// -------------------------------------------------------
//
// Demonstration der Anwendung einer ProgressBar
// Bitte einen beliebigen Dateinamen in das Editfeld eingeben
// Z.B. "C:\\Command.com"
// Nach Mausklick auf "OK" geht es dann los.
//
// -------------------------------------------------------

#include 
#include 
#pragma comment(lib,"Comctl32.lib")

#define ID_BN_OK 1
#define ID_BN_Cancel 2
#define ID_EDIT 3

LRESULT CALLBACK WndProcedure(HWND, UINT, WPARAM, LPARAM);
BOOL readFile(HWND, LPSTR);

HINSTANCE hInst;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevInstance,
                   PSTR szCmdLine, int iCmdShow)
{
   static TCHAR szAppName[] = TEXT("Progress Bar");
   MSG msg;
   HWND hwnd;
   WNDCLASS wndclass;
   hInst = hInstance;

   wndclass.style = CS_HREDRAW | CS_VREDRAW;
   wndclass.lpfnWndProc = WndProcedure;
   wndclass.cbClsExtra = 0;
   wndclass.cbWndExtra = 0;
   wndclass.hInstance = hInstance;
   wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
   wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
   wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
   wndclass.lpszClassName = szAppName;
   wndclass.lpszMenuName = NULL;

   if(!RegisterClass(&wndclass))
   {
      MessageBox(NULL, TEXT("Error: Unable to execute"), szAppName, MB_ICONERROR);
   }

   hwnd = CreateWindow(szAppName, TEXT("PBar in Action"), WS_OVERLAPPEDWINDOW,
                     CW_USEDEFAULT, CW_USEDEFAULT,
                     700, 100,
                     NULL, NULL, hInstance, NULL);

   ShowWindow(hwnd, iCmdShow);
   UpdateWindow(hwnd);

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

   return msg.lParam;
}
   LRESULT CALLBACK WndProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
   static HWND hwndBN_OK, hwndBN_Cancel, hwndEdit, hwndPB;
   static int cxChar, cyChar;

   switch(message)
   {
      case WM_CREATE:
         cxChar = LOWORD(GetDialogBaseUnits());
         cyChar = HIWORD(GetDialogBaseUnits());
         hwndBN_OK = CreateWindow(TEXT("Button"),
                           "OK",
                           WS_CHILD | WS_VISIBLE |BS_PUSHBUTTON,
                           cxChar, cyChar,
                           20 * cxChar, 7 * cyChar / 4,
                           hwnd,
                           (HMENU) ID_BN_OK,
                           ((LPCREATESTRUCT) lParam)->hInstance,
                           NULL);

         hwndEdit = CreateWindow(TEXT("Edit"),
                       NULL,
                       WS_CHILD | WS_VISIBLE |
                       WS_BORDER | ES_LEFT,
                       22 * cxChar, cyChar,
                       40 * cxChar, 7 * cyChar / 4,
                       hwnd,
                       (HMENU) ID_BN_Cancel,
                       ((LPCREATESTRUCT) lParam)->hInstance,
                       NULL);

         SetWindowText (hwndEdit, "C:\\\\Command.com");

         hwndBN_OK = CreateWindow(TEXT("Button"),
                        "Cancel",
                        WS_CHILD | WS_VISIBLE |
                        BS_PUSHBUTTON,
                        64 * cxChar, cyChar,
                        20 * cxChar, 7 * cyChar / 4,
                        hwnd,
                        (HMENU) ID_BN_Cancel,
                        ((LPCREATESTRUCT) lParam)->hInstance,
                        NULL);

         // ProgressBar erzeugen

         InitCommonControls();

         hwndPB = CreateWindowEx(0, PROGRESS_CLASS,
                     "", WS_CHILD | WS_VISIBLE,
                     cxChar, 3 * cyChar,
                     20 * cxChar, cyChar,
                     hwnd, NULL,
                     hInst, NULL);
         return 0;

      case WM_SETFOCUS:
         SetFocus(hwndEdit);
         return 0;

      case WM_COMMAND:
         if(LOWORD(wParam) == ID_BN_OK && HIWORD(wParam) == BN_CLICKED)
         {
            char szText[100];
            GetWindowText(hwndEdit, szText, 100);
            readFile(hwndPB, szText);
         }

         if(LOWORD(wParam) == ID_BN_Cancel && HIWORD(wParam) == BN_CLICKED)
         {
            PostQuitMessage(0);
         }
         return 0;

      case WM_DESTROY:
         PostQuitMessage(0);
         return 0;
   }

   return DefWindowProc(hwnd, message, wParam, lParam);
}

BOOL readFile(HWND hwndParent, LPSTR lpszFileName)
{
   HANDLE hFile;
   DWORD cb;

   DWORD dwRead = 0;
   char chRead;
   int i = 0;

   hFile = CreateFile(lpszFileName, GENERIC_READ,
              FILE_SHARE_READ, (LPSECURITY_ATTRIBUTES)
              NULL, OPEN_EXISTING,
              FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL);

   if (hFile == (HANDLE) INVALID_HANDLE_VALUE)
      return FALSE;

   cb = GetFileSize(hFile, (LPDWORD) NULL);

   // Schrittläge einstellen

   SendMessage(hwndParent, PBM_SETRANGE, 0, MAKELPARAM (0, 100)); 
   SendMessage(hwndParent, PBM_SETSTEP, (WPARAM) 10, 0); // mit jedem Schritt 10% weiter

   do {
      ReadFile(hFile, &chRead, 1, &dwRead, (LPOVERLAPPED) NULL);
      i++;
      if (i >= cb / 10) // Haben wir wieder 1/10tel der Dateigröße eingelesen?

      {
         i = 0;
         SendMessage(hwndParent, PBM_STEPIT, 0, 0); // Befehl um einen Schritt zu machen
      }
   } while (dwRead);

   CloseHandle((HANDLE) hFile);
   return TRUE;
}