual Studio and check if Application.Restart() actually works as expected.
Also Check further Info regarding this thread subject:
How do I restart my C# WinForm Application?
I've found a new way that's pretty convenient and has quite a few upsides.
There's never more than one instance running.
Command line args are persisted.
No exit events are raised from the application.
No process handles are broken.
I had a third party application managing my application with Process.Start and using Exit event to reload the application. Many of these solutions would break this implementation which is how I ended up on the following solution.
public static CancellationTokenSource _restartTokenSource;
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main(string[] args)
{
// To customize application configuration such as set high DPI settings or default font,
// see https://aka.ms/applicationconfiguration.
ApplicationConfiguration.Initialize();
while (_restartTokenSource == null || _restartTokenSource.IsCancellationRequested)
{
_restartTokenSource = new System.Threading.CancellationTokenSource();
_restartTokenSource.Token.Register(() =>
{
foreach (Form form in Application.OpenForms)
form.Close();
});
Application.Run(new FlashMain(args));
}
}
Since Application.Run blocks until all forms in the application are closed I put this portion of the initialization into a loop that only executes when a CancellationTokenSource is null (the first run) or IsCancellationRequested is true (restart requested).
I register an event on the CancellationTokenSource that closes all forms in the application when .Cancel() is called, therefore unblocking Application.Run and restarting the loop.
Call Program._restartTokenSource.Cancel(); anywhere in the application to restart it.
P.S. This also works great for injecting into a BlazorWebView to restart the application from .NET Core.

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