GlobalFree - Heap block at....

Witam
Pisze w WinAPI coś podobnego do Notatnika. Appka jest wzorowana na przykładzie z tutoriala znalezionego w sieci. Jednak on jest w wersji ANSI. Ja korzystam z VS 2013, więc tam jest UNICODE. Próbuje go przekonwertować na UNICODE. Niby aplikacja działa, ale kiedy otwieram lub zapisuje plik to się wywala. Jeśli zapisywany plik jest pusty to działa poprawnie. Crash jest w funkcji GlobalFree. Skorzystałem z GetLastError i kod błędu to 0x6 - ERROR_INVALID_HANDLE. Domyślam się więc, że podałem zły uchwyt do bloku pamięci na Heap. Słabo sie znam C i gubie się w tych konwersjach typów zmiennych.

Takie coś widze w komunikatach debuggera VS:
HEAP[TextEd.exe]: Heap block at 04B41E50 modified at 04B41E5F past requested size of 7
TextEd.exe has triggered a breakpoint.

Nie wiem czy ide dobrym tropem. Szarpie sie z tym jakiś czas, ale kończy mi sie repertuar pomysłów co z tym więcej zrobić. Będę wdzieczy za pomoc.

Tu jest kod:

#include "stdafx.h"
#include <windows.h>
#include <commctrl.h>
#include <commdlg.h>
#include "resource.h"


#define IDR_MAINMENU                    102
#define ID_FILE_EXIT                    40001
#define ID_FILE_OPEN                    40002
#define ID_FILE_SAVEAS                  40003
#define ID_FILE_NEW                     40004

const wchar_t g_szClassName[] = L"myWindowClass";

#define IDC_MAIN_EDIT 101
#define IDC_MAIN_TOOL 102
#define IDC_MAIN_STATUS 103


BOOL LoadTextFileToEdit(HWND hEdit, LPCWSTR pszFileName)
{
HANDLE hFile;
BOOL bSuccess = FALSE;

hFile = CreateFile(pszFileName, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, 0, NULL);
if (hFile != INVALID_HANDLE_VALUE)
{
DWORD dwFileSize;

dwFileSize = GetFileSize(hFile, NULL);
if (dwFileSize != 0xFFFFFFFF)
{
LPWSTR pszFileText;

pszFileText = (LPWSTR)GlobalAlloc(GPTR, dwFileSize + 1);
if (pszFileText != NULL)
{
DWORD dwRead;

if (ReadFile(hFile, pszFileText, dwFileSize, &dwRead, NULL))
{
pszFileText[dwFileSize] = 0; // Add null terminator
if (SetWindowText(hEdit, pszFileText))
bSuccess = TRUE; // It worked!
}
GlobalFree(pszFileText);
int Error = GetLastError();
}
}
CloseHandle(hFile);
}
return bSuccess;
}

BOOL SaveTextFileFromEdit(HWND hEdit, LPCWSTR pszFileName)
{
HANDLE hFile;
BOOL bSuccess = FALSE;

hFile = CreateFile(pszFileName, GENERIC_WRITE, 0, NULL,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (hFile != INVALID_HANDLE_VALUE)
{
DWORD dwTextLength;

dwTextLength = GetWindowTextLength(hEdit);
// No need to bother if there's no text.
if (dwTextLength > 0)
{
LPWSTR pszText;
DWORD dwBufferSize = dwTextLength + 1;

pszText = (LPWSTR)GlobalAlloc(GPTR, dwBufferSize+1);
if (pszText != NULL)
{
if (GetWindowText(hEdit, pszText, dwBufferSize))
{
DWORD dwWritten;

if (WriteFile(hFile, pszText, dwTextLength, &dwWritten, NULL))
bSuccess = TRUE;
}
GlobalFree(pszText);
int Error = 0;
Error = GetLastError();
Error = Error;

}
}
CloseHandle(hFile);
}
return bSuccess;
}

void DoFileOpen(HWND hwnd)
{
OPENFILENAME ofn;
wchar_t szFileName[MAX_PATH] = L"";

ZeroMemory(&ofn, sizeof(ofn));

ofn.lStructSize = sizeof(ofn);
ofn.hwndOwner = hwnd;
ofn.lpstrFilter = L"Text Files (*.txt)\0*.txt\0All Files (*.*)\0*.*\0";
ofn.lpstrFile = szFileName;
ofn.nMaxFile = MAX_PATH;
ofn.Flags = OFN_EXPLORER | OFN_FILEMUSTEXIST | OFN_HIDEREADONLY;
ofn.lpstrDefExt = L"txt";

if (GetOpenFileName(&ofn))
{
HWND hEdit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
if (LoadTextFileToEdit(hEdit, szFileName))
{
SendDlgItemMessage(hwnd, IDC_MAIN_STATUS, SB_SETTEXT, 0, (LPARAM)L"Opened...");
SendDlgItemMessage(hwnd, IDC_MAIN_STATUS, SB_SETTEXT, 1, (LPARAM)szFileName);
}
}
}

void DoFileSave(HWND hwnd)
{
OPENFILENAME ofn;
wchar_t szFileName[MAX_PATH] = L"";

ZeroMemory(&ofn, sizeof(ofn));

ofn.lStructSize = sizeof(ofn);
ofn.hwndOwner = hwnd;
ofn.lpstrFilter = L"Text Files (*.txt)\0*.txt\0All Files (*.*)\0*.*\0";
ofn.lpstrFile = szFileName;
ofn.nMaxFile = MAX_PATH;
ofn.lpstrDefExt = L"txt";
ofn.Flags = OFN_EXPLORER | OFN_PATHMUSTEXIST | OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT;

if (GetSaveFileName(&ofn))
{
HWND hEdit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
if (SaveTextFileFromEdit(hEdit, szFileName))
{
SendDlgItemMessage(hwnd, IDC_MAIN_STATUS, SB_SETTEXT, 0, (LPARAM)L"Saved...");
SendDlgItemMessage(hwnd, IDC_MAIN_STATUS, SB_SETTEXT, 1, (LPARAM)szFileName);
}
}
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_CREATE:
{
HFONT hfDefault;
HWND hEdit;

HWND hTool;
TBBUTTON tbb[3];
TBADDBITMAP tbab;

HWND hStatus;
int statwidths[] = { 100, -1 };

// Create Edit Control

hEdit = CreateWindowEx(WS_EX_CLIENTEDGE, L"EDIT", L"",
WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL | ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL,
0, 0, 100, 100, hwnd, (HMENU)IDC_MAIN_EDIT, GetModuleHandle(NULL), NULL);
if (hEdit == NULL)
MessageBox(hwnd, L"Could not create edit box.", L"Error", MB_OK | MB_ICONERROR);

hfDefault = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
SendMessage(hEdit, WM_SETFONT, (WPARAM)hfDefault, MAKELPARAM(FALSE, 0));

// Create Toolbar

hTool = CreateWindowEx(0, TOOLBARCLASSNAME, NULL, WS_CHILD | WS_VISIBLE, 0, 0, 0, 0,
hwnd, (HMENU)IDC_MAIN_TOOL, GetModuleHandle(NULL), NULL);
if (hTool == NULL)
MessageBox(hwnd, L"Could not create tool bar.", L"Error", MB_OK | MB_ICONERROR);

// Send the TB_BUTTONSTRUCTSIZE message, which is required for
// backward compatibility.
SendMessage(hTool, TB_BUTTONSTRUCTSIZE, (WPARAM)sizeof(TBBUTTON), 0);

tbab.hInst = HINST_COMMCTRL;
tbab.nID = IDB_STD_SMALL_COLOR;
SendMessage(hTool, TB_ADDBITMAP, 0, (LPARAM)&tbab);

ZeroMemory(tbb, sizeof(tbb));
tbb[0].iBitmap = STD_FILENEW;
tbb[0].fsState = TBSTATE_ENABLED;
tbb[0].fsStyle = TBSTYLE_BUTTON;
tbb[0].idCommand = ID_FILE_NEW;

tbb[1].iBitmap = STD_FILEOPEN;
tbb[1].fsState = TBSTATE_ENABLED;
tbb[1].fsStyle = TBSTYLE_BUTTON;
tbb[1].idCommand = ID_FILE_OPEN;

tbb[2].iBitmap = STD_FILESAVE;
tbb[2].fsState = TBSTATE_ENABLED;
tbb[2].fsStyle = TBSTYLE_BUTTON;
tbb[2].idCommand = ID_FILE_SAVEAS;

SendMessage(hTool, TB_ADDBUTTONS, sizeof(tbb) / sizeof(TBBUTTON), (LPARAM)&tbb);

// Create Status bar

hStatus = CreateWindowEx(0, STATUSCLASSNAME, NULL,
WS_CHILD | WS_VISIBLE | SBARS_SIZEGRIP, 0, 0, 0, 0,
hwnd, (HMENU)IDC_MAIN_STATUS, GetModuleHandle(NULL), NULL);

SendMessage(hStatus, SB_SETPARTS, sizeof(statwidths) / sizeof(int), (LPARAM)statwidths);
SendMessage(hStatus, SB_SETTEXT, 0, (LPARAM)L"Hi there :)");
}
break;
case WM_SIZE:
{
HWND hTool;
RECT rcTool;
int iToolHeight;

HWND hStatus;
RECT rcStatus;
int iStatusHeight;

HWND hEdit;
int iEditHeight;
RECT rcClient;

// Size toolbar and get height

hTool = GetDlgItem(hwnd, IDC_MAIN_TOOL);
SendMessage(hTool, TB_AUTOSIZE, 0, 0);

GetWindowRect(hTool, &rcTool);
iToolHeight = rcTool.bottom - rcTool.top;

// Size status bar and get height

hStatus = GetDlgItem(hwnd, IDC_MAIN_STATUS);
SendMessage(hStatus, WM_SIZE, 0, 0);

GetWindowRect(hStatus, &rcStatus);
iStatusHeight = rcStatus.bottom - rcStatus.top;

// Calculate remaining height and size edit

GetClientRect(hwnd, &rcClient);

iEditHeight = rcClient.bottom - iToolHeight - iStatusHeight;

hEdit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
SetWindowPos(hEdit, NULL, 0, iToolHeight, rcClient.right, iEditHeight, SWP_NOZORDER);
}
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case ID_FILE_EXIT:
PostMessage(hwnd, WM_CLOSE, 0, 0);
break;
case ID_FILE_NEW:
SetDlgItemText(hwnd, IDC_MAIN_EDIT, L"");
break;
case ID_FILE_OPEN:
DoFileOpen(hwnd);
break;
case ID_FILE_SAVEAS:
DoFileSave(hwnd);
break;
}
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;

//InitCommonControls();

wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.lpszMenuName = MAKEINTRESOURCE(IDR_MAINMENU);
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

if (!RegisterClassEx(&wc))
{
MessageBox(NULL, L"Window Registration Failed!", L"Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}

hwnd = CreateWindowEx(
0,
g_szClassName,
L"TextEd",
WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN,
CW_USEDEFAULT, CW_USEDEFAULT, 480, 320,
NULL, NULL, hInstance, NULL);

if (hwnd == NULL)
{
MessageBox(NULL, L"Window Creation Failed!", L"Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}

ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);

while (GetMessage(&Msg, NULL, 0, 0) > 0)
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
return Msg.wParam;
}


standard pozdrawiam...

wg mnie w funkcji LoadTextFileToEdit, zamiast
pszFileText = (LPWSTR)GlobalAlloc(GPTR, dwFileSize + 1);
powinno być
pszFileText = (LPWSTR)GlobalAlloc(GPTR, dwFileSize + sizeof(wchar_t));

natomiast w SaveTextFileFromEdit zmień:
DWORD dwBufferSize = dwTextLength + 1;
na
DWORD dwBufferSize = (dwTextLength + 1) * sizeof(wchar_t);

pszText = (LPWSTR)GlobalAlloc(GPTR, dwBufferSize+1);
na
pszText = (LPWSTR)GlobalAlloc(GPTR, dwBufferSize);

if (GetWindowText(hEdit, pszText, dwBufferSize))
na
if (GetWindowText(hEdit, pszText, dwBufferSize / sizeof(wchar_t)))
albo na
if (GetWindowText(hEdit, pszText, dwTextLength + 1))

if (WriteFile(hFile, pszText, dwTextLength, &dwWritten, NULL))
na
if (WriteFile(hFile, pszText, dwTextLength * sizeof(wchar_t), &dwWritten, NULL))

pewnie są i inne błędy... a najpoważniejszym błędem jest oczywiście notacja węgierska.

Tak, dwa bajty na znak - prawda.
Teraz działa lepiej tzn. zapisywanie działa, ale odczytywanie nie działa.