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LoadImageW returns NULL

DrogHead (5)
This is a simple windows application made with windows.h.
I wanted to add an ìmage to it, but the LoadImageW function returns NULL and the image doesn't show up. I added a condition that prints NULL if the value of hLogoImage is NULL, and it holds. Here's the code:

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#include <windows.h>    
#include <tchar.h>
#include <iostream>

#define FILE_MENU_NEW 1  
#define FILE_MENU_OPEN 2 
#define FILE_MENU_EXIT 3 
#define CHANGE_TITLE 4


LRESULT CALLBACK WinProc(HWND, UINT, WPARAM, LPARAM); 

void AddMenus(HWND);

void AddControls(HWND);

void LoadImages();

HMENU hmenu;

HBITMAP hLogoImage;

HWND hedit;

HWND hLogo;

int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR args, int ncmdshow) { 
	WNDCLASSW wc = {0};    						
	
	wc.hbrBackground = (HBRUSH)COLOR_WINDOW;   
	wc.hCursor = LoadCursor(NULL, IDC_ARROW);    
	wc.hInstance = hInst;			           
	wc.lpszClassName = L"WinClass";            
	wc.lpfnWndProc = WinProc;                  
	
	if(!RegisterClassW(&wc)) {  			
		return -1;			    				
	}
	 
	CreateWindowW(L"WinClass", L"Iea boi", WS_OVERLAPPEDWINDOW | WS_VISIBLE, 100, 100, 500, 500, NULL, NULL, NULL, NULL);

	MSG msg = {0};

	while( GetMessage(&msg, NULL, NULL, NULL))

	{ 
		TranslateMessage(&msg);
		DispatchMessage(&msg);		
	}

	
	return 0;
	
}

LRESULT CALLBACK WinProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {	
	switch(msg)	{
		
	case WM_COMMAND:	                                 
		
		switch(wp){	                                  	  
		case FILE_MENU_EXIT:               				  
			DestroyWindow(hwnd);						  
			break;
		case FILE_MENU_NEW:							      
			MessageBox(hwnd, "HIII", "New", MB_OK);
		        MessageBeep(MB_ICONQUESTION);               	
			break;
		case CHANGE_TITLE:								  
			wchar_t text[100];							  
			GetWindowTextW(hedit, text, 100);			  
			SetWindowTextW(hwnd, text);					  
			break;
		}
		break;
			
	case WM_CREATE:    									  
		LoadImages();									  
		AddMenus(hwnd); 								  
		AddControls(hwnd); 								  
		break;		
		
	case WM_DESTROY:	    							  
		PostQuitMessage(0); 							  
		break;
		
	default: 	                                  		  
		return DefWindowProcW(hwnd, msg, wp, lp);		
	}	
}


void AddMenus(HWND hwnd) {
	hmenu = CreateMenu();           					  
	HMENU hFileMenu = CreateMenu(); 					  
	HMENU hSubMenu = CreateMenu();  					  
	
	AppendMenu(hSubMenu, MF_STRING, NULL, "SubMenu Item");       
	
	AppendMenu(hFileMenu, MF_STRING, FILE_MENU_NEW, "New");  			 
	AppendMenu(hFileMenu, MF_POPUP, (UINT_PTR)hSubMenu, "Open SubMenu"); 
	AppendMenu(hFileMenu, MF_SEPARATOR, NULL, NULL);                     
	AppendMenu(hFileMenu, MF_STRING, FILE_MENU_EXIT, "Exit");            
	
	AppendMenu(hmenu, MF_POPUP, (UINT_PTR)hFileMenu, "File");            
	AppendMenu(hmenu, MF_STRING, NULL, "Help");                          

	SetMenu(hwnd, hmenu);                                                
}

void AddControls(HWND hwnd){
	 
	CreateWindowW(L"Static", L"Inserisci testo: ", WS_VISIBLE | WS_CHILD | WS_BORDER | SS_LEFT, 200, 100, 100, 25, hwnd, NULL, NULL, NULL);


	hedit = CreateWindowW(L"Edit", L"", WS_VISIBLE | WS_CHILD | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL , 200, 130, 100, 50, hwnd, NULL, NULL, NULL);

	//definisce un bottone, nella finestra iniziale, con la funzione CHANGE_TITLE
	CreateWindowW(L"Button", L"Change Title", WS_VISIBLE | WS_CHILD, 200, 185, 100, 25, hwnd, (HMENU)CHANGE_TITLE, NULL, NULL);

	
	hLogo = CreateWindowW(L"Static", NULL, WS_VISIBLE | WS_CHILD | SS_BITMAP, 350, 60, 100, 100, hwnd, NULL, NULL, NULL);

	
	SendMessageW(hLogo, STM_SETIMAGE, IMAGE_BITMAP, (LPARAM)hLogoImage);
}

void LoadImages(){
	
	hLogoImage = (HBITMAP)LoadImageW(NULL, L"C:/Users/Vitiello/Desktop/PEPPE/PROGRAMMAZIONE/C++/WINAPI/logo.bmp", IMAGE_BITMAP, 100, 100, LR_LOADFROMFILE);
	if(hLogoImage == NULL){
		std::cout << "NULL";
	}
}
Last edited on
Repeater (3046)
Add getlastError call after LoadImageW.

https://msdn.microsoft.com/en-gb/d852e148-985c-416f-a5a7-27b6914b45d4

You can use the value to determine what went wrong.
DrogHead (5)
I copied from docs.microsoft.com a code to get the last error:

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void ErrorExit(LPTSTR lpszFunction) 
{ 
    // Retrieve the system error message for the last-error code

    LPVOID lpMsgBuf;
    LPVOID lpDisplayBuf;
    DWORD dw = GetLastError(); 

    FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        dw,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPTSTR) &lpMsgBuf,
        0, NULL );

    // Display the error message and exit the process

    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT, 
        (lstrlen((LPCTSTR)lpMsgBuf) + lstrlen((LPCTSTR)lpszFunction) + 40) * sizeof(TCHAR)); 
    StringCchPrintf((LPTSTR)lpDisplayBuf, 
        LocalSize(lpDisplayBuf) / sizeof(TCHAR),
        TEXT("%s failed with error %d: %s"), 
        lpszFunction, dw, lpMsgBuf); 
    MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK); 

    LocalFree(lpMsgBuf);
    LocalFree(lpDisplayBuf);
    ExitProcess(dw); 
}


I added this immediately after the LoadImageW function:

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if(!GetProcessId(NULL))
        ErrorExit(LPTSTR(TEXT("GetProcessId")));


The output i got was:

GetProcessId failed with error 6: Invalid handle.
Now what should I do?
Last edited on
closed account (z05DSL3A)
I have had a bit of a play with your WinProc() so a bitmap is loaded and painted (test.bmp in c:\data\ )...
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LRESULT CALLBACK WinProc (HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {

    static HBITMAP bmpSource = NULL;
    static HDC hdcSource = NULL;

    PAINTSTRUCT ps;
    HDC hdcDestination;

    switch (msg) {

    case WM_COMMAND:

        switch (wp) {
        case FILE_MENU_EXIT:
            DestroyWindow (hwnd);
            break;
        case FILE_MENU_NEW:
            MessageBox (hwnd, L"HIII", L"New", MB_OK);
            MessageBeep (MB_ICONQUESTION);
            break;
        case CHANGE_TITLE:
            wchar_t text[100];
            GetWindowTextW (hedit, text, 100);
            SetWindowTextW (hwnd, text);
            break;
        }
        break;

    case WM_CREATE:
        bmpSource = (HBITMAP) LoadImageW (NULL, L"c:\\data\\test.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
        hdcSource = CreateCompatibleDC (GetDC (0));
        SelectObject (hdcSource, bmpSource);
        AddMenus (hwnd);
        AddControls (hwnd);
        break;

    case WM_PAINT:
        hdcDestination = BeginPaint (hwnd, &ps);
        BitBlt (hdcDestination, 0, 0, 500, 500, hdcSource, 0, 0, SRCCOPY);
        EndPaint (hwnd, &ps);
        break;
     
    case WM_DESTROY:
        PostQuitMessage (0);
        break;

    default:
        return DefWindowProcW (hwnd, msg, wp, lp);
    }
}

This is only a quick edit not best practice or designed to fit in with the rest of your code, I'll leave that to you...
DrogHead (5)
I tried your code, and I got 4 errors

C:\Users\Vitiello\AppData\Local\Temp\ccTAn9sJ.o	BASE.cpp:(.text+0x2c5): undefined reference to `__imp_CreateCompatibleDC'

C:\Users\Vitiello\AppData\Local\Temp\ccTAn9sJ.o	BASE.cpp:(.text+0x2e6): undefined reference to `__imp_SelectObject'

C:\Users\Vitiello\AppData\Local\Temp\ccTAn9sJ.o	BASE.cpp:(.text+0x371): undefined reference to `__imp_BitBlt'

C:\Users\Vitiello\Desktop\PEPPE\PROGRAMMAZIONE\C++\WINAPI\BASE\collect2.exe	[Error] ld returned 1 exit status



I followed the path inn the last error, and i don't have any file called "collect2.exe" in the BASE folder

I think the first three appeared because I need to include another library, given that the error is in the reference

For the last error, I've only seen it when i tried to compile a program that was in execution, but this isn't the case
Last edited on
closed account (z05DSL3A)
Do you link to gdi32.lib? (I think that is the one you need)

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