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How to get the Handle Id from Process, HWND programmatically?


I try to get Handle ID of opened applications (windows).

I run Window detective program, (like spy++) to verify that I get proper values.

For testing I try to get only one Handle Id pointed by red arrow (see the image):

enter image description here

So I have program that gives me process id and thread Id but not 1st Child Handle ID.

In my case I took calc.exe, but actually I need to do that for all exe applications:

readWindow.c

#include <windows.h>
#include <stdio.h>
#include <stddef.h>
#include <inttypes.h>
#include <tchar.h> 
#include <psapi.h> 

HMODULE getModulePid(DWORD processID, char* searchStr){ // gets the module by the module name from an explicit process

   HANDLE hProcess;
   HMODULE hMods[1024];
   TCHAR szModName[MAX_PATH];
   DWORD cbNeeded;

   if(hProcess = OpenProcess( PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID ))
   {
    if(EnumProcessModules(hProcess, hMods, sizeof(hMods), &cbNeeded))
    {
    unsigned int k;
    for(k = 0; k < (cbNeeded / sizeof(HMODULE)); ++k )
    {
        if (GetModuleFileNameEx(hProcess, hMods[k], szModName,  sizeof(szModName)/sizeof(TCHAR)))
        {

        //printf( "fess pid: %u modname: %s\n", processID, szModName );

        if(strstr(szModName, searchStr))
        {
            printf( "pid: &#37;u modname: %s\n", processID, szModName );
            CloseHandle( hProcess );
            return hMods[k];
        }
       }
    }//for
  }     
}  
    CloseHandle( hProcess );
    return NULL;
}

HMODULE getModule(char* searchStr){ // gets the module by the modul name from all processes
   DWORD aProcesses[1024], cbNeeded, cProcesses;

    if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return NULL;
    cProcesses = cbNeeded / sizeof(DWORD);

    HMODULE hmodule;
    unsigned int i;
    for (i = 0; i < cProcesses; ++i )
    {
        if(hmodule = getModulePid(aProcesses[i], searchStr))
         {
         return hmodule;
          }
         }
    return NULL;
}


HMODULE getModuleHwnd(HWND hwnd){ // gets the module from a window
   DWORD pid;
   DWORD tid = GetWindowThreadProcessId(hwnd, &pid ); // !!??!!
   printf( "hwnd tid: %u\n", tid  );
    printf( "hwnd pid: %u\n", pid  );
   return getModulePid(pid, ".exe");
}

HMODULE hModuleT;
char* searchStrT;

BOOL CALLBACK shownWindow(HWND hwnd, LPARAM lParam){ // EnumWindows callback
   if(hModuleT) return TRUE;

    char pcWinTitle[256];

    if(GetWindow(hwnd, GW_OWNER)) return TRUE; // whats that?
    GetWindowText(hwnd, pcWinTitle, 1024);
    if(strstr(pcWinTitle, searchStrT)){  
        printf( "wndtitle: %s\n", pcWinTitle);                                      
        hModuleT = getModuleHwnd(hwnd);
    }

    return TRUE;
}

HMODULE getModuleByWndTitle(char* searchStr){ // gets the module from a window title
    searchStrT = searchStr;
    EnumWindows(shownWindow, 0);
    return hModuleT;
}


int main()
{

    //EnumWindows(EnumWindowsProc, 0);

    printf("find by name ... \n");
     getModule("calc.exe");
     printf("\nfind by title ... \n");
   getModuleByWndTitle("Calculator");

    printf("Done");


    return 0;
} 

Run from minGW:

$ gcc -L/local/lib -I/local/include -o readWindow readWindow.c -lpsapi

Output:

find by title ...
wndtitle: Calculator
hwnd tid: 33364
hwnd pid: 25440
Done

How can I get the Handle from Process?

I'm sure it should be some 1-2 rows of code.

DWORD dwValue .....

printf("The value in hexa: 0X%.8X(%d).\n", dwValue);

it should be 0x007B137C

From Spy++ I need this value, red arrow:

enter image description here


Solution

  • It was pretty easy but for me tricky a bit.

    I just need to print pointer HWND hwnd with %p.

    So I added to my code:

    char szBuff[512];
    sprintf(szBuff, "%p", hwnd);
    
    printf( "Found .... hWnd: %s\n", szBuff); 
    

    And got what I need:

    Found .... hWnd: 007B137C
    

    [EDIT]

    Working code example:

    readWindow.c

    #include <windows.h>
    #include <stdio.h>
    #include <stddef.h>
    #include <inttypes.h>
    #include <tchar.h> 
    #include <psapi.h> 
    
    HMODULE getModulePid(DWORD processID, char* searchStr){ // gets the module by the module name from an explicit process
    
       HANDLE hProcess;
       HMODULE hMods[1024];
       TCHAR szModName[MAX_PATH];
       DWORD cbNeeded;
    
       if(hProcess = OpenProcess( PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID ))
       {
        if(EnumProcessModules(hProcess, hMods, sizeof(hMods), &cbNeeded))
        {
        unsigned int k;
        for(k = 0; k < (cbNeeded / sizeof(HMODULE)); ++k )
        {
            if (GetModuleFileNameEx(hProcess, hMods[k], szModName,  sizeof(szModName)/sizeof(TCHAR)))
            {
    
            //printf( "fess pid: %u modname: %s\n", processID, szModName );
    
            if(strstr(szModName, searchStr))
            {
                printf( "pid: &#37;u modname: %s\n", processID, szModName );
                CloseHandle( hProcess );
                return hMods[k];
            }
           }
        }//for
      }     
    }  
        CloseHandle( hProcess );
        return NULL;
    }
    
    HMODULE getModule(char* searchStr){ // gets the module by the modul name from all processes
       DWORD aProcesses[1024], cbNeeded, cProcesses;
    
        if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return NULL;
        cProcesses = cbNeeded / sizeof(DWORD);
    
        HMODULE hmodule;
        unsigned int i;
        for (i = 0; i < cProcesses; ++i )
        {
            if(hmodule = getModulePid(aProcesses[i], searchStr))
             {
             return hmodule;
              }
             }
        return NULL;
    }
    
    
    HMODULE getModuleHwnd(HWND hwnd){ // gets the module from a window
       DWORD pid;
       DWORD tid = GetWindowThreadProcessId(hwnd, &pid ); // !!??!!
       printf( "hwnd tid: %u\n", tid  );
        printf( "hwnd pid: %u\n", pid  );
       return getModulePid(pid, ".exe");
    }
    
    HMODULE hModuleT;
    char* searchStrT;
    
    BOOL CALLBACK shownWindow(HWND hwnd, LPARAM lParam){ // EnumWindows callback
       if(hModuleT) return TRUE;
    
        char pcWinTitle[256];
    
        if(GetWindow(hwnd, GW_OWNER)) return TRUE; // whats that?
        GetWindowText(hwnd, pcWinTitle, 1024);
    
        if(strstr(pcWinTitle, searchStrT))
        {  
            printf( "wndtitle: %s\n", pcWinTitle);                                      
            hModuleT = getModuleHwnd(hwnd);
    
            char szBuff[512];
           sprintf(szBuff, "%p", hwnd);
    
           printf( "Found .... hWnd: %s\n", szBuff); 
    
        }
    
        return TRUE;
    }
    
    HMODULE getModuleByWndTitle(char* searchStr){ // gets the module from a window title
        searchStrT = searchStr;
        EnumWindows(shownWindow, 0);
        return hModuleT;
    }
    
    
    int main()
    {
    
        //EnumWindows(EnumWindowsProc, 0);
    
        printf("find by name ... \n");
         getModule("calc.exe");
         printf("\nfind by title ... \n");
       getModuleByWndTitle("Calculator");
    
        printf("Done");
    
    
        return 0;
    }