请有空的人给我解释一下windows应用程序
/*-----------------------------------------SEQDISP.C -- Sequential Display of DIBs
(c) Charles Petzold, 1998
-----------------------------------------*/
//我的MSDN还没下载出来麻烦热心的网友给我解释一下程序的意思
#include <windows.h>
#include "resource.h"
//麻烦热心的高手告诉我一下这都是什么意思
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;//请问高手这是什么意思
TCHAR szAppName[] = TEXT ("SeqDisp") ;//这又是什么意思
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)//我知道这是主函数类似c语言中的main
{
HACCEL hAccel ;//这里不明白麻烦高手指点一下
HWND hwnd ;//这是？？？？？
MSG msg ;
WNDCLASS wndclass ;//这些都是什么意思
//这下面的是什么有什么用？？？？
wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
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.lpszMenuName = szAppName ;
wndclass.lpszClassName = szAppName ;
if (!RegisterClass (&wndclass))//我知道这是判断可是不不知道是判断什么？？？？？
{
MessageBox (NULL, TEXT ("This program requires Windows NT!"),这个我知道是提示用的信息
szAppName, MB_ICONERROR) ;//这是？？？
return 0 ;//我知道这是返回值
}
hwnd = CreateWindow (szAppName, TEXT ("DIB Sequential Display"),//这是做什么用的？？？？
//一下都是什么？？？
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;
hAccel = LoadAccelerators (hInstance, szAppName) ;
while (GetMessage (&msg, NULL, 0, 0))
{
if (!TranslateAccelerator (hwnd, hAccel, &msg))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
}
return msg.wParam ;
}
//一下都是什么？？？？
LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static BITMAPINFO * pbmi ;
static BYTE * pBits ;
static int cxDib, cyDib, cBits ;
static OPENFILENAME ofn ;
static TCHAR szFileName [MAX_PATH], szTitleName [MAX_PATH] ;
static TCHAR szFilter[] = TEXT ("Bitmap Files (*.BMP)\0*.bmp\0")
TEXT ("All Files (*.*)\0*.*\0\0") ;
BITMAPFILEHEADER bmfh ;
BOOL bSuccess, bTopDown ;
DWORD dwBytesRead ;
HANDLE hFile ;
HDC hdc ;
HMENU hMenu ;
int iInfoSize, iBitsSize, iRowLength, y ;
PAINTSTRUCT ps ;
switch (message)
{
case WM_CREATE:
ofn.lStructSize = sizeof (OPENFILENAME) ;
ofn.hwndOwner = hwnd ;
ofn.hInstance = NULL ;
ofn.lpstrFilter = szFilter ;
ofn.lpstrCustomFilter = NULL ;
ofn.nMaxCustFilter = 0 ;
ofn.nFilterIndex = 0 ;
ofn.lpstrFile = szFileName ;
ofn.nMaxFile = MAX_PATH ;
ofn.lpstrFileTitle = szTitleName ;
ofn.nMaxFileTitle = MAX_PATH ;
ofn.lpstrInitialDir = NULL ;
ofn.lpstrTitle = NULL ;
ofn.Flags = 0 ;
ofn.nFileOffset = 0 ;
ofn.nFileExtension = 0 ;
ofn.lpstrDefExt = TEXT ("bmp") ;
ofn.lCustData = 0 ;
ofn.lpfnHook = NULL ;
ofn.lpTemplateName = NULL ;
return 0 ;
case WM_COMMAND:
hMenu = GetMenu (hwnd) ;
switch (LOWORD (wParam))
{
case IDM_FILE_OPEN:
// Display File Open dialog
if (!GetOpenFileName (&ofn))
return 0 ;
// Get rid of old DIB
if (pbmi)
{
free (pbmi) ;
pbmi = NULL ;
}
if (pBits)
{
free (pBits) ;
pBits = NULL ;
}
// Generate WM_PAINT message to erase background
InvalidateRect (hwnd, NULL, TRUE) ;
UpdateWindow (hwnd) ;
// Open the file
hFile = CreateFile (szFileName, GENERIC_READ,
FILE_SHARE_READ, NULL, OPEN_EXISTING,
FILE_FLAG_SEQUENTIAL_SCAN, NULL) ;
if (hFile == INVALID_HANDLE_VALUE)
{
MessageBox (hwnd, TEXT ("Cannot open file."),
szAppName, MB_ICONWARNING | MB_OK) ;
return 0 ;
}
// Read in the BITMAPFILEHEADER
bSuccess = ReadFile (hFile, &bmfh, sizeof (BITMAPFILEHEADER),
&dwBytesRead, NULL) ;
if (!bSuccess || dwBytesRead != sizeof (BITMAPFILEHEADER))
{
MessageBox (hwnd, TEXT ("Cannot read file."),
szAppName, MB_ICONWARNING | MB_OK) ;
CloseHandle (hFile) ;
return 0 ;
}
// Check that it's a bitmap
if (bmfh.bfType != * (WORD *) "BM")
{
MessageBox (hwnd, TEXT ("File is not a bitmap."),
szAppName, MB_ICONWARNING | MB_OK) ;
CloseHandle (hFile) ;
return 0 ;
}
// Allocate memory for header and bits
iInfoSize = bmfh.bfOffBits - sizeof (BITMAPFILEHEADER) ;
iBitsSize = bmfh.bfSize - bmfh.bfOffBits ;
pbmi = malloc (iInfoSize) ;
pBits = malloc (iBitsSize) ;
if (pbmi == NULL || pBits == NULL)
{
MessageBox (hwnd, TEXT ("Cannot allocate memory."),
szAppName, MB_ICONWARNING | MB_OK) ;
if (pbmi)
free (pbmi) ;
if (pBits)
free (pBits) ;
CloseHandle (hFile) ;
return 0 ;
}
// Read in the Information Header
bSuccess = ReadFile (hFile, pbmi, iInfoSize,
&dwBytesRead, NULL) ;
if (!bSuccess || (int) dwBytesRead != iInfoSize)
{
MessageBox (hwnd, TEXT ("Cannot read file."),
szAppName, MB_ICONWARNING | MB_OK) ;
if (pbmi)
free (pbmi) ;
if (pBits)
free (pBits) ;
CloseHandle (hFile) ;
return 0 ;
}
// Get the DIB width and height
bTopDown = FALSE ;
if (pbmi->bmiHeader.biSize == sizeof (BITMAPCOREHEADER))
{
cxDib = ((BITMAPCOREHEADER *) pbmi)->bcWidth ;
cyDib = ((BITMAPCOREHEADER *) pbmi)->bcHeight ;
cBits = ((BITMAPCOREHEADER *) pbmi)->bcBitCount ;
}
else
{
if (pbmi->bmiHeader.biHeight < 0)
bTopDown = TRUE ;
cxDib = pbmi->bmiHeader.biWidth ;
cyDib = abs (pbmi->bmiHeader.biHeight) ;
cBits = pbmi->bmiHeader.biBitCount ;
if (pbmi->bmiHeader.biCompression != BI_RGB &&
pbmi->bmiHeader.biCompression != BI_BITFIELDS)
{
MessageBox (hwnd, TEXT ("File is compressed."),
szAppName, MB_ICONWARNING | MB_OK) ;
if (pbmi)
free (pbmi) ;
if (pBits)
free (pBits) ;
CloseHandle (hFile) ;
return 0 ;
}
}
// Get the row length
iRowLength = ((cxDib * cBits + 31) & ~31) >> 3 ;
// Read and display
SetCursor (LoadCursor (NULL, IDC_WAIT)) ;
ShowCursor (TRUE) ;
hdc = GetDC (hwnd) ;
for (y = 0 ; y < cyDib ; y++)
{
ReadFile (hFile, pBits + y * iRowLength, iRowLength,
&dwBytesRead, NULL) ;
SetDIBitsToDevice (hdc,
0, // xDst
0, // yDst
cxDib, // cxSrc
cyDib, // cySrc
0, // xSrc
0, // ySrc
bTopDown ? cyDib - y - 1 : y,
// first scan line
1, // number of scan lines
pBits + y * iRowLength,
pbmi,
DIB_RGB_COLORS) ;
}
ReleaseDC (hwnd, hdc) ;
CloseHandle (hFile) ;
ShowCursor (FALSE) ;
SetCursor (LoadCursor (NULL, IDC_ARROW)) ;
return 0 ;
}
break ;
case WM_PAINT:
hdc = BeginPaint (hwnd, &ps) ;
if (pbmi && pBits)
SetDIBitsToDevice (hdc,
0, // xDst
0, // yDst
cxDib, // cxSrc
cyDib, // cySrc
0, // xSrc
0, // ySrc
0, // first scan line
cyDib, // number of scan lines
pBits,
pbmi,
DIB_RGB_COLORS) ;
EndPaint (hwnd, &ps) ;
return 0 ;
case WM_DESTROY:
if (pbmi)
free (pbmi) ;
if (pBits)
free (pBits) ;
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
