Learn how to make the program run only one instance

Method 1:
Static void Main ()
{

System. Threading. Mutex mutex;

Bool isNew;

Mutex = new System. Threading. Mutex (true, "myproject", out isNew );

If (isNew)

{

Application. EnableVisualStyles ();

Application. SetCompatibleTextRenderingDefault (false );

Application. Run (new Login ());

}

Else

{

MessageBox. Show ("this program is already running! "," Message ", MessageBoxButtons. OK, MessageBoxIcon. Warning );

}

}

 

Method 2 (a running window is displayed) to allow the program to run only one instance ):
Static void Main ()
{

Process instance = RunningInstance ();

If (instance = null)

{

Application. EnableVisualStyles ();

Application. SetCompatibleTextRenderingDefault (false );

Application. Run (new Login ());

}

Else

{

HandleRunningInstance (instance );

}

 

}

 

// Return the running program process

Public static Process RunningInstance ()
{

Process current = Process. GetCurrentProcess ();

Process [] processes = Process. GetProcessesByName (current. ProcessName );

Foreach (Process process in processes)

{

If (process. Id! = Current. Id)

{

If (Assembly. GetExecutingAssembly (). Location. Replace ("/", "\") = current. MainModule. FileName)

{

Return process;

}

}

}

Return null; // The first run, returns null

}

// Display the current window of the running process

Public static void HandleRunningInstance (Process instance)
{

ShowWindowAsync (instance. main1_whandle, WS_SHOWNORMAL); // set the window to normal

SetForegroundWindow (instance. main1_whandle );

}

 

# Region calls the system api

[DllImport ("User32.dll")]

Private static extern bool ShowWindowAsync (IntPtr hWnd, int cmdShow );

[DllImport ("User32.dll")]

Private static extern bool SetForegroundWindow (IntPtr hWnd );

Private const int WS_SHOWNORMAL = 1;

# Endregion

Author: pukuimin1226