how to read text file and show it on edit control in win 32 unicode character set? - visual-c++

Question

i have been making a program to read the text from a text file on a button click and show it on the edit control. when the button is clicked, the dialog box opens to select the text file and clicking on ok, it should display on edit control but i am not getting the text in proper format.
this is the output : output image from visual studio
#include <windows.h>
const wchar_t g_szClassName[] = { L"myWindowClass" };
#define IDC_MAIN_EDIT 101
#define IDC_MAIN_BUTTON 102
#define IDC_MAIN_BUTTON1 103
BOOL LoadTextFileToEdit(HWND hEdit, LPTSTR 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)
{
wchar_t* pszFileText;
pszFileText = (wchar_t*)GlobalAlloc(GPTR, dwFileSize + 1);
if (pszFileText != NULL)
{
DWORD dwRead;
if (ReadFile(hFile, (LPVOID)pszFileText, dwFileSize, &dwRead, NULL))
{
pszFileText[dwFileSize] = 0 ; // Add null terminator
if (SetWindowText(hEdit, (LPCWSTR)pszFileText))
bSuccess = TRUE; // It worked!
}
GlobalFree(pszFileText);
}
}
CloseHandle(hFile);
}
return bSuccess;
}
// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_CREATE:
{
HFONT hfont;
HWND hedit,button,btnsave;
hedit = CreateWindowEx(WS_EX_CLIENTEDGE, L"EDIT", L"My Own Window", WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL | ES_AUTOVSCROLL | ES_MULTILINE
, CW_USEDEFAULT, CW_USEDEFAULT, 100, 100, hwnd, (HMENU)IDC_MAIN_EDIT, GetModuleHandle(NULL), NULL);
button = CreateWindowEx(WS_EX_CLIENTEDGE, L"BUTTON", L"Open File", WS_CHILD | WS_VISIBLE|WS_BORDER|WS_TABSTOP
,CW_USEDEFAULT, CW_USEDEFAULT, 50, 20, hwnd, (HMENU)IDC_MAIN_BUTTON, GetModuleHandle(NULL), NULL);
btnsave = CreateWindowEx(WS_EX_CLIENTEDGE, L"BUTTON", L"Save File", WS_CHILD | WS_VISIBLE | WS_EX_STATICEDGE|WS_TABSTOP
, CW_USEDEFAULT, CW_USEDEFAULT, 50, 20, hwnd, (HMENU)IDC_MAIN_BUTTON1, GetModuleHandle(NULL), NULL);
if (hedit == NULL)
{
MessageBox(NULL, L"Could not create edit box", L"Error!", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
hfont = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
SendMessage(hedit, WM_SETFONT, (WPARAM)hfont, MAKELPARAM(FALSE, 0));
//SetWindowText(button, L"Open File");
//SetWindowText(btnsave, L"Save File");
}
break;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDC_MAIN_BUTTON:
{
OPENFILENAME ofn;
wchar_t szFileName[MAX_PATH] = L"";
ZeroMemory(&ofn, sizeof(ofn));
ofn.lStructSize = sizeof(ofn); // SEE NOTE BELOW
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))
{
// Do something usefull with the filename stored in szFileName
HWND hedit;
hedit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
LoadTextFileToEdit(hedit, szFileName);
}
}
break;
case IDC_MAIN_BUTTON1:
{
OPENFILENAME ofn;
wchar_t szFileName[MAX_PATH] = L"";
ZeroMemory(&ofn, sizeof(ofn));
ofn.lStructSize = sizeof(ofn); // SEE NOTE BELOW
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_PATHMUSTEXIST | OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT;
ofn.lpstrDefExt = L"txt";
if (GetOpenFileName(&ofn))
{
// Do something usefull with the filename stored in szFileName
HWND hedit;
hedit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
}
}
break;
default:
break;
}
break;
case WM_SIZE:
{
HWND hEdit,button,btnsave;
RECT rcClient;
GetClientRect(hwnd, &rcClient);
hEdit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
button = GetDlgItem(hwnd, IDC_MAIN_BUTTON);
btnsave = GetDlgItem(hwnd, IDC_MAIN_BUTTON1);
SetWindowPos(hEdit, NULL, 0, 0, rcClient.right, rcClient.bottom-120, SWP_NOZORDER);
SetWindowPos(button, NULL, rcClient.right-200, rcClient.bottom-30, 70, 30, SWP_NOZORDER);
SetWindowPos(btnsave, NULL, rcClient.right - 100, rcClient.bottom - 30, 70, 30, SWP_NOZORDER);
}
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
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;
//step 1: registering the window class
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 = NULL;
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;
}
//step 2: Creating the Window
hwnd = CreateWindowEx(WS_EX_CLIENTEDGE,
g_szClassName, L"The title of my window", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 300,
NULL, NULL, hinstance, NULL);
if (hwnd == NULL)
{
MessageBox(NULL, L"Window Registration failed", L"Error!", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
//Step-3: the message loop
while (GetMessage(&msg, NULL, 0, 0)>0)
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}

Answer 1

i got the answer to my question. Actually in unicode wide string a character is of 2 bytes so we need to allocate twice the memory. so replace :
pszFileText = (wchar_t*)GlobalAlloc(GPTR, dwFileSize + 1);
with
pszFileText = (wchar_t*)GlobalAlloc(GPTR, 2*(dwFileSize + 1));
and
if (ReadFile(hFile, (LPVOID)pszFileText, dwFileSize, &dwRead, NULL))
with
if (ReadFile(hFile, (LPVOID)pszFileText, 2*(dwFileSize+1), &dwRead, NULL))