// SpyDemo.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <Windows.h>

#define MAX_TEXT_LEN 255

BOOL CALLBACK EnumChildProcess(HWND hwnd, LPARAM lParam)
{
    if (hwnd == NULL) {
        return FALSE;
    }
    BOOL ret;
    RECT rect;
    ret = GetWindowRect(hwnd, &rect);
    if (!ret) {
        printf("GetWindowRect hwnd=%p -> fail(%ld)\n", hwnd, GetLastError());
    }
    else {
        //printf("GetWindowRect hwnd = %p -> rect=(left=%ld, top=%ld, right=%ld, bottom=%ld)\n", hwnd, rect.left, rect.top, rect.right, rect.bottom);
        ret = PtInRect(&rect, *(POINT *)lParam);
        if (ret) {
            printf("GetWindowRect hwnd = %p -> rect=(left=%ld, top=%ld, right=%ld, bottom=%ld)\n", hwnd, rect.left, rect.top, rect.right, rect.bottom);
            //printf("PtInRect\n");

            /*
            WINUSERAPI int WINAPI GetWindowText(
            _In_ HWND hWnd,
            _Out_writes_(nMaxCount) LPTSTR lpString,    //可能是标题名或者file:///打头的文件完整路径
            _In_ int nMaxCount
            );
            如果函数成功，返回值是拷贝的字符串的字符个数，不包括中断的空字符；如果窗口无标题栏或文本，或标题栏为空，或窗口或控制的句柄无效，则返回值为零。若想获得更多错误信息，请调用GetLastError函数。
            */
            TCHAR windowText[MAX_TEXT_LEN];
            int lenRet = GetWindowText(hwnd, windowText, MAX_TEXT_LEN);
            if (lenRet == 0 && GetLastError() != 0) {
                //GetLastError()〖0〗-操作成功完成
                printf("GetWindowText hwnd=%p -> fail(%ld)\n", hwnd, GetLastError());
            }
            else {
                _tprintf(_T("GetWindowText hwnd=%p -> windowText=%s, lenRet=%d\n"), hwnd, windowText, lenRet);
            }

            /*
            WINUSERAPI int WINAPI GetClassNameW(
                _In_ HWND hWnd,
                _Out_writes_to_(nMaxCount, return) LPWSTR lpClassName,
                _In_ int nMaxCount
            );

            如果函数成功，返回值为拷贝到指定缓冲区的字符个数：如果函数失败，返回值为0。若想获得更多错误信息，请调用GetLastError函数。
            */
            TCHAR className[MAX_TEXT_LEN];
            lenRet = GetClassName(hwnd, className, MAX_TEXT_LEN);
            if (lenRet == 0) {
                printf("GetClassName hwnd=%p -> fail(%ld)\n", hwnd, GetLastError());
            }
            else {
                _tprintf(_T("GetClassName hwnd=%p -> className=%s, lenRet=%d\n"), hwnd, className, lenRet);
            }

            /*
            找出某个窗口的创建者（线程或进程），返回创建者的标志符
            哪个线程创建了这个窗口,返回的就是这个线程的id号 （进程只有一个线程的话，那么线程标志符与进程标志符就是指同一个标志符）
            WINUSERAPI DWORD WINAPI GetWindowThreadProcessId(
                _In_ HWND hWnd,
                _Out_opt_ LPDWORD lpdwProcessId //进程号的存放地址（变量地址）
            );
            返回线程号
            */
            DWORD dwProcessId;
            DWORD dwThreadId = GetWindowThreadProcessId(hwnd, &dwProcessId);
            printf("GetWindowThreadProcessId hwnd=%p -> processId=%ld, threadId=%ld\n", hwnd, dwProcessId, dwThreadId);

            /*
            WINUSERAPI UINT WINAPI GetWindowModuleFileName(
                _In_ HWND hwnd,
                _Out_writes_to_(cchFileNameMax, return) LPTSTR pszFileName, //模块完整路径
                _In_ UINT cchFileNameMax
            );
            返回值是复制到缓冲区的字符总数。
            */
            TCHAR fileName[MAX_PATH];
            lenRet = GetWindowModuleFileName(hwnd, fileName, MAX_PATH);
            if (lenRet == 0) {
                //错误码〖126〗-找不到指定的模块。
                printf("GetWindowModuleFileName hwnd=%p -> fail(%ld)\n", hwnd, GetLastError());
            } else {
                _tprintf(_T("GetWindowModuleFileName hwnd=%p -> fileName=%s\n"), hwnd, fileName);
            }

            /*
            WINUSERAPI BOOL WINAPI GetWindowInfo(
                _In_ HWND hwnd,
                _Inout_ PWINDOWINFO pwi
            );

            typedef struct tagWINDOWINFO
            {
                DWORD cbSize;
                RECT rcWindow;
                RECT rcClient;
                DWORD dwStyle;
                DWORD dwExStyle;
                DWORD dwWindowStatus;
                UINT cxWindowBorders;
                UINT cyWindowBorders;
                ATOM atomWindowType;
                WORD wCreatorVersion;
            } WINDOWINFO, *PWINDOWINFO, *LPWINDOWINFO;
            */
            WINDOWINFO windowInfo;
            windowInfo.cbSize = sizeof(WINDOWINFO);
            ret = GetWindowInfo(hwnd, &windowInfo);
            if (!ret) {
                printf("GetWindowInfo hwnd=%p -> fail(%ld)\n", hwnd, GetLastError());
            }
            else {
                printf("GetWindowInfo hwnd=%p -> dwStyle=%ld, dwExStyle=%ld, dwWindowStatus=%ld, cxWindowBorders=%d, cyWindowBorders=%d, wCreatorVersion=%d\n", hwnd, windowInfo.dwStyle, windowInfo.dwExStyle, windowInfo.dwWindowStatus, windowInfo.cxWindowBorders, windowInfo.cyWindowBorders, windowInfo.wCreatorVersion);
            }
            printf("\n");
        }
    }

    return TRUE;
}

int main()
{
    BOOL ret;
    while (true) {
        /*
        typedef struct tagPOINT
        {
            LONG  x;
            LONG  y;
        } POINT, *PPOINT, NEAR *NPPOINT, FAR *LPPOINT;
        */
        POINT point;
        ret = GetCursorPos(&point);
        if (!ret) {
            printf("GetCursorPos -> fail(%ld)\n", GetLastError());
        }
        else {
            printf("GetCursorPos -> (%ld, %ld)\n", point.x, point.y);

            //获取桌面句柄
            HWND desktopHwnd = GetDesktopWindow();

            /*
            BOOL EnumChildWindows(
                HWND hWndParent,         // handle to parent window // 父窗口句柄
                WNDENUMPROC lpEnumFunc,  // callback function // 回调函数的地址
                LPARAM lParam            // application-defined value // 你自已定义的参数
            );
            直到调用到最个一个子窗口被枚举或回调函数返回一个false，否则将一直自动枚举下去。
            */
            ret = EnumChildWindows(desktopHwnd, EnumChildProcess, (LPARAM)&point);
        }

        /*
        WINBASEAPI VOID WINAPI Sleep(
            _In_ DWORD dwMilliseconds
        );
        Sleep会将线程挂起，把CPU让给其它线程，单位是毫秒
        */
        Sleep(20000);
    }

    system("pause");
    return 0;
}

在评论里有人说道，可以用“WindowFromPoint”来实现这个功能，于是就有了下列代码。

// SpyDemo.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <Windows.h>

int main()
{
    BOOL ret;
    UINT count;
    /*
    typedef struct tagPOINT
    {
        LONG  x;
        LONG  y;
    } POINT, *PPOINT, NEAR *NPPOINT, FAR *LPPOINT;
    */
    POINT point;
    TCHAR pszFileName[MAX_PATH];
    TCHAR lpClassName[MAX_PATH];
    TCHAR windowText[MAX_PATH];
    while(true) {
        ret = GetCursorPos(&point);
        if (!ret) {
            printf("GetCursorPos -> fail(%ld)\n", GetLastError());
        } else {
            printf("GetCursorPos -> (%ld, %ld)\n", point.x, point.y);
            HWND hwnd = WindowFromPoint(point);
            if (hwnd == NULL || hwnd == INVALID_HANDLE_VALUE) {
                printf("WindowFromPoint point=(%ld, %ld) -> hwnd=%p -> fail(%ld)\n", point.x, point.y, hwnd, GetLastError());
            }
            else {
                printf("WindowFromPoint -> hwnd=%p\n", hwnd);

                /*
                检索与指定的窗口句柄关联的模块的完整路径和文件名称
                WINUSERAPI UINT WINAPI GetWindowModuleFileNameW(
                    _In_ HWND hwnd,
                    _Out_writes_to_(cchFileNameMax, return) LPWSTR pszFileName,
                    _In_ UINT cchFileNameMax
                );
                返回值是复制到缓冲区的字符总数。
                */
                count = GetWindowModuleFileName(hwnd, pszFileName, MAX_PATH);
                _tprintf(_T("GetWindowModuleFileName hwnd=%p -> count=%d, fileName=%s\n"), hwnd, count, pszFileName);

                /*
                WINUSERAPI int WINAPI GetClassName(
                    _In_ HWND hWnd,
                    _Out_writes_to_(nMaxCount, return) LPTSTR lpClassName,
                    _In_ int nMaxCount
                );
                */
                count = GetClassName(hwnd, lpClassName, MAX_PATH);
                _tprintf(_T("GetClassName hwnd=%p -> count=%d, lpClassName=%s\n"), hwnd, count, lpClassName);


                count = GetWindowText(hwnd, windowText, MAX_PATH);
                _tprintf(_T("GetWindowText hwnd=%p -> count=%d, lpClassName=%s\n"), hwnd, count, windowText);
            }

            //Screen（屏幕坐标）到Client（客户区坐标）的转换。
            ret = ScreenToClient(hwnd, &point);
            if (!ret) {
                printf("ScreenToClient hwnd=%p -> fail(%ld)\n", hwnd, GetLastError());
            }
            else {
                printf("ScreenToClient hwnd=%p -> point=(%ld, %ld)\n", hwnd, point.x, point.y);

                //返回父窗口中包含了指定点的第一个子窗口的句柄
                HWND childHwnd = ChildWindowFromPoint(hwnd, point);
                printf("ChildWindowFromPoint hwnd=%p, point=(%ld, %ld) -> childHwnd=%p\n", hwnd, point.x, point.y, childHwnd);

                count = GetClassName(hwnd, lpClassName, MAX_PATH);
                _tprintf(_T("GetClassName hwnd=%p -> count=%d, lpClassName=%s\n"), hwnd, count, lpClassName);

                count = GetWindowText(hwnd, windowText, MAX_PATH);
                _tprintf(_T("GetWindowText hwnd=%p -> count=%d, lpClassName=%s\n"), hwnd, count, windowText);
            }
        }
        Sleep(5000);
    }
    return 0;
}

但是有一个问题：
　　为什么 GetWindowModuleFileName 虽然句柄每次都不一样，但是获取到的模块文件路径每次都是一样的当前的路径。
　　希望有大神能帮我解答一下，感激不尽。