c# - When set a process handle window position to screen center it's working but not in all cases why? -

in form1 if process not yet running run bring front , center screen center. if process running bring front , center it:

if (autoit.autoitx.winexists(existingprocessname, "") == 0) // window not found             {                 int processid = autoit.autoitx.run(processfilename, "", autoit.autoitx.sw_show);                 setprocesswindow.bringtofront(processid);                 setprocesswindow.centerprocesswindow(processid);                 thread.sleep(10000);                 autoit.autoitx.mouseclick("left", 358, 913, 1, -1);              }             else             {                 process[] processes = process.getprocessesbyname(processname);                 setprocesswindow. bringtofront(processes[0].id);                 setprocesswindow.centerprocesswindow(processes[0].id);                 thread.sleep(10000);                 autoit.autoitx.mouseclick("left", 358, 913, 1, -1);             } 

and class setprocesswindow:

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.runtime.interopservices; using system.diagnostics; using system.windows.forms; using system.drawing;  namespace usingautoit {     class setprocesswindow     {         [dllimport("user32.dll")]         public static extern bool setforegroundwindow(intptr hwnd);          [dllimport("user32.dll")]         [return: marshalas(unmanagedtype.bool)]         static extern bool getwindowrect(intptr hwnd, out rect lprect);          [structlayout(layoutkind.sequential)]         public struct rect         {             public int left;        // x position of upper-left corner             public int top;         // y position of upper-left corner             public int right;       // x position of lower-right corner             public int bottom;      // y position of lower-right corner         }          private const int swp_nosize = 0x0001;         private const int swp_nozorder = 0x0004;         private const int swp_showwindow = 0x0040;          [dllimport("user32.dll", setlasterror = true)]         static extern bool setwindowpos(intptr hwnd, intptr hwndinsertafter, int x, int y, int cx, int cy, int uflags);          public static void bringtofront(int processid)         {             process process = process.getprocessbyid(processid);             intptr handle = process.mainwindowhandle;              if (handle == intptr.zero)                 return;              setforegroundwindow(handle);         }          public static void centerprocesswindow(int processid)         {             process process = process.getprocessbyid(processid);             intptr handle = process.mainwindowhandle;              if (handle != intptr.zero)             {                 rect rct;                 getwindowrect(handle, out rct);                 rectangle screen = screen.fromhandle(handle).bounds;                 point pt = new point(screen.left + screen.width / 2 - (rct.right - rct.left) / 2, screen.top + screen.height / 2 - (rct.bottom - rct.top) / 2);                 setwindowpos(handle, intptr.zero, pt.x, pt.y, 0, 0, swp_nozorder | swp_nosize | swp_showwindow);             }           }     } } 

the problem if process running , drag process window 1 of screen corners click on empty in screen process in background , running program bring process handle window front , center it.

but if drag process window somewhere in screen not center , quit process running program , it's running process bring front not center it.

why when process not running , program running process dosent center ?

your process window shown immediately, it's not set won't results debugging because if go through debugger enough time pass , handle created work fine you. need wait mainwindowhandle set. can modify centerprocesswindow method this:

public static void centerprocesswindow(int processid) {     process process = process.getprocessbyid(processid);      while (process.mainwindowhandle == intptr.zero)         process.refresh();      intptr handle = process.mainwindowhandle;      rect rct;     getwindowrect(handle, out rct);     rectangle screen = screen.fromhandle(handle).bounds;     point pt = new point(screen.left + screen.width / 2 - (rct.right - rct.left) / 2, screen.top + screen.height / 2 - (rct.bottom - rct.top) / 2);     setwindowpos(handle, intptr.zero, pt.x, pt.y, 0, 0, swp_nozorder | swp_nosize | swp_showwindow); }