这是源代码：
#include
#include"resource.h"
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
static char szAppName[] = "SysMets2";
HWND hwnd;
MSG msg;
WNDCLASS wndclass;
if (!hPrevInstance)
{
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 = NULL;
wndclass.lpszClassName = szAppName;
RegisterClass(&wndclass);
}
hwnd = CreateWindow(szAppName, "Get System Metrics No.2",
WS_OVERLAPPEDWINDOW|WS_HSCROLL|WS_VSCROLL,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL
);
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static short cxChar, cxCaps, cyChar, cxClient, cyClient, nHscrollPos,nMaxWidth,nVscrollPos,nVscrollMax,nHscrollMax;
char szBuffer[10];
HDC hdc;
short i,x,y,nPaintBeg,nPaintEnd,nVscrollInc,nHscrollInc;
PAINTSTRUCT ps;
TEXTMETRIC tm;
switch (message)
{
case WM_CREATE:
hdc = GetDC(hwnd);
GetTextMetrics(hdc, &tm);
cxChar = tm.tmAveCharWidth;
cxCaps = (tm.tmPitchAndFamily & 1 ? 3 : 2)*cxChar / 2;
cyChar = tm.tmHeight + tm.tmExternalLeading;
ReleaseDC(hwnd, hdc);
nMaxWidth = 40 * cxChar + 18 * cxCaps;
return 0;
case WM_SIZE:
cyClient = HIWORD(lParam);
cxClient = LOWORD(lParam);
nVscrollMax = max(0, NUMLINES + 2 - cyClient / cyChar);
nVscrollPos = min(nVscrollPos, nVscrollMax);
SetScrollRange(hwnd, SB_VERT, 0, nVscrollMax, FALSE);
SetScrollPos(hwnd, SB_VERT, nVscrollPos, TRUE);
nHscrollMax = max(0, 2 + (nMaxWidth - cxClient) / cxChar);
nHscrollPos = min(nHscrollPos, nHscrollMax);
SetScrollRange(hwnd, SB_HORZ, 0, nHscrollMax, FALSE);
SetScrollPos(hwnd, SB_HORZ, nHscrollPos, TRUE);
return 0;
case WM_VSCROLL:
switch (wParam)
{
case SB_TOP:
nVscrollInc = -nVscrollPos;
break;
case SB_BOTTOM:
nVscrollInc = nVscrollMax - nVscrollPos;
break;
case SB_LINEUP:
nVscrollInc = -1;
break;
case SB_LINEDOWN:
nVscrollInc = 1;
case SB_PAGEUP:
nVscrollPos = min(-1, -cyClient / cyChar);
break;
case SB_PAGEDOWN:
nVscrollPos = max(1, cyClient / cyChar);
break;
case SB_THUMBTRACK:
nVscrollInc = LOWORD(lParam) - nVscrollPos;
break;
default:
nVscrollInc = 0;
}
if (nVscrollInc == max(-nVscrollPos, min(nVscrollInc, nVscrollMax - nVscrollPos)))
{
nVscrollPos += nVscrollInc;
ScrollWindow(hwnd, 0, -cyChar*nVscrollInc, NULL, NULL);
SetScrollPos(hwnd, SB_VERT, nVscrollPos, TRUE);
UpdateWindow(hwnd);
}
return 0;
case WM_HSCROLL:
switch (wParam)
{
case SB_LINEDOWN:
nHscrollPos = 1;
break;
case SB_LINEUP:
nHscrollPos =- 1;
break;
case SB_PAGEUP:
nHscrollPos = -8;
break;
case SB_PAGEDOWN:
nHscrollPos = 8;
break;
case SB_THUMBPOSITION:
nHscrollInc = LOWORD(lParam) - nHscrollPos;
break;
default:
nHscrollInc=0;
}
if (nHscrollPos = max(-nHscrollPos, min(nHscrollInc, nHscrollMax - nHscrollPos)))
{
nHscrollPos += nHscrollInc;
ScrollWindow(hwnd, -cxChar*nHscrollInc, 0, NULL, NULL);
SetScrollPos(hwnd, SB_HORZ, nHscrollPos, TRUE);
}
return 0;
case WM_PAINT:
hdc = BeginPaint(hwnd, &ps);
nPaintBeg = max(0,nVscrollPos+ps.rcPaint.top/cyChar-1);
nPaintEnd = min(NUMLINES,nVscrollPos=ps.rcPaint.bottom/cyChar);
for (i = nPaintBeg; i < nPaintEnd; i++)
{
x = cxChar*(1-nHscrollPos);
y = cyChar*(1-nVscrollPos+i);
TextOut(hdc,cxChar,y,
sysmetrics[i].szLabel,
lstrlen(sysmetrics[i].szLabel)
);
TextOut(hdc, x+18*cxCaps,y,
sysmetrics[i].szDesc,
lstrlen(sysmetrics[i].szDesc)
);
SetTextAlign(hdc,TA_RIGHT | TA_TOP);
TextOut(hdc,x+18*cxCaps+40*cxChar,
y, szBuffer,
wsprintf(szBuffer, "%5d",
GetSystemMetrics(sysmetrics[i].nIndex))
);
SetTextAlign(hdc, TA_LEFT| TA_TOP);
}
EndPaint(hwnd, &ps);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd, message, wParam, lParam);
}
这是resource.h中的代码：
//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ generated include file.
// Used by Win32Project1.rc
// 新对象的下一组默认值
//
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE 101
#define _APS_NEXT_COMMAND_VALUE 40001
#define _APS_NEXT_CONTROL_VALUE 1001
#define _APS_NEXT_SYMED_VALUE 101
#endif
#endif
#define NUMLINES (sizeof sysmetrics/sizeof sysmetrics[0])
struct
{
int nIndex;
char *szLabel;
char *szDesc;
}
sysmetrics[] =
{
SM_CXSCREEN, "SM_CXSCREEN", "Screen with in pixels",
SM_CYSCREEN, "SM_CYSCREEN", "Screen height in pixels",
SM_CXVSCROLL, "SM_CXVSCROLL", "Vertical scroll arrow width",
SM_CYHSCROLL, "SM_CYHSCROLL", "Horizontal scroll arrow height",
SM_CYCAPTION, "SM_CYCAPTION", "Caption bar height",
SM_CXBORDER, "SM_CXBORDER", "border width",
SM_CYBORDER, "SM_CYBORDER", "border height",
SM_CXDLGFRAME, "SM_CXDLGFRAME", "Dialog window frame width",
SM_CYDLGFRAME, "SM_CYDLGFRAME", "Dialog window frame height",
SM_CYVTHUMB, "SM_CYVTHUMB", "Vertical scroll thumb height",
SM_CXHTHUMB, "SM_CXHTHUMB", "Horizontal scroll thumb height",
SM_CXICON, "SM_CXICON", "Icon width",
SM_CYICON, "SM_CYICON", "icon height",
SM_CXCURSOR, "SM_CXCURSOR", "Cursor width",
SM_CYCURSOR, "SM_CYCURSOR", "Cursor height",
SM_CYMENU, "SM_CYMENU", "Menu bar height",
SM_CXFULLSCREEN, "SM_CXFULLSCREEN", "Full-screen client window width",
SM_CYFULLSCREEN, "SM_CYFULLSCREEN", "Full-screen client window height",
SM_CYKANJIWINDOW, "SM_CYKANJIWINDOW", "Kanji window height",
SM_MOUSEPRESENT, "SM_MOUSEPRESENT", "Mouse present flag",
SM_CYVSCROLL, "SM_CYVSCROLL", "vertical scroll arrow height",
SM_CXHSCROLL, "SM_CXHSCROLL", "Horiozntal scroll arrow width",
SM_DEBUG, "SM_DEBUG", "Debug version flag",
SM_SWAPBUTTON, "SM_SWAPBUTTON", "Mouse buttons swapped flag",
SM_RESERVED1, "SM_RESERVED1", "Reserved",
SM_RESERVED2, "SM_RESERVED2", "Reserved",
SM_RESERVED3, "SM_RESERVED3", "Reserved",
SM_RESERVED4, "SM_RESERVED4", "Reserved",
SM_CXMIN, "SM_CXMIN", "Mininum window width",
SM_CYMIN, "SM_CYMIN", "Mininum window height",
SM_CXSIZE, "SM_CXSIZE", "Minimize/Maximize icon width",
SM_CYSIZE, "SM_CYSIZE", "Minimize/Maximize icon height",
SM_CXFRAME, "SM_CXFRAME", "Window frame width",
SM_CYFRAME, "SM_CYFRAME", "Window frame height",
SM_CXMINTRACK, "SM_CXMINTRACK", "Minimize tracking width of window",
SM_CYMINTRACK, "SM_CYMINTRACK", "Minimize tracking height of window",
SM_CMETRICS, "SM_CMETRICS", "Number of system metrics"
};
下面是运行结果：
