C++ Windows 下 根据进程名获取进程ID 以及该进程下所有窗口的句柄

#include <windows.h>
#include <stdint.h>
#include <tlhelp32.h>
#include <stdio.h>
#include <iostream>
#include <vector>

typedef struct EnumHWndsArg
{
    std::vector<HWND> *vecHWnds;
    DWORD dwProcessId;
}EnumHWndsArg, *LPEnumHWndsArg;

HANDLE GetProcessHandleByID(int nID)//通过进程ID获取进程句柄
{
    return OpenProcess(PROCESS_ALL_ACCESS, FALSE, nID);
}

DWORD GetProcessIDByName(const char* pName)
{
    HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, );
    if (INVALID_HANDLE_VALUE == hSnapshot) {
        return NULL;
    }
    PROCESSENTRY32 pe = { sizeof(pe) };
    for (BOOL ret = Process32First(hSnapshot, &pe); ret; ret = Process32Next(hSnapshot, &pe)) {
        if (strcmp(pe.szExeFile, pName) == ) {
            CloseHandle(hSnapshot);
            return pe.th32ProcessID;
        }
        //printf("%-6d %s\n", pe.th32ProcessID, pe.szExeFile);
    }
    CloseHandle(hSnapshot);
    return ;
}

BOOL CALLBACK lpEnumFunc(HWND hwnd, LPARAM lParam)
{
    EnumHWndsArg *pArg = (LPEnumHWndsArg)lParam;
    DWORD  processId;
    GetWindowThreadProcessId(hwnd, &processId);
    if (processId == pArg->dwProcessId)
    {
        pArg->vecHWnds->push_back(hwnd);
        //printf("%p\n", hwnd);
    }
    return TRUE;
}

void GetHWndsByProcessID(DWORD processID, std::vector<HWND> &vecHWnds)
{
    EnumHWndsArg wi;
    wi.dwProcessId = processID;
    wi.vecHWnds = &vecHWnds;
    EnumWindows(lpEnumFunc, (LPARAM)&wi);
}

int32_t main()
{
    DWORD pid = GetProcessIDByName("notepad++.exe");
    printf("pid = %u\n", pid);
    if (pid != )
    {
        std::vector<HWND> vecHWnds;
        GetHWndsByProcessID(pid, vecHWnds);
        printf("vecHWnds.size() = %u\n", vecHWnds.size());
        for (const HWND &h : vecHWnds)
        {
            HWND parent = GetParent(h);
            if (parent == NULL)
            {
                printf("%p --->Main Wnd\n", h);
            }
            else
            {
                printf("%p %p\n", h, parent);
            }
        }
    }
    getchar();
    return S_OK;
}