Win32进程创建顺序

Question

I would like to enumerate all the instances of an application and determine which instance was created first (oldest). Given a list of HWNDs that belong to the process instances, can I sort the list to determine the order of creation? If not, is there another way?

EDIT 1 : the windows being enumerated are not created by my process, they were created long before my process started execution.

EDIT 2: As mentioned in the comments, I am interested in the creation time of the processed. I need the HWND of he main window of the oldest instance of the application. Not sure how to get the HWND from the process ID.

Answer 1

There are two different ways you can approach this:

1. Start with the windows

   • Use EnumWindows() , or a FindWindow/Ex() loop, to find the candidate app windows you are interested in. In the case of EnumWindows() , you can use things like GetClassName() and GetWindowText() in the callback.

   • Use GetWindowThreadProcessId() to get each window's PID.

   • Use OpenProcess() to open each PID, and GetProcessTimes() to get its creation time.

   • Now you can sort the times to get the oldest, and you will know the window(s) that go with the corresponding process.

2. Start with the processes

   • Use EnumProcesses() , or a Process32(First|Next)() loop, to find the PIDs of each instance of the app path+filename you are interested in.

   • Use OpenProcess() and GetProcessTimes() to get their creation times, and then sort them.

   • Then, with the oldest PID, you can enumerate windows looking for the one(s) that belong to that PID. You can either:

     1. enumerate all windows as above, using GetWindowThreadProcessId() to look for the PID.

     2. use EnumThreadWindows() on each thread of the process. To get the process's thread IDs, you can use a Thread32(First|Next)() loop.

        Optionally, assuming the process's main thread is the one creating the window(s) you want, you can limit the window enumeration to just that thread. Enumerate the pricess's threads, using OpenThread() and GetThreadTimes() to find the oldest thread ID, which will be the main thread.