Enumerating programs installed

[James]

I'm looking into writing a Win32 API app that lists programs that are installed on a local machine. I have found that a method of doing this would be going through the registry and seeing the uninstall strings to see what programs are on the machine.

Now the issue, found a piece of code that works fine if I compile in a console app, but for some reason when I put it into my win32 api project, it prints NULL and I'm not sure why.

Any ideas?

Here is the source

// testx.cpp : Defines the entry point for the application.
//
#include "stdafx.h"
#include "testx.h"
#include <stdio.h>
#include <winreg.h>

// Global Variables:
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);

void CenterWindow(HWND hwnd) 
{
    RECT rc;

    GetWindowRect(hwnd,&rc);

    int nWidth = rc.right - rc.left;
    int nHeight = rc.bottom - rc.top;

    int X = ((int) GetSystemMetrics(SM_CXFULLSCREEN) - nWidth) /2;       // center window horizontally
    int Y = ((int) GetSystemMetrics(SM_CYFULLSCREEN) - nHeight) /2;      // and vertically

    MoveWindow(hwnd,X,Y,nWidth,nHeight,TRUE);
}

bool EnumInstalledSoftware(void)
{
    HKEY hUninstKey = NULL;
    HKEY hAppKey = NULL;
    WCHAR sAppKeyName[1024];
    WCHAR sSubKey[1024];
    WCHAR sDisplayName[1024];
    WCHAR *sRoot = L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
    long lResult = ERROR_SUCCESS;
    DWORD dwType = KEY_ALL_ACCESS;
    DWORD dwBufferSize = 0;

    //Open the "Uninstall" key.
    if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, (LPCSTR)sRoot, 0, KEY_READ, &hUninstKey) != ERROR_SUCCESS)
    {
        return false;
    }

    for(DWORD dwIndex = 0; lResult == ERROR_SUCCESS; dwIndex++)
    {
        //Enumerate all sub keys...
        dwBufferSize = sizeof(sAppKeyName);
        if((lResult = RegEnumKeyEx(hUninstKey, dwIndex, (LPSTR)sAppKeyName, &dwBufferSize, NULL, NULL, NULL, NULL)) == ERROR_SUCCESS)
        {
            //Open the sub key.
            wsprintf((LPSTR)sSubKey, "%s\\%s", sRoot, sAppKeyName);
            if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, (LPCSTR)sSubKey, 0, KEY_READ, &hAppKey) != ERROR_SUCCESS)
            {
                RegCloseKey(hAppKey);
                RegCloseKey(hUninstKey);
                return false;
            }

            //Get the display name value from the application's sub key.
            dwBufferSize = sizeof(sDisplayName);
            if(RegQueryValueEx(hAppKey, "DisplayName", NULL, &dwType, (unsigned char*)sDisplayName, &dwBufferSize) == ERROR_SUCCESS)
            {
                wsprintf("%s\n", (LPCSTR)sDisplayName);
            }
            else
            {
                //Display name value doe not exist, this application was probably uninstalled.
            }

            RegCloseKey(hAppKey);
        }
    }

    RegCloseKey(hUninstKey);

    return true;
}

int APIENTRY WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow )
{
    char szBuffer[1024];
    sprintf_s(szBuffer, "%s\n", EnumInstalledSoftware());

    //This checks if the process is already running so you don't have multiple instances running.
    HANDLE handle = CreateMutex(NULL, true, "testx");
    if(GetLastError() != ERROR_SUCCESS)
    {
        MessageBox(0, "Process is already running", "Warning", MB_ICONWARNING);
        return false;
    }

    char szWindowClass[] = "test_WindowClass";
    MSG msg;

    WNDCLASSEX wcex        = {0};
    wcex.cbSize            = sizeof(WNDCLASSEX);
    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.hInstance      = hInstance;
    wcex.hCursor        = LoadCursor( NULL, IDC_ARROW );
    wcex.hbrBackground    = CreateSolidBrush(RGB(255, 255, 255)); 
    wcex.lpszClassName  = szWindowClass;
    RegisterClassEx( &wcex );

    HWND hWnd = CreateWindowEx( 0, szWindowClass, "Test", WS_OVERLAPPED | WS_CLIPCHILDREN | WS_CAPTION | WS_SYSMENU, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL );
    HWND hwndLabel = CreateWindow(
                        TEXT("STATIC"),
                        szBuffer,//TEXT("Label 1"), 
                        WS_CHILD | WS_VISIBLE | SS_LEFT,  /*Styles (continued)*/
                        0,                                /*X co-ordinates*/
                        0,                                /*Y co-ordinates*/
                        1024,                               /*Width*/
                        768,                               /*Height*/
                        hWnd, (HMENU) ID_MYSTATIC, hInstance, NULL);

    if(!hWnd)
    {
        return FALSE;
    }

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

    while(GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage( &msg );
        DispatchMessage( &msg );
    }

    return (int) msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;

    switch (message)
    {
        case WM_COMMAND:
        {
            wmId    = LOWORD(wParam);
            wmEvent = HIWORD(wParam);
                
            // Parse the menu selections:
            switch (wmId)
            {
                case IDM_EXIT:
                    DestroyWindow(hWnd);
                break;
            
                default:
                    return DefWindowProc(hWnd, message, wParam, lParam);
            }

            break;
        }

        case WM_PAINT:
        {
            hdc = BeginPaint(hWnd, &ps);
            
            // TODO: Add any drawing code here...

            EndPaint(hWnd, &ps);
            break;
        }

        case WM_KEYDOWN:
        {
             if (wParam == VK_ESCAPE) 
             {
                 int ret = MessageBox(NULL, TEXT("Are you sure to quit?"), TEXT("Message"), MB_OKCANCEL);
                 
                 if ( ret == IDOK) 
                 {
                     SendMessage(hWnd, WM_CLOSE, 0, 0);
                 }
             }
             break;
        }

        case WM_DESTROY:
            PostQuitMessage(0);
        break;

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

[Elgan]

then its probably a problem with the printing and format, how youre pritning it.