Use HBITMAP in dll (Logitech SDK)

Question

I'm writing a plugin for the musicplayer named MusicBee. The plugin is for the Logitech G keyboards LCD. For the Logitech G19 keyboards I will add a nice background from a bitmap file. The sdk says that I must use HBITMAP to create a background. Now I use the HBITMAP and the background ins't showing. This is the code for the background and logo on the main page of the plugin.

m_lcd.ModifyDisplay(LG_COLOR);
    background =(HBITMAP) LoadImage( NULL, L"Logitech/G19logo.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
    m_lcd.SetBackground(background);
    logo = m_lcd.AddText(LG_STATIC_TEXT, LG_BIG, DT_CENTER, LGLCD_QVGA_BMP_WIDTH);
    m_lcd.SetOrigin(logo, 0, 50);
    m_lcd.SetText(logo, _T("MusicBee"));
    m_lcd.SetTextFontColor(logo, RGB(0,0,0));
    m_lcd.Update();

The full code of my Logitech class:

//-----------------------------------------------------------------
// Logitech File
// C++ Source - Logitech.cpp - version 2012 v1.0
//-----------------------------------------------------------------

//-----------------------------------------------------------------
// Include Files
//-----------------------------------------------------------------
#include "stdafx.h"
#include "Logitech.h"

//-----------------------------------------------------------------
// Logitech methods
//-----------------------------------------------------------------


//This LogitechObject is a instance of the Logitech class for using in the thread
Logitech * Logitech::LogitechObject;

Logitech::Logitech():   stopthread(false), firstTime(true), position(0), duration(0)
{
    LogitechObject = this;
}

Logitech::~Logitech()
{
    stopthread = true;
    this->state = StatePlay::Undefined;
    timerThread.detach();
}

void CALLBACK Logitech::TimerProc(void* lpParameter, BOOLEAN TimerOrWaitFired)
{
    if(LogitechObject->m_lcd.ButtonTriggered(LG_BUTTON_4))
    {
    LogitechObject->time = 0;
    LogitechObject->m_lcd.SetProgressBarPosition(LogitechObject->progressbar, static_cast<FLOAT>(100));
    LogitechObject->m_lcd.Update();
    }
}

bool Logitech::getFirstTime()
{
    return firstTime;
}

//Initialise Logitech LCD
BOOL Logitech::OnInitDialog()
{
    HRESULT hRes = m_lcd.Initialize(_T("MusicBee"), LG_DUAL_MODE, FALSE, TRUE);

    if (hRes != S_OK)
    {
        return FALSE;
    }

    m_lcd.SetAsForeground(true);

    //Create home screen Logitech Color LCD
    if(m_lcd.IsDeviceAvailable(LG_COLOR))
    {
        m_lcd.ModifyDisplay(LG_COLOR);
        //m_lcd.SetBackground(RGB(245,245,245));
        background =(HBITMAP) LoadImage( NULL, L"Logitech/G19logo.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
        m_lcd.SetBackground(background);
        logo = m_lcd.AddText(LG_STATIC_TEXT, LG_BIG, DT_CENTER, LGLCD_QVGA_BMP_WIDTH);
        m_lcd.SetOrigin(logo, 0, 50);
        m_lcd.SetText(logo, _T("MusicBee"));
        m_lcd.SetTextFontColor(logo, RGB(0,0,0));
        m_lcd.Update();
    }

    //Create home screen Logitech Monochrome LCD
    else if(m_lcd.IsDeviceAvailable(LG_MONOCHROME))
    {
        m_lcd.ModifyDisplay(LG_MONOCHROME);
        logo = m_lcd.AddText(LG_STATIC_TEXT, LG_BIG, DT_CENTER, LGLCD_BW_BMP_WIDTH);
        m_lcd.SetOrigin(logo, 0, 5);
        m_lcd.SetText(logo, _T("MusicBee"));
        m_lcd.Update();
    }

    //Start thread
    timerThread = thread(&Logitech::startThread);

    //CreateTimerQueueTimer(NULL,NULL,&Logitech::TimerProc,this,0,1250,WT_EXECUTEDEFAULT);

    return TRUE;  // return TRUE  unless you set the focus to a control
}

//Create playing screen for Logitech Monochrome LCD
VOID Logitech::createMonochrome()
{
    m_lcd.RemovePage(0);
    m_lcd.AddNewPage();
    m_lcd.ShowPage(0);

    if (logo != 0)
    {
        delete logo;
        logo = 0;
    }

    artist = m_lcd.AddText(LG_SCROLLING_TEXT, LG_MEDIUM, DT_CENTER, LGLCD_BW_BMP_WIDTH);
    m_lcd.SetOrigin(artist, 0, 0);

    title = m_lcd.AddText(LG_SCROLLING_TEXT, LG_MEDIUM, DT_CENTER, LGLCD_BW_BMP_WIDTH);
    m_lcd.SetOrigin(title, 0, 13);

    progressbar = m_lcd.AddProgressBar(LG_FILLED);
    m_lcd.SetProgressBarSize(progressbar, 136, 5);
    m_lcd.SetOrigin(progressbar, 12, 38);

    time = m_lcd.AddText(LG_STATIC_TEXT, LG_SMALL, DT_LEFT, 80);
    m_lcd.SetOrigin(time, 12, 29);

    time1 = m_lcd.AddText(LG_STATIC_TEXT, LG_SMALL, DT_LEFT, 80);
    m_lcd.SetOrigin(time1, 125, 29);

    /*      playIcon = static_cast<HICON>(LoadImage(GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_PNG2), IMAGE_BITMAP, 16, 16, LR_MONOCHROME));
    playIconHandle = m_lcd.AddIcon(playIcon, 16, 16);
    m_lcd.SetOrigin(playIconHandle, 2, 29);*/

    firstTime = false;
    changeArtistTitle(this->artistString, this->albumString, this->titleString, this->duration, this->position);
}

//Create playing screen for Logitech Color LCD
VOID Logitech::createColor()
{
    m_lcd.RemovePage(0);
    m_lcd.AddNewPage();
    m_lcd.ShowPage(0);

    if (logo != 0)
    {
        delete logo;
        logo = 0;
    }

    //background.LoadFromResource(NULL, AfxGetInstanceHandle(), IDB_BITMAP2, _T("BMP"));
    background =(HBITMAP) LoadImage( NULL, L"Logitech/G19Background.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);

    //HBITMAP bmpBkg_ = background.GetHBITMAP();
    m_lcd.SetBackground(background);

    //m_lcd.SetBackground(RGB(184,220,240));

    artist = m_lcd.AddText(LG_SCROLLING_TEXT, LG_MEDIUM, DT_CENTER, LGLCD_QVGA_BMP_WIDTH);
    m_lcd.SetOrigin(artist, 5, 5);
    m_lcd.SetTextFontColor(artist, RGB(0,0,0));

    album = m_lcd.AddText(LG_SCROLLING_TEXT, LG_MEDIUM, DT_CENTER, LGLCD_QVGA_BMP_WIDTH);
    m_lcd.SetOrigin(album, 5, 30);
    m_lcd.SetTextFontColor(album, RGB(0,0,0));

    title = m_lcd.AddText(LG_SCROLLING_TEXT, LG_MEDIUM, DT_CENTER, LGLCD_QVGA_BMP_WIDTH);
    m_lcd.SetOrigin(title, 5, 55);
    m_lcd.SetTextFontColor(title, RGB(0,0,0));

    time = m_lcd.AddText(LG_STATIC_TEXT, LG_SMALL, DT_LEFT, 80);
    m_lcd.SetOrigin(time, 5, 80);
    m_lcd.SetTextFontColor(time, RGB(0,0,0));

    time1 = m_lcd.AddText(LG_STATIC_TEXT, LG_SMALL, DT_LEFT, 40);
    m_lcd.SetOrigin(time1, 275, 80);
    m_lcd.SetTextFontColor(time1, RGB(0,0,0));

    progressbar = m_lcd.AddProgressBar(LG_FILLED);//320�240 pixel color screen
    m_lcd.SetProgressBarSize(progressbar, 310, 20);
    m_lcd.SetProgressBarColors(progressbar, RGB(25,71,94),NULL);
    m_lcd.SetOrigin(progressbar, 5, 100);

    /*playIcon = static_cast<HICON>(LoadImage(AfxGetInstanceHandle(), MAKEINTRESOURCE(IDB_PNG1), IMAGE_ICON, 16, 16, LR_COLOR));
    playIconHandle = m_lcd.AddIcon(playIcon, 16, 16);
    m_lcd.SetOrigin(playIconHandle, 5, 29);*/

    firstTime = false;
    changeArtistTitle(this->artistString, this->albumString, this->titleString, this->duration, this->position);
}

void Logitech::startThread()
{
    while(!LogitechObject->stopthread)
    {
        this_thread::sleep_for( chrono::milliseconds(500) );

        if(!LogitechObject->stopthread && LogitechObject->progressbar != NULL)
        {
            //Update progressbar and position time on the screen after 1 second of music.
            if(LogitechObject->state == StatePlay::Playing)
            {
                this_thread::sleep_for( chrono::milliseconds(500) );
                LogitechObject->position++;
                float progresstime = ((float)LogitechObject->position / (float)LogitechObject->duration)*100;
                LogitechObject->m_lcd.SetProgressBarPosition(LogitechObject->progressbar, static_cast<FLOAT>(progresstime));
                LogitechObject->m_lcd.SetText(LogitechObject->time, LogitechObject->getTimeString(LogitechObject->position).c_str());
            }

            //If music stopped then the progressbar and time must stop immediately
            else if(LogitechObject->state == StatePlay::Stopped)
            {
                LogitechObject->position = 0;
                LogitechObject->m_lcd.SetProgressBarPosition(LogitechObject->progressbar, 0);
                LogitechObject->m_lcd.SetText(LogitechObject->time, LogitechObject->getTimeString(LogitechObject->position).c_str());
            }

            LogitechObject->m_lcd.Update();
        }
    }
}

void Logitech::changeArtistTitle(wstring artistStr, wstring albumStr, wstring titleStr, int duration, int position)
{
    this->artistString = artistStr;
    this->albumString = albumStr;
    this->titleString = titleStr;
    this->durationString = getTimeString(duration/1000);
    this->position = position;
    this->duration = duration/1000;

    if(!firstTime)
    {
        if(m_lcd.IsDeviceAvailable(LG_COLOR))
        {
            m_lcd.SetText(album, albumStr.c_str());
        }


        m_lcd.SetText(artist, artistStr.c_str());
        m_lcd.SetText(title, titleStr.c_str());
        m_lcd.SetText(time, getTimeString(position).c_str());

        string s( durationString.begin(), durationString.end() );

        if(s.size() < 5)
        {
            s = "0" + s;
        }

        wstring ws( s.begin(), s.end() );

        m_lcd.SetText(time1, ws.c_str());
        ws.clear();

        ///*playIcon = static_cast<HICON>(LoadImage(AfxGetInstanceHandle(), MAKEINTRESOURCE(IDB_PNG1), IMAGE_ICON, 16, 16, LR_COLOR));
        //playIconHandle = m_lcd.AddIcon(playIcon, 16, 16);
        //m_lcd.SetOrigin(playIconHandle, 5, 29);*/

        m_lcd.Update();

        artistStr.clear();
        albumStr.clear();
        titleStr.clear();

    }
}

//Set current playing position
void Logitech::setPosition(int pos)
{
    this->position = pos/1000;
    m_lcd.SetText(time, getTimeString(this->position).c_str());
    m_lcd.Update();
}

void Logitech::setDuration(int duration)
{
    this->duration = duration/1000;
    m_lcd.SetText(time1, getTimeString(this->duration).c_str());
    m_lcd.Update();
}

//Change play state of the current playing song
void Logitech::changeState(StatePlay state)
{
    this->state = state;

    if(state == StatePlay::Playing && firstTime)
    {
        if(m_lcd.IsDeviceAvailable(LG_COLOR))
        {
            createColor();
        }

        else if(m_lcd.IsDeviceAvailable(LG_MONOCHROME))
        {
            createMonochrome();
        }
    }
}


//Change int of time to string
wstring Logitech::getTimeString(int time)
{
    string minutes = to_string((int)time /60);
    string seconds = to_string((int)time%60);

    if(minutes.size() < 2)
    {
        minutes = "0" + minutes;
    }

    if(seconds.size() < 2)
    {
        seconds = "0" + seconds;
    }

    string timeString = minutes + ":" + seconds;

    return wstring( timeString.begin(), timeString.end() );
}

What is the problem that the background nog showing?

Answer 1

From your reply in the comments, it seems the problem is with the LoadImage call, so we can ignore the rest of the code for now. Call GetLastError right after the LoadImage call fails and see what it returns.

Only be a few things can go wrong with a LoadImage call like that:

• You could have the file name wrong. (GetLastError will return ERROR_FILE_NOT_FOUND)
• You're using a relative path, but maybe the current working directory isn't where you think it is. (GetLastError will return ERROR_FILE_NOT_FOUND or ERROR_PATH_NOT_FOUND.)
• Maybe that API doesn't work with slashes in place of backslashes.
• Maybe you don't have access to read the file. (GetLastError will return ERROR_ACCESS_DENIED or ERROR_NETWORK_ACCESS_DENIED.)
• Maybe another application has the file open without sharing. (GetLastError will return ERROR_SHARING_VIOLATION.)
• Maybe the file isn't a valid bitmap. (I'm not sure what GetLastError will return here. Perhaps something like ERROR_INVALID_PARAMETER.)
• Maybe it's a gigantic bitmap and there's not enough memory to load it. (GetLastError will return ERROR_NOT_ENOUGH_MEMORY.)

In general, when debugging, isolate the point in the code where things go bad (once you know LoadImage failed, you can stop worrying about all the code that happens after that). Then get as much information as you can (e.g., if it's a Windows API call that failed, call GetLastError and re-read the entire MSDN page for that API, use a debugger to examine the relative state at that point). From there, it will usually be pretty obvious what to do. If not, write the simplest program you can that does the same step. If it works, study the differences between your simple example and your actual code.