c# - How do i return a false or true each process so i can monitor if the process is in front or not? -

in form1 have timer:

private void form1_load(object sender, eventargs e)         {             system.windows.forms.timer t1 = new system.windows.forms.timer();             t1.interval = 50;             t1.tick += new eventhandler(timer1_tick);             t1.enabled = true;         } 

the tick event:

private void timer1_tick(object sender, eventargs e)         {            label4.text =  setprocesswindow.applicationisactivated().tostring();                     } 

and applicationisactivated method:

public static bool applicationisactivated()         {              process[] processes = process.getprocesses();             foreach (process singleprocess in processes)             {                 var activatedhandle = getforegroundwindow();                 if (activatedhandle == intptr.zero)                 {                     return false;                 }                 var procid = singleprocess.id;//process.getcurrentprocess().id;                 int activeprocid;                 getwindowthreadprocessid(activatedhandle, out activeprocid);                  return activeprocid == procid;             }                     } 

i want somehow monitor processes , if move process front show me in label4 in form1.

applicationisactivated not written good. first i'm not sure if making foreach each time , second i'm not sure how return activeprocid == procid; per process.

instead of checking if each process activated one, can find activated process directly:

process findactivatedprocess() {     var activatedhandle = getforegroundwindow();     if (activatedhandle == intptr.zero)         return null;    // no window has focus      int activeprocid;     getwindowthreadprocessid(activatedhandle, out activeprocid);     return process.getprocessbyid(activeprocid); }  [dllimport("user32.dll", charset = charset.auto, exactspelling = true)] private static extern intptr getforegroundwindow();  [dllimport("user32.dll", charset = charset.auto, setlasterror = true)] private static extern int getwindowthreadprocessid(intptr handle, out int processid); 

to determine when activated application changes, can polling (though suggest larger interval -- 50ms seems overkill me), or can ask windows notify when happens.