Get window handle from process id

Get window handle from process id

• yfradkin

  That's the process ID you want, GetWindowThreadProcessId() sets it. Just declare a variable and pass it (well, actually reference/pointer to it) to GetWindowThreadProcessId(), after that variable would be set to process ID:

  uint processId;

  GetWindowThreadProcessId(hwnd, out processId);

  // processId now contains process ID for hwnd.

  
  
  

• Ben Hall (UK)

  Thank you very much Ilya, your replies was very helpful

  THANK YOU

  
  
  

• Dache

  Dear Ilya,

  thanks alot for your reply.

  here is my declaration

  [DllImport("coredll")] public static extern uint
  GetWindowThreadProcessId(IntPtr hwnd, out uint lpdwProcessId);

  but i don't know what is the lpdwProcessId i'd be grateful if you could tell me where to get it.

  thanks

  
  
  

• tolily

  Enumerate all windows (EnumWindows()), get process ID for each one (GetWindowThreadProcessId()). Compare it with process ID you've got and if the same you found your window.

  
  
  

• Vlince

  Hi,

  this is the api call i used

  [DllImport("coredll")]
  public static extern uint GetWindowThreadProcessId(IntPtr hwnd);

  but strangely returned IDs that doesn't match with any of the running processes!!

  even when  i try to kill the processes using these strange ids using

  System.Diagnostics.Process.GetProcessById(  the obtained id  ).Kill();

  i recieve and exception saying that this process is not running!!!!

  do you have any suggestions

  thanks alot

   

  
  
  

• John Luke

  Your declaration is incorrect. GetWindowThreadProcessId() takes two arguments one of which is a pointer to the process ID to get back and it’s missing from your declaration.  Returned value is a thread ID which is why it does not match any process ID. Here’s the function prototype:
   
  DWORD GetWindowThreadProcessId(
    HWND hWnd, 
    LPDWORD lpdwProcessId 
  );
   
  

  
  
  
• Get window handle from process id