blocks|key|1351997|text|看一看this+question|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1351998|有一个指向本文的链接：the+misunderstood+mutex，其中解释了互斥锁的用法。|1351999|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/777744/how-can-i-check-for-a-running-process-per-user-session|1|http://odetocode.com/Blogs/scott/archive/2004/08/20/401.aspx^0|3|D|0|0|B|N|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@$A|U|B|V|1|W]]|C|$]]|$1|F|3|-4|5|6|7|X|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]]]

Have a look at <a href="https://stackoverflow.com/questions/777744/how-can-i-check-for-a-running-process-per-user-session">this question</a>

There is a link to this article: <a href="http://odetocode.com/Blogs/scott/archive/2004/08/20/401.aspx" rel="nofollow noreferrer">the misunderstood mutex</a> where the usage of a mutex is explained.

blocks|key|1567487|text|我曾经这样做过一次，我希望它能有所帮助：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1567488|bool+createdNew;

Mutex+m+=+new+Mutex(true,+"myApp",+out+createdNew);

if+(!createdNew)
{
++++//+myApp+is+already+running...
++++MessageBox.Show("myApp+is+already+running!",+"Multiple+Instances");
++++return;
}|code-block|syntax|javascript|1567489|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I did it this way once, I hope it helps:

<pre><code>bool createdNew;

Mutex m = new Mutex(true, "myApp", out createdNew);

if (!createdNew)
{
 // myApp is already running...
 MessageBox.Show("myApp is already running!", "Multiple Instances");
 return;
}
</code></pre>

blocks|key|1352064|text|还有这个。Is+using+a+Mutex+to+prevent+multiple+instances+of+the+same+program+from+running+safe?|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1352065|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/646480/is-using-a-mutex-to-prevent-multipule-instances-of-the-same-program-from-running^0|5|2D|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Also this. <a href="https://stackoverflow.com/questions/646480/is-using-a-mutex-to-prevent-multipule-instances-of-the-same-program-from-running">Is using a Mutex to prevent multiple instances of the same program from running safe?</a>

blocks|key|1352141|text|查看this+page上显示的代码示例|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1352142|简而言之，您使用重载互斥锁ctor(bool,+string,+out+bool)，它通过一个out参数告诉您是否获得了命名互斥锁的所有权。如果您是第一个实例，则在调用ctor之后，此out参数将包含true+-在这种情况下，您可以像往常一样处理。如果此参数为false，则意味着另一个实例已获得所有权/正在运行，在这种情况下，您将显示错误消息“另一个实例已在运行”。然后优雅地退出。|style|CODE|1352143|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/bwe34f1k.aspx^0|2|9|0|0|D|S|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@$A|U|B|V|F|G]]|9|@]|C|$]]|$1|H|3|-4|5|6|7|W|8|@]|9|@]|C|$]]]|I|$J|$5|K|L|M|C|$N|O]]]]

Check out the code sample shown on <a href="http://msdn.microsoft.com/en-us/library/bwe34f1k.aspx" rel="nofollow noreferrer">this page</a>
In short, you use the overload Mutex <code>ctor(bool, string, out bool)</code> which tells you via an out parameter, whether you got ownership of the Named Mutex. If you're the first instance, this out param would contain true after the ctor is called - in which case you proceed as usual. If this param is false, it means another instance has already got ownership/is running, in which case you show an error message &quot;Another instance is already running.&quot; and then exit gracefully.

blocks|key|1567600|text|static+void+Main()+
{
++using(Mutex+mutex+=+new+Mutex(false,+@"Global\"+%2B+appGuid))
++{
++++if(!mutex.WaitOne(0,+false))
++++{
+++++++MessageBox.Show("Instance+already+running");
+++++++return;
++++}

++++GC.Collect();++++++++++++++++
++++Application.Run(new+Form1());
++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1567601|来源：http://odetocode.com/Blogs/scott/archive/2004/08/20/401.aspx|unstyled|offset|length|1567602|entityMap|0|LINK|mutability|MUTABLE|url|http://odetocode.com/Blogs/scott/archive/2004/08/20/401.aspx^0|0|3|1O|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@$G|S|H|T|1|U]]|A|$]]|$1|I|3|-4|5|F|7|V|8|@]|9|@]|A|$]]]|J|$K|$5|L|M|N|A|$O|P]]]]

<pre><code>static void Main() 
{
 using(Mutex mutex = new Mutex(false, @"Global\" + appGuid))
 {
 if(!mutex.WaitOne(0, false))
 {
 MessageBox.Show("Instance already running");
 return;
 }

 GC.Collect(); 
 Application.Run(new Form1());
 }
}
</code></pre>

Source : <a href="http://odetocode.com/Blogs/scott/archive/2004/08/20/401.aspx" rel="noreferrer">http://odetocode.com/Blogs/scott/archive/2004/08/20/401.aspx</a>

blocks|key|1352191|text|我使用的是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1352192|++++private+static+Mutex+_mutex;

++++private+static+bool+IsSingleInstance()
++++{
++++++++_mutex+=+new+Mutex(false,+_mutexName);

++++++++//+keep+the+mutex+reference+alive+until+the+normal+
++++++++//termination+of+the+program
++++++++GC.KeepAlive(_mutex);

++++++++try
++++++++{
++++++++++++return+_mutex.WaitOne(0,+false);
++++++++}
++++++++catch+(AbandonedMutexException)
++++++++{
++++++++++++//+if+one+thread+acquires+a+Mutex+object+
++++++++++++//that+another+thread+has+abandoned+
++++++++++++//by+exiting+without+releasing+it

++++++++++++_mutex.ReleaseMutex();
++++++++++++return+_mutex.WaitOne(0,+false);
++++++++}
++++}


++++public+Form1()
++++{
++++++++if+(!isSingleInstance())
++++++++{
++++++++++++MessageBox.Show("Instance+already+running");
++++++++++++this.Close();
++++++++++++return;
++++++++}

++++++++//program+body+here
++++}

++++private+void+Form1_FormClosing(object+sender,+FormClosingEventArgs+e)
++++{
++++++++if+(_mutex+!=+null)
++++++++{
++++++++++++_mutex.ReleaseMutex();
++++++++}
++++}++++|code-block|syntax|javascript|1352193|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I use this:

<pre><code> private static Mutex _mutex;

 private static bool IsSingleInstance()
 {
 _mutex = new Mutex(false, _mutexName);

 // keep the mutex reference alive until the normal 
 //termination of the program
 GC.KeepAlive(_mutex);

 try
 {
 return _mutex.WaitOne(0, false);
 }
 catch (AbandonedMutexException)
 {
 // if one thread acquires a Mutex object 
 //that another thread has abandoned 
 //by exiting without releasing it

 _mutex.ReleaseMutex();
 return _mutex.WaitOne(0, false);
 }
 }


 public Form1()
 {
 if (!isSingleInstance())
 {
 MessageBox.Show("Instance already running");
 this.Close();
 return;
 }

 //program body here
 }

 private void Form1_FormClosing(object sender, FormClosingEventArgs e)
 {
 if (_mutex != null)
 {
 _mutex.ReleaseMutex();
 }
 } 
</code></pre>

blocks|key|1567658|text|使用具有超时和安全设置的应用程序。我使用了我的自定义类：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1567659|private+class+SingleAppMutexControl+:+IDisposable
++++{
++++++++private+readonly+Mutex+_mutex;
++++++++private+readonly+bool+_hasHandle;

++++++++public+SingleAppMutexControl(string+appGuid,+int+waitmillisecondsTimeout+=+5000)
++++++++{
++++++++++++bool+createdNew;
++++++++++++var+allowEveryoneRule+=+new+MutexAccessRule(new+SecurityIdentifier(WellKnownSidType.WorldSid,+null),
++++++++++++++++MutexRights.FullControl,+AccessControlType.Allow);
++++++++++++var+securitySettings+=+new+MutexSecurity();
++++++++++++securitySettings.AddAccessRule(allowEveryoneRule);
++++++++++++_mutex+=+new+Mutex(false,+"Global\\"+%2B+appGuid,+out+createdNew,+securitySettings);
++++++++++++_hasHandle+=+false;
++++++++++++try
++++++++++++{
++++++++++++++++_hasHandle+=+_mutex.WaitOne(waitmillisecondsTimeout,+false);
++++++++++++++++if+(_hasHandle+==+false)
++++++++++++++++++++throw+new+System.TimeoutException();
++++++++++++}
++++++++++++catch+(AbandonedMutexException)
++++++++++++{
++++++++++++++++_hasHandle+=+true;
++++++++++++}
++++++++}

++++++++public+void+Dispose()
++++++++{
++++++++++++if+(_mutex+!=+null)
++++++++++++{
++++++++++++++++if+(_hasHandle)
++++++++++++++++++++_mutex.ReleaseMutex();
++++++++++++++++_mutex.Dispose();
++++++++++++}
++++++++}
++++}|code-block|syntax|javascript|1567660|并使用它：|1567661|++++private+static+void+Main(string[]+args)
++++{
++++++++try
++++++++{
++++++++++++const+string+appguid+=+"{xxxxxxxx-xxxxxxxx}";
++++++++++++using+(new+SingleAppMutexControl(appguid))
++++++++++++{

++++++++++++++++Console.ReadLine();
++++++++++++}
++++++++}
++++++++catch+(System.TimeoutException)
++++++++{
++++++++++++Log.Warn("Application+already+runned");
++++++++}
++++++++catch+(Exception+ex)
++++++++{
++++++++++++Log.Fatal(ex,+"Fatal+Error+on+running");
++++++++}
++++}|1567662|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Use app with timeout and security settings. I used my custom class:

<pre><code>private class SingleAppMutexControl : IDisposable
 {
 private readonly Mutex _mutex;
 private readonly bool _hasHandle;

 public SingleAppMutexControl(string appGuid, int waitmillisecondsTimeout = 5000)
 {
 bool createdNew;
 var allowEveryoneRule = new MutexAccessRule(new SecurityIdentifier(WellKnownSidType.WorldSid, null),
 MutexRights.FullControl, AccessControlType.Allow);
 var securitySettings = new MutexSecurity();
 securitySettings.AddAccessRule(allowEveryoneRule);
 _mutex = new Mutex(false, "Global\\" + appGuid, out createdNew, securitySettings);
 _hasHandle = false;
 try
 {
 _hasHandle = _mutex.WaitOne(waitmillisecondsTimeout, false);
 if (_hasHandle == false)
 throw new System.TimeoutException();
 }
 catch (AbandonedMutexException)
 {
 _hasHandle = true;
 }
 }

 public void Dispose()
 {
 if (_mutex != null)
 {
 if (_hasHandle)
 _mutex.ReleaseMutex();
 _mutex.Dispose();
 }
 }
 }
</code></pre>

and use it:

<pre><code> private static void Main(string[] args)
 {
 try
 {
 const string appguid = "{xxxxxxxx-xxxxxxxx}";
 using (new SingleAppMutexControl(appguid))
 {

 Console.ReadLine();
 }
 }
 catch (System.TimeoutException)
 {
 Log.Warn("Application already runned");
 }
 catch (Exception ex)
 {
 Log.Fatal(ex, "Fatal Error on running");
 }
 }
</code></pre>

In order to allow only a single instance of an application running I'm using mutex. The code is given below. Is this the right way to do it? Are there any flaws in the code?

How to show the already running application when user tries to open the application the second time. At present (in the code below), I'm just displaying a message that another instance is already running.

<pre><code> static void Main(string[] args)
 {
 Mutex _mut = null;

 try
 {
 _mut = Mutex.OpenExisting(AppDomain.CurrentDomain.FriendlyName);
 }
 catch
 {
 //handler to be written
 }

 if (_mut == null)
 {
 _mut = new Mutex(false, AppDomain.CurrentDomain.FriendlyName);
 }
 else
 {
 _mut.Close();
 MessageBox.Show("Instance already running");

 } 
 }
</code></pre>

Run single instance of an application using Mutex

为了只允许运行一个应用程序的单个实例，我使用了互斥。代码如下所示。这是正确的做法吗？代码中有什么缺陷吗？当用户再次尝试打开应用程序时，如何显示已经运行的应用程序。目前(在下面的代码中)，我只是显示一条消息，表明另一个实例已经在运行。    static void Main(string[] args)    {    ...

问使用互斥锁运行应用程序的单个实例
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