Develop Reference

How to run Outlook using Process.Start("outlook.exe") and get the control back

My C# program needs to launch Office Outlook and get the current "running outlook application".
In order to do that I've implemented the following simple program (so if you want you can test it simply):
using Outlook = Microsoft.Office.Interop.Outlook;
using System.Runtime.InteropServices;
static void Main(string[] args)
{
Outlook.Application outlookObj = null;
if (Process.GetProcessesByName("OUTLOOK").Count().Equals(0))
{
Process.Start("outlook.exe"); // MY PROGRAM STOPS HERE
}
var process = Process.GetProcessesByName("OUTLOOK").First();
while (!process.HasExited)
{
try
{
outlookObj = (Outlook.Application)Marshal.GetActiveObject("Outlook.Application");
break;
}
catch
{
outlookObj = null;
}
System.Threading.Thread.Sleep(10);
}
string result = (outlookObj== null)? "DOES NOT WORK" : "OK";
Console.WriteLine(result);
Console.ReadLine();
}
My problem is that once Office Outlook starts running then my C# console application does not continue its job. After the Process.Start("outlook.exe"); instruction is executed then I must click on Visual Studio GUI in order to restart the console application and finally read "OK" on my console application.
How can I solve my problem?

Microsoft wrote a example about how to log into a outlook instance. Although this is directly what you asked for in your question, the example contains how to start a new outlook application in the intended way
application = new Outlook.Application();
as a side note: in your example you use the following code:
while (!process.HasExited)
{
try
{
outlookObj = (Outlook.Application)Marshal.GetActiveObject("Outlook.Application");
break;
}
catch
{
outlookObj = null;
}
System.Threading.Thread.Sleep(10);
}
This is bad practice in your main thread as your applying 'busy waiting' by using the thread.sleep. This means you will 1. use CPU power while your application is doing nothing. 2. make your GUI completely unresponsive and if the thread.sleep is called to many times Windows will suggest to shut the process down (the whole screen gets white and eventually you get a popup asking you if you want to wait or just shut it down). There are plenty of ways in the .net framework to prevent both of these issues (for example using a waithandle, background worker or locking)

There is no need to run the a new process using the Process.Start method. Instead, you can add the Outlook reference to your C# project and create a new instance of the Application class. See C# app automates Outlook (CSAutomateOutlook) sample project for more information.
Also you may find the following articles helpful:
How to automate Outlook and Word by using Visual C# .NET to create a pre-populated e-mail message that can be edited
How to use Visual C# to automate a running instance of an Office program

This works:
public static void StartOutlookIfNotRunning()
{
string OutlookFilepath = #"C:\Program Files (x86)\Microsoft Office\Office12\OUTLOOK.EXE";
if (Process.GetProcessesByName("OUTLOOK").Count() > 0) return;
Process process = new Process();
process.StartInfo = new ProcessStartInfo(OutlookFilepath);
process.Start();
}

Use the Process.Start overload that takes a ProcessStartInfo instead so you can set UseShellExecute
var startInfo = new ProcessStartInfo()
{
FileName = "Outlook.exe",
UseShellExecute = true
};
Process.Start(startInfo);

MAYBE the process need some time to start.
Try this:
if (Process.GetProcessesByName("OUTLOOK").Count().Equals(0))
{
Process.Start("outlook.exe"); // MY PROGRAM STOPS HERE
}
while ((Process.GetProcessesByName("OUTLOOK").Count().Equals(0));
var process = Process.GetProcessesByName("OUTLOOK").First();
This should cause starting process and waiting until it is avaible before trying to catch it...

How to check a Window already opened when button is clicked?

I am Working in Visual Studio 2008 Winforms Application project in Windows 7 (32 bit).I am doing the project in C#.
I have placed some buttons in a tab and added actions for that once it is clicked. While clicking the button am just running a .exe file in its action part.
My problem is that, i opened a window by clicking one button(so the .exe file is running), now while am clicking the button again it is opening same window again irrespective of checking that it is open or not. I want to solve this issue,as when a window is opened it must not open again on another click on same button. How to solve this issue. ?
Please help....
Thanks in advance..

You could check if the process is already running, when re-clicking the button:
private void btnStartExecutable_Click(object sender, EventArgs e)
{
Process[] processName = Process.GetProcessesByName("InsertProcessNameHere");
if (pname.Length == 0)
{
MessageBox.Show("Application isn't running yet.");
//Start application here
Process.Start("InsertProcessNameHere");
}
else
{
MessageBox.Show("Application is already running.");
//Don't start application, since it has been started already
}
}

You can try this:
bool processExited = true;
private void button1_Click(object sender, EventArgs e)
{
if (processExited)
{
Process process = new Process();
process.EnableRaisingEvents = true;
process.Exited += MyProcessExited;
process.StartInfo = new ProcessStartInfo();
process.StartInfo.FileName = "notepad.exe";
process.Start();
processExited = false;
}
else
{
MessageBox.Show("Still running");
}
}
void MyProcessExited(object sender, EventArgs e)
{
processExited = true;
}

The right answer here IMHO is that unless the two application shares a common resource or can talk to each other through some channel, there is no safe and efficient way to achieve what you want. Since the process is external, it could already be running before your calling app starts, or even while it's already running. You won't be able to tell if the process has been started from your app or not.
By the time I'm writing this your question does not yet state if you are in liberty to modify the external app you are calling. If you are however, using a Mutex would be a quick and easy way to solve your problem.
In your external app, whenever you want to make the other app aware of whatever condition you want (be it that the process is running or that a specific window is opened), have a Mutex instance created like this:
var mutex = new Threading.Mutex(true, "mutex unique identifier");
And in your calling app, try to create a Mutex instance with the same identifier:
bool alreadyExists;
var mutex = new Threading.Mutex(false, "mutex unique identifier", out alreadyExists);
Here the alreadyExists variable will tell you whether or not the external process is running or not. This is much safer than trying to identify it via its name, as other processes could have the same or a new version could be of a different name. Of course, the mutex identifier must be as unique as possible (like a Guid), otherwise you may encounter the same problem. ;)
Whenever you feel like the mutex must be released (at external app level), release it:
mutex.ReleaseMutex();
Note that if the process ends the mutex will be automatically released by the OS.
If the external app isn't a .NET based app, you can still create a mutex with Win32 API functions.

Thanks for the support.. I got the answer like this..
1) Creating an event'Exit' for the process in function button click
2) Define a function for the exit event where you set a flag
3) Check the flag is set or not everytime while opening the process in the function button click
Event for Exit: 'P' is the name of process:
p.Exited += new EventHandler(p_Exited);
p_Exited will be the function name where we will set the flag.
Thanks all...

If you know the name of the process that gets started or the path the .exe is run from you can use the Process class to check to see if it is currently running.
http://msdn.microsoft.com/en-us/library/system.diagnostics.process(v=vs.110).aspx

Windows Mobile 6.5 Process.Start

I have a GUI application which starts two command line applications ( no window, just processes ) on Windows Mobile 6.5. I am using following code to start process:
Process service = new Process();
var pi = new ProcessStartInfo(exePath, null);
pi.UseShellExecute = false;
service.StartInfo = pi;
//start the process
service.Start();
Everything works fine, except, when service.Start() is called, my GUI application is covered by a circle thingy rotating in the center of the screen. Same Icon that rotates while waiting for a program to start, means OS is busy. Now since these processes will run for the life time of the GUI and even after GUI will quit, this circle does not go away. Is there a way to make it go away, via code? i tried Invalidating gui to repaint and changing cursor to normal. Dosnt work?
Any ideas?

What does exePath launch?
My guess is that Simon McKenzie has already nailed this one on the head. That is probably exactly what is going on.
However, the OS will also throw up a WaitCursor (the circle thingy rotating in the center of the screen) whenever it starts up some intensive CPU process. If that is the case, you may want to rethink how to approach this process you are launching - particularly if you are the one who wrote the process.
Consider the hypothetical application below to poll the network and compiled to your exePath:
while (true) {
if (networkDataAvailable()) {
processData();
}
}
That hypothetical application would be eating away at the processor's idle time.
If the process you are launching does something like that, you'll need to find another way to approach the problem like calling a simpler process in a timer tick event.
The modified process identified by the exePath would now be:
if (networkDataAvailable()) {
processData();
}
And from your Windows application, you could call this as needed like so:
private void timer1_Tick(object sender, EventArgs e) {
Process service = new Process();
var pi = new ProcessStartInfo(exePath, null);
pi.UseShellExecute = false;
service.StartInfo = pi;
//start the process
service.Start();
}

It sounds like the call to service.Start() may be blocking the main thread. Perhaps you could try starting your process in a new thread:
private void StartProcess()
{
Process service = new Process();
var pi = new ProcessStartInfo(exePath, null);
pi.UseShellExecute = false;
service.StartInfo = pi;
//start the process
service.Start();
}
...
Thread t = new Thread(StartProcess);
t.Start();

This is difficult to diagnose without understanding more about what the process you are starting up in exePath is doing. If that process throws up a wait cursor and monopolizes the CPU it may explain the behaviour you are seeing.

Verify that another application is always running

I'm trying to make a console app in c# that will confirm that another application is always running. The other application periodically crashes, and I need to check every few minutes and relaunch it if it has stopped working.
There are many questions on SO that address making sure than no more than one instance of the application is running. I'm trying to confirm that one (no more or less) is running at all times.
Does anybody know how to even begin approaching this?

I would suggest using System.Diagnostics.Process.GetProcessesByName to see if your process is running and then, if not, using System.Diagnostics.Process.Start to start the process.
var processes = Process.GetProcessesByName("yourProcessName");
if(processes.Length == 0)
{
Process.Start(#"C:\Path\To\Your\Process.exe");
}
// Kill the extras
for(int i = 1; i < process.Length; i++)
{
processes[i].Kill();
}

These commands are useful to control processes:
// check for processes
Process[] processes = Process.GetProcessesByName("nameOfExecutable");
foreach (Process proc in processes)
{
// do stuff
}
// start process (need path)
Process.Start("pathToExecutable");
// close gui process gently (if needed)
bool status = proc.CloseMainWindow();
// wait for process to close gently
bool status = proc.WaitForExit(killTimeMS);
// force close (kill) process
proc.Kill();

If you implement a "no more than one" rule (which is well-documented, as you point out) and then implement the periodic crash-checker, that should be sufficient to ensure that one and only one copy is running.
In fact, the periodic process doesn't even have to check for a crash. It can just fire up an instance, which will immediately exit if another instance is already running, thanks to whatever "no more than one" mechanism you implement. This has the added benefit of avoiding a possible race-condition between detecting a dead process and starting a new one.

You have a few options. The first is checking for a running process using the Process class. I got this from a Microsoft site, but it looks like it works:
public bool IsProcessRunning(string name)
{
//here we're going to get a list of all running processes on
//the computer
foreach (Process clsProcess in Process.GetProcesses())
{
if (clsProcess.ProcessName.StartsWith(name))
{
//process found so it's running so return true
return true;
}
}
//process not found, return false
return false;
}
You could also use interprocess communications. This is something we do in house. We have a watcher application that sends a message to a service being monitored. If the service doesn't return an ACK in a timeout period, we attempt to restart it.

I suggest you to check if your application is in the list of running processes:
System.Diagnostics.Process.GetProcesses();

Kill process tree programmatically in C#

I am starting Internet Explorer programmatically with code that looks like this:
ProcessStartInfo startInfo = new ProcessStartInfo("iexplore.exe");
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.Arguments = "http://www.google.com";
Process ieProcess = Process.Start(startInfo);
This generates 2 processes visible in the Windows Task Manager. Then, I attempt to kill the process with:
ieProcess.Kill();
This results in one of the processes in Task Manager being shut down, and the other remains. I tried checking for any properties that would have children processes, but found none. How can I kill the other process also? More generally, how do you kill all the processes associated with a process that you start with Process.Start?

This worked very nicely for me:
/// <summary>
/// Kill a process, and all of its children, grandchildren, etc.
/// </summary>
/// <param name="pid">Process ID.</param>
private static void KillProcessAndChildren(int pid)
{
// Cannot close 'system idle process'.
if (pid == 0)
{
return;
}
ManagementObjectSearcher searcher = new ManagementObjectSearcher
("Select * From Win32_Process Where ParentProcessID=" + pid);
ManagementObjectCollection moc = searcher.Get();
foreach (ManagementObject mo in moc)
{
KillProcessAndChildren(Convert.ToInt32(mo["ProcessID"]));
}
try
{
Process proc = Process.GetProcessById(pid);
proc.Kill();
}
catch (ArgumentException)
{
// Process already exited.
}
}
Update 2016-04-26
Tested on Visual Studio 2015 Update 2 on Win7 x64. Still works as well now as it did 3 years ago.
Update 2017-11-14
Added check for system idle process if (pid == 0)
Update 2018-03-02
Need to add a reference to the System.Management namespace, see comment from #MinimalTech below. If you have ReSharper installed, it will offer to do this for you automatically.
Update 2018-10-10
The most common use case for this is killing any child processes that our own C# process has started.
In this case, a better solution is to use Win32 calls within C# to make any spawned process a child process. This means that when the parent process exits, any child processes are automatically closed by Windows, which eliminates the need for the code above. Please let me know if you want me to post the code.

If anyone needs a dotnet core solution,
Dotnet core 3.0
process.Kill(true);
See official documentation
Dotnet core 2.0
For .Net 2.0 dotnet cli came up with an implementation based on taskill as mentioned above and recursive pgrep/kill for unix based systems. Full implementation can be found on github. Sadly, the class is internal so you'll have to copy it into your code base.
List Child processes (has to be done recursively):
$"pgrep -P {parentId}"
Kill on process:
$"kill -TERM {processId}"

I'm not a fan of any of the solutions presented here.
Here's what I came up with:
private static void EndProcessTree(string imageName)
{
Process.Start(new ProcessStartInfo
{
FileName = "taskkill",
Arguments = $"/im {imageName} /f /t",
CreateNoWindow = true,
UseShellExecute = false
}).WaitForExit();
}
How to use:
EndProcessTree("chrome.exe");
Process Class (System.Diagnostics)
ProcessStartInfo Class (System.Diagnostics)
Taskkill

You should call Process.CloseMainWindow() which will send a message to the main window of the process. Think of it as having the user click the "X" close button or File | Exit menu item.
It is safer to send a message to Internet Explorer to close itself down, than go and kill all its processes. Those processes could be doing anything and you need to let IE do its thing and finish before just killing it in the middle of doing something that may be important for future runs. This goes true for any program you kill.

If anyone is interested, I took one of the answers from the other page and modified it slightly. It is a self contained class now with static methods. It does not have proper error handling or logging. Modify to use for your own needs. Providing your root Process to KillProcessTree will do it.
class ProcessUtilities
{
public static void KillProcessTree(Process root)
{
if (root != null)
{
var list = new List<Process>();
GetProcessAndChildren(Process.GetProcesses(), root, list, 1);
foreach (Process p in list)
{
try
{
p.Kill();
}
catch (Exception ex)
{
//Log error?
}
}
}
}
private static int GetParentProcessId(Process p)
{
int parentId = 0;
try
{
ManagementObject mo = new ManagementObject("win32_process.handle='" + p.Id + "'");
mo.Get();
parentId = Convert.ToInt32(mo["ParentProcessId"]);
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
parentId = 0;
}
return parentId;
}
private static void GetProcessAndChildren(Process[] plist, Process parent, List<Process> output, int indent)
{
foreach (Process p in plist)
{
if (GetParentProcessId(p) == parent.Id)
{
GetProcessAndChildren(plist, p, output, indent + 1);
}
}
output.Add(parent);
}
}

Another solution is to use the taskill command. I use the next code in my applications:
public static void Kill()
{
try
{
ProcessStartInfo processStartInfo = new ProcessStartInfo("taskkill", "/F /T /IM your_parent_process_to_kill.exe")
{
WindowStyle = ProcessWindowStyle.Hidden,
CreateNoWindow = true,
UseShellExecute = false,
WorkingDirectory = System.AppDomain.CurrentDomain.BaseDirectory,
RedirectStandardOutput = true,
RedirectStandardError = true
};
Process.Start(processStartInfo);
}
catch { }
}

Are you using IE8 or IE9? That would absolutely start more than one process due to its new multi-process architecture. Anyway, have a look at this other answer for getting a process tree and killing it.

Another approach that can be very useful is using the Windows API for Job Objects. A process can be assigned to a job object. The child processes of such a process are automatically assigned to the same job object.
All processes assigned to a job object can be killed at once e.g. with TerminateJobObject which:
Terminates all processes currently associated with the job.
The C# example in this answer (based on this answer) uses the JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE flag instead, which:
Causes all processes associated with the job to terminate when the last handle to the job is closed.

With .NET Core 3.0 there is a method just for that, namely new overload of the already existing Process.Kill() method. IOW, doing process.Kill(true) on the variable process of type Process kills the process with all its descendants. This is cross-platform, naturally.

As per documentation
The Kill method executes asynchronously. After calling the Kill method, call the WaitForExit method to wait for the process to exit, or check the HasExited property to determine if the process has exited.
ProcessStartInfo startInfo = new ProcessStartInfo("iexplore.exe");
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.Arguments = "http://www.google.com";
Process ieProcess = Process.Start(startInfo);
ieProcess.Kill();
ieProcess.WaitForExit();

How to properly close Internet Explorer when launched from PowerShell?
Several of those commented in the above thread that this is caused by a bug in Win7 (as it does not seem to occur for users that are using other versions of windows). Many pages on the internet, including microsoft's page claim user error, and tell you to simply use the available quit method on the IE object which is SUPPOSED to close all child processes as well (and reportedly does in Win8/XP etc)
I must admit, for my part, it WAS user error. I am in win7 and the reason the quit method was not working for me was because of an error in coding. Namely I was creating the IE object at declaration, and then creating another (attached to the same object) later on in the code... I had almost finished hacking the parent-child killing routine to work for me when I realized the issue.
Because of how IE functions, the processID you spawned as the parent could be attached to other windows/subprocesses that you did NOT create. Use quit, and keep in mind that depending on user settings (like empty cache on exit) it could take a few minutes for the processes to finish their tasks and close.