第五章 绘图基础（DEVCAPS1）

获取设备环境的信息

 //DEVCAPS1.C--Device Capabilities Display Program No.1 (c) Charles Petzold, 1998
 #include <Windows.h>

 #define NUMLINES ((int) (sizeof(devcaps) / sizeof(devcaps[0])))
 struct
 {
     int iIndex;
     TCHAR *szLabel;
     TCHAR *szDesc;
 }
 devcaps[] =
 {
     HORZSIZE,        TEXT("HORZSIZE"),        TEXT("Width in millimeters:"),
     VERTSIZE,        TEXT("VERTSIZE"),        TEXT("Height in milimeters:"),
     HORZRES,        TEXT("HORZRES"),        TEXT("Width in pixels:"),
     VERTRES,        TEXT("VERTRES"),        TEXT("Height in raster lines:"),
     BITSPIXEL,        TEXT("BITSPIXEL"),        TEXT("Color bits per pixel:"),
     PLANES,            TEXT("PLANES"),            TEXT("Number of color planes:"),
     NUMBRUSHES,        TEXT("NUMBRUSHES"),        TEXT("Number of device brushes"),
     NUMPENS,        TEXT("NUMPENS"),        TEXT("Number of device pens:"),
     NUMMARKERS,        TEXT("NUMMARKERS"),        TEXT("Number of device markers:"),
     NUMFONTS,        TEXT("NUMFONTS"),        TEXT("Number of device fonts:"),
     NUMCOLORS,        TEXT("NUMCOLORS"),        TEXT("Number of device colors:"),
     PDEVICESIZE,    TEXT("PDEVICESIZE"),    TEXT("Size of device structure:"),
     ASPECTX,        TEXT("ASPECTX"),        TEXT("Relative width of pixel:"),
     ASPECTY,        TEXT("ASPECTY"),        TEXT("Relative height of pixel:"),
     ASPECTXY,        TEXT("ASPECTXY"),        TEXT("Relative diagonal of pixel:"),
     LOGPIXELSX,        TEXT("LOGPIXELSX"),        TEXT("Horizontal dots per inch:"),
     LOGPIXELSY,        TEXT("LOGPIXELSY"),        TEXT("Vertical dots per inch:"),
     SIZEPALETTE,    TEXT("SIZEPALETTE"),    TEXT("Number of palette entries:"),
     NUMRESERVED,    TEXT("NUMRESERVED"),    TEXT("Reserved palette entries:"),
     COLORRES,        TEXT("COLORRES"),        TEXT("Actual color resolution:")
 };

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

 int WINAPI WinMain( __in HINSTANCE hInstance
                     , __in_opt HINSTANCE hPrevInstance
                     , __in LPSTR lpCmdLine
                     , __in int nShowCmd )
 {
     static TCHAR szAppName[] = TEXT("DevCaps1");
     HWND hwnd;
     MSG msg;
     WNDCLASS wndclass;

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

     if (!RegisterClass(&wndclass))
     {
         MessageBox(NULL, TEXT("This program requires Window NT!")
             , szAppName, MB_ICONERROR);
         return ;
     }

     hwnd = CreateWindow(szAppName, TEXT("Device Capabilities")
         , WS_OVERLAPPEDWINDOW
         , CW_USEDEFAULT, CW_USEDEFAULT
         , CW_USEDEFAULT, CW_USEDEFAULT
         , NULL, NULL, hInstance, NULL);

     ShowWindow(hwnd, nShowCmd);
     UpdateWindow(hwnd);

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

     return msg.wParam;
 }

 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
     static int cxChar, cxCaps, cyChar;
     TCHAR szBuffer[];
     HDC hdc;
     int i;
     PAINTSTRUCT ps;
     TEXTMETRIC tm;

     switch (message)
     {
     case WM_CREATE:
         hdc = GetDC(hwnd);
         GetTextMetrics(hdc, &tm);
         cxChar = tm.tmAveCharWidth;
         cxCaps = (tm.tmPitchAndFamily &  ?  : ) * cxChar / ;
         cyChar = tm.tmHeight + tm.tmExternalLeading;
         ReleaseDC(hwnd, hdc);
         return ;

     case WM_PAINT:
         hdc = BeginPaint(hwnd, &ps);
         for (i = ; i != NUMLINES; ++i)
         {
             TextOut(hdc, , cyChar * i, devcaps[i].szLabel
                 , lstrlen(devcaps[i].szLabel));
             TextOut(hdc,  * cxCaps, cyChar * i, devcaps[i].szDesc
                 , lstrlen(devcaps[i].szDesc));
             SetTextAlign(hdc, TA_RIGHT | TA_TOP);
             TextOut(hdc,  * cxCaps +  * cxChar, cyChar * i, szBuffer
                 , wsprintf(szBuffer, TEXT("%5d"), GetDeviceCaps(hdc, devcaps[i].iIndex)));
             SetTextAlign(hdc, TA_LEFT | TA_TOP);
         }
         EndPaint(hwnd, &ps);
         return ;

     case WM_DESTROY:
         PostQuitMessage();
         return ;
     }

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

DEVCAPS1.C