Question

I’ve got a problem and I’ve been trying to solve it for already a week! But I don’t get any information in the internet, which lead to the solution.

The problem’s following:
I try to write a simple Win32-GUI-Application for WIndows Embedded. I’m using Visual Studio 2008 Professional. At the beginning of the application, a connection to a server should be build. This is my code so far:

// Test.cpp : Definiert den Einstiegspunkt für die Anwendung.
//

#include "stdafx.h"
#include "Test.h"
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>


// Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")


#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"
#define MAX_LOADSTRING 100

// Globale Variablen:
HINSTANCE           g_hInst;            // Aktuelle Instanz
HWND                g_hWndMenuBar;      // Menüleistenhandle

// Vorwärtsdeklarationen der in diesem Codemodul enthaltenen Funktionen:
ATOM            MyRegisterClass(HINSTANCE, LPTSTR);
BOOL            InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPTSTR    lpCmdLine,
                   int       nCmdShow)
{
    MSG msg;

    WSADATA wsaData;
    SOCKET ConnectSocket = INVALID_SOCKET;
    struct addrinfo *result = NULL,
                    *ptr = NULL,
                    hints;
    char *sendbuf = "this is a test";
    char recvbuf[DEFAULT_BUFLEN];
    int iResult;
    int recvbuflen = DEFAULT_BUFLEN;

    // Initialize Winsock
    iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
    if (iResult != 0) {
        ;
        return 1;
    }

    ZeroMemory( &hints, sizeof(hints) );
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;

    // Resolve the server address and port
    iResult = getaddrinfo("localhost", DEFAULT_PORT, &hints, &result);
    if ( iResult != 0 ) {
        ;
        WSACleanup();
        return 1;
    }

    // Attempt to connect to an address until one succeeds
    for(ptr=result; ptr != NULL ;ptr=ptr->ai_next) {

        // Create a SOCKET for connecting to server
        ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype, 
            ptr->ai_protocol);
        if (ConnectSocket == INVALID_SOCKET) {
            ;
            WSACleanup();
            return 1;
        }

        // Connect to server.
        iResult = connect( ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
        if (iResult == SOCKET_ERROR) {
            closesocket(ConnectSocket);
            ConnectSocket = INVALID_SOCKET;
            continue;
        }
        break;
    }

    freeaddrinfo(result);

    if (ConnectSocket == INVALID_SOCKET) {
        ;
        WSACleanup();
        return 1;
    }

    // Send an initial buffer
    iResult = send( ConnectSocket, sendbuf, (int)strlen(sendbuf), 0 );
    if (iResult == SOCKET_ERROR) {
        ;
        closesocket(ConnectSocket);
        WSACleanup();
        return 1;
    }


    // shutdown the connection since no more data will be sent
    iResult = shutdown(ConnectSocket, SD_SEND);
    if (iResult == SOCKET_ERROR) {
        ;
        closesocket(ConnectSocket);
        WSACleanup();
        return 1;
    }

    // Receive until the peer closes the connection
    do {

        iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
        if ( iResult > 0 )
            ;
        else if ( iResult == 0 )
            ;
        else
            ;

    } while( iResult > 0 );

    // cleanup
    closesocket(ConnectSocket);
    WSACleanup();

    // Anwendungsinitialisierung ausführen:
    if (!InitInstance(hInstance, nCmdShow)) 
    {
        return FALSE;
    }

    HACCEL hAccelTable;
    hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_TEST));

    // Hauptmeldungsschleife:
    while (GetMessage(&msg, NULL, 0, 0)) 
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) 
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}

//
//  FUNKTION: MyRegisterClass()
//
//  ZWECK: Registriert die Fensterklasse.
//
//  KOMMENTARE:
//
ATOM MyRegisterClass(HINSTANCE hInstance, LPTSTR szWindowClass)
{
    WNDCLASS wc;

    wc.style         = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc   = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TEST));
    wc.hCursor       = 0;
    wc.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName  = 0;
    wc.lpszClassName = szWindowClass;

    return RegisterClass(&wc);
}

//
//   FUNKTION: InitInstance(HINSTANCE, int)
//
//   ZWECK: Speichert das Instanzenhandle und erstellt das Hauptfenster.
//
//   KOMMENTARE:
//
//        In dieser Funktion wird das Instanzenhandle in einer globalen Variablen gespeichert, und das
//        Hauptprogrammfenster wird erstellt und angezeigt.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
    HWND hWnd;
    TCHAR szTitle[MAX_LOADSTRING];      // Titelleistentext
    TCHAR szWindowClass[MAX_LOADSTRING];    // Klassenname des Hauptfensters

    g_hInst = hInstance; // Instanzenhandle in der globalen Variablen speichern

    // SHInitExtraControls sollte einmal während der Initialisierung der Anwendung aufgerufen werden, um alle
    // gerätespezifischen Steuerelemente wie CAPEDIT und SIPPREF zu initialisieren.
    SHInitExtraControls();

    LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING); 
    LoadString(hInstance, IDC_TEST, szWindowClass, MAX_LOADSTRING);

    //Bei bereits gestarteter Ausführung Fokus auf das Fenster verschieben und beenden
    hWnd = FindWindow(szWindowClass, szTitle);  
    if (hWnd) 
    {
        // Fokus auf das erste untergeordnete Fenster festlegen
        // "| 0x00000001" wird verwendet, um alle eigenen Fenster in den Vordergrund zu stellen und
        // zu aktivieren.
        SetForegroundWindow((HWND)((ULONG) hWnd | 0x00000001));
        return 0;
    } 

    if (!MyRegisterClass(hInstance, szWindowClass))
    {
        return FALSE;
    }

    hWnd = CreateWindow(szWindowClass, szTitle, WS_VISIBLE,
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

    if (!hWnd)
    {
        return FALSE;
    }

    // Wenn das Hauptfenster mithilfe von CW_USEDEFAULT erstellt wird, wird die Höhe der Menüleiste (falls
    // erstellt) nicht berücksichtigt. Daher wird die Größe des Fensters nach dem Erstellen angepasst,
    // sofern eine Menüleiste vorhanden ist.
    if (g_hWndMenuBar)
    {
        RECT rc;
        RECT rcMenuBar;

        GetWindowRect(hWnd, &rc);
        GetWindowRect(g_hWndMenuBar, &rcMenuBar);
        rc.bottom -= (rcMenuBar.bottom - rcMenuBar.top);

        MoveWindow(hWnd, rc.left, rc.top, rc.right-rc.left, rc.bottom-rc.top, FALSE);
    }

    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);


    return TRUE;
}

//
//  FUNKTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  ZWECK:  Verarbeitet Meldungen vom Hauptfenster.
//
//  WM_COMMAND  - Verarbeiten des Anwendungsmenüs
//  WM_PAINT    - Zeichnen des Hauptfensters
//  WM_DESTROY  - Beenden-Meldung anzeigen und zurückgeben
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;

    static SHACTIVATEINFO s_sai;

    switch (message) 
    {
        case WM_COMMAND:
            wmId    = LOWORD(wParam); 
            wmEvent = HIWORD(wParam); 
            // Menüauswahl bearbeiten:
            switch (wmId)
            {
                case IDM_HELP_ABOUT:
                    DialogBox(g_hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, About);
                    break;
                case IDM_OK:
                    SendMessage (hWnd, WM_CLOSE, 0, 0);             
                    break;
                default:
                    return DefWindowProc(hWnd, message, wParam, lParam);
            }
            break;
        case WM_CREATE:
            SHMENUBARINFO mbi;

            memset(&mbi, 0, sizeof(SHMENUBARINFO));
            mbi.cbSize     = sizeof(SHMENUBARINFO);
            mbi.hwndParent = hWnd;
            mbi.nToolBarId = IDR_MENU;
            mbi.hInstRes   = g_hInst;

            if (!SHCreateMenuBar(&mbi)) 
            {
                g_hWndMenuBar = NULL;
            }
            else
            {
                g_hWndMenuBar = mbi.hwndMB;
            }

            // Informationsstruktur für die Aktivierung der Shell initialisieren
            memset(&s_sai, 0, sizeof (s_sai));
            s_sai.cbSize = sizeof (s_sai);
            break;
        case WM_PAINT:
            hdc = BeginPaint(hWnd, &ps);

            // TODO: Hier den Zeichnungscode hinzufügen.

            EndPaint(hWnd, &ps);
            break;
        case WM_DESTROY:
            CommandBar_Destroy(g_hWndMenuBar);
            PostQuitMessage(0);
            break;

        case WM_ACTIVATE:
            // Shell über die Aktivierungsmeldung benachrichtigen
            SHHandleWMActivate(hWnd, wParam, lParam, &s_sai, FALSE);
            break;
        case WM_SETTINGCHANGE:
            SHHandleWMSettingChange(hWnd, wParam, lParam, &s_sai);
            break;

        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// Meldungshandler für Infofeld.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
        case WM_INITDIALOG:
            {
                // Erstellen Sie eine Schaltfläche "Fertig", und passen Sie die Größe an.  
                SHINITDLGINFO shidi;
                shidi.dwMask = SHIDIM_FLAGS;
                shidi.dwFlags = SHIDIF_DONEBUTTON | SHIDIF_SIPDOWN | SHIDIF_SIZEDLGFULLSCREEN | SHIDIF_EMPTYMENU;
                shidi.hDlg = hDlg;
                SHInitDialog(&shidi);
            }
            return (INT_PTR)TRUE;

        case WM_COMMAND:
            if (LOWORD(wParam) == IDOK)
            {
                EndDialog(hDlg, LOWORD(wParam));
                return TRUE;
            }
            break;

        case WM_CLOSE:
            EndDialog(hDlg, message);
            return TRUE;

    }
    return (INT_PTR)FALSE;
}

The relevant code is just copied from msdn. However, I get the following error message:

unresolved external symbol "recv" referenced in function WinMain

There ar more errors, but they are all the same. The differences are the names of the functions (e.g. shutdown, send, …)

I tried the code in a Win32-Console-Application, and it worked well!

Does anybody know, why this application doesn’t work?

Answer 1

If you look at the documentation for any of the Windows CE socket function (for example recv) you’ll see that it specifically states that the LIB file you need is ws2.lib.

That means that you need to replace this section of your code:

// Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib 
#pragma comment (lib, "Ws2_32.lib") 
#pragma comment (lib, "Mswsock.lib") 
#pragma comment (lib, "AdvApi32.lib") 

With this

#pragma comment (lib, "ws2.lib")