/*-----------------------------------------------
SYSMETS.H -- System metrics display structure
-----------------------------------------------*/#define NUMLINES ((int) (sizeof sysmetrics / sizeof sysmetrics [0]))struct
{
int iIndex ;
TCHAR * szLabel ;
TCHAR * szDesc ;
}
sysmetrics [] =
{
SM_CXSCREEN, TEXT ("SM_CXSCREEN"),
TEXT ("Screen width in pixels"),
SM_CYSCREEN, TEXT ("SM_CYSCREEN"),
TEXT ("Screen height in pixels"),
SM_CXVSCROLL, TEXT ("SM_CXVSCROLL"),
TEXT ("Vertical scroll width"),
SM_CYHSCROLL, TEXT ("SM_CYHSCROLL"),
TEXT ("Horizontal scroll height"),
SM_CYCAPTION, TEXT ("SM_CYCAPTION"),
TEXT ("Caption bar height"),
SM_CXBORDER, TEXT ("SM_CXBORDER"),
TEXT ("Window border width"),
SM_CYBORDER, TEXT ("SM_CYBORDER"),
TEXT ("Window border height"),
SM_CXFIXEDFRAME, TEXT ("SM_CXFIXEDFRAME"),
TEXT ("Dialog window frame width"),
SM_CYFIXEDFRAME, TEXT ("SM_CYFIXEDFRAME"),
TEXT ("Dialog window frame height"),
SM_CYVTHUMB, TEXT ("SM_CYVTHUMB"),
TEXT ("Vertical scroll thumb height"),
SM_CXHTHUMB, TEXT ("SM_CXHTHUMB"),
TEXT ("Horizontal scroll thumb width"),
SM_CXICON, TEXT ("SM_CXICON"),
TEXT ("Icon width"),
SM_CYICON, TEXT ("SM_CYICON"),
TEXT ("Icon height"),
SM_CXCURSOR, TEXT ("SM_CXCURSOR"),
TEXT ("Cursor width"),
SM_CYCURSOR, TEXT ("SM_CYCURSOR"),
TEXT ("Cursor height"),
SM_CYMENU, TEXT ("SM_CYMENU"),
TEXT ("Menu bar height"),
SM_CXFULLSCREEN, TEXT ("SM_CXFULLSCREEN"),
TEXT ("Full screen client area width"),
SM_CYFULLSCREEN, TEXT ("SM_CYFULLSCREEN"),
TEXT ("Full screen client area height"),
SM_CYKANJIWINDOW, TEXT ("SM_CYKANJIWINDOW"),
TEXT ("Kanji window height"),
SM_MOUSEPRESENT, TEXT ("SM_MOUSEPRESENT"),
TEXT ("Mouse present flag"),
SM_CYVSCROLL, TEXT ("SM_CYVSCROLL"),
TEXT ("Vertical scroll arrow height"),
SM_CXHSCROLL, TEXT ("SM_CXHSCROLL"),
TEXT ("Horizontal scroll arrow width"),
SM_DEBUG, TEXT ("SM_DEBUG"),
TEXT ("Debug version flag"),
SM_SWAPBUTTON, TEXT ("SM_SWAPBUTTON"),
TEXT ("Mouse buttons swapped flag"),
SM_CXMIN, TEXT ("SM_CXMIN"),
TEXT ("Minimum window width"),
SM_CYMIN, TEXT ("SM_CYMIN"),
TEXT ("Minimum window height"),
SM_CXSIZE, TEXT ("SM_CXSIZE"),
TEXT ("Min/Max/Close button width"),
SM_CYSIZE, TEXT ("SM_CYSIZE"),
TEXT ("Min/Max/Close button height"),
SM_CXSIZEFRAME, TEXT ("SM_CXSIZEFRAME"),
TEXT ("Window sizing frame width"),
SM_CYSIZEFRAME, TEXT ("SM_CYSIZEFRAME"),
TEXT ("Window sizing frame height"),
SM_CXMINTRACK, TEXT ("SM_CXMINTRACK"),
TEXT ("Minimum window tracking width"),
} ;
/*----------------------------------------------------
SYSMETS1.C -- System Metrics Display Program No. 1
(c) Charles Petzold, 1998
----------------------------------------------------*/#define WINVER 0x0500
#include <windows.h>
#include "sysmets.h"LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("SysMets1") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ; 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 ; if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("This program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
} hwnd = CreateWindow (szAppName, TEXT ("Get System Metrics No. 1"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ;
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 int cxChar, cxCaps, cyChar ;
HDC hdc ;
int i ;
PAINTSTRUCT ps ;
TCHAR szBuffer [10] ;
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) ;
return 0 ; case WM_PAINT :
hdc = BeginPaint (hwnd, &ps) ; for (i = 0 ; i < NUMLINES ; i++)
{
TextOut (hdc, 0, cyChar * i,
sysmetrics[i].szLabel,//头文件中定义的sysmetrics是一个数组,怎么又用到了结构体中的szLabel,下面一个也是这样???
lstrlen (sysmetrics[i].szLabel)) ; TextOut (hdc, 22 * cxCaps, cyChar * i,
sysmetrics[i].szDesc,
lstrlen (sysmetrics[i].szDesc)) ; SetTextAlign (hdc, TA_RIGHT | TA_TOP) ; TextOut (hdc, 22 * cxCaps + 40 * cxChar, cyChar * i, szBuffer,//这里为什么要使用szBuffer?? szBuffer不是一个数组吗??
wsprintf (szBuffer, TEXT ("%5d"),
GetSystemMetrics (sysmetrics[i].iIndex))) ; SetTextAlign (hdc, TA_LEFT | TA_TOP) ;
}
EndPaint (hwnd, &ps) ;
return 0 ; case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
SYSMETS.H -- System metrics display structure
-----------------------------------------------*/#define NUMLINES ((int) (sizeof sysmetrics / sizeof sysmetrics [0]))struct
{
int iIndex ;
TCHAR * szLabel ;
TCHAR * szDesc ;
}
sysmetrics [] =
{
SM_CXSCREEN, TEXT ("SM_CXSCREEN"),
TEXT ("Screen width in pixels"),
SM_CYSCREEN, TEXT ("SM_CYSCREEN"),
TEXT ("Screen height in pixels"),
SM_CXVSCROLL, TEXT ("SM_CXVSCROLL"),
TEXT ("Vertical scroll width"),
SM_CYHSCROLL, TEXT ("SM_CYHSCROLL"),
TEXT ("Horizontal scroll height"),
SM_CYCAPTION, TEXT ("SM_CYCAPTION"),
TEXT ("Caption bar height"),
SM_CXBORDER, TEXT ("SM_CXBORDER"),
TEXT ("Window border width"),
SM_CYBORDER, TEXT ("SM_CYBORDER"),
TEXT ("Window border height"),
SM_CXFIXEDFRAME, TEXT ("SM_CXFIXEDFRAME"),
TEXT ("Dialog window frame width"),
SM_CYFIXEDFRAME, TEXT ("SM_CYFIXEDFRAME"),
TEXT ("Dialog window frame height"),
SM_CYVTHUMB, TEXT ("SM_CYVTHUMB"),
TEXT ("Vertical scroll thumb height"),
SM_CXHTHUMB, TEXT ("SM_CXHTHUMB"),
TEXT ("Horizontal scroll thumb width"),
SM_CXICON, TEXT ("SM_CXICON"),
TEXT ("Icon width"),
SM_CYICON, TEXT ("SM_CYICON"),
TEXT ("Icon height"),
SM_CXCURSOR, TEXT ("SM_CXCURSOR"),
TEXT ("Cursor width"),
SM_CYCURSOR, TEXT ("SM_CYCURSOR"),
TEXT ("Cursor height"),
SM_CYMENU, TEXT ("SM_CYMENU"),
TEXT ("Menu bar height"),
SM_CXFULLSCREEN, TEXT ("SM_CXFULLSCREEN"),
TEXT ("Full screen client area width"),
SM_CYFULLSCREEN, TEXT ("SM_CYFULLSCREEN"),
TEXT ("Full screen client area height"),
SM_CYKANJIWINDOW, TEXT ("SM_CYKANJIWINDOW"),
TEXT ("Kanji window height"),
SM_MOUSEPRESENT, TEXT ("SM_MOUSEPRESENT"),
TEXT ("Mouse present flag"),
SM_CYVSCROLL, TEXT ("SM_CYVSCROLL"),
TEXT ("Vertical scroll arrow height"),
SM_CXHSCROLL, TEXT ("SM_CXHSCROLL"),
TEXT ("Horizontal scroll arrow width"),
SM_DEBUG, TEXT ("SM_DEBUG"),
TEXT ("Debug version flag"),
SM_SWAPBUTTON, TEXT ("SM_SWAPBUTTON"),
TEXT ("Mouse buttons swapped flag"),
SM_CXMIN, TEXT ("SM_CXMIN"),
TEXT ("Minimum window width"),
SM_CYMIN, TEXT ("SM_CYMIN"),
TEXT ("Minimum window height"),
SM_CXSIZE, TEXT ("SM_CXSIZE"),
TEXT ("Min/Max/Close button width"),
SM_CYSIZE, TEXT ("SM_CYSIZE"),
TEXT ("Min/Max/Close button height"),
SM_CXSIZEFRAME, TEXT ("SM_CXSIZEFRAME"),
TEXT ("Window sizing frame width"),
SM_CYSIZEFRAME, TEXT ("SM_CYSIZEFRAME"),
TEXT ("Window sizing frame height"),
SM_CXMINTRACK, TEXT ("SM_CXMINTRACK"),
TEXT ("Minimum window tracking width"),
} ;
/*----------------------------------------------------
SYSMETS1.C -- System Metrics Display Program No. 1
(c) Charles Petzold, 1998
----------------------------------------------------*/#define WINVER 0x0500
#include <windows.h>
#include "sysmets.h"LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("SysMets1") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ; 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 ; if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("This program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
} hwnd = CreateWindow (szAppName, TEXT ("Get System Metrics No. 1"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ;
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 int cxChar, cxCaps, cyChar ;
HDC hdc ;
int i ;
PAINTSTRUCT ps ;
TCHAR szBuffer [10] ;
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) ;
return 0 ; case WM_PAINT :
hdc = BeginPaint (hwnd, &ps) ; for (i = 0 ; i < NUMLINES ; i++)
{
TextOut (hdc, 0, cyChar * i,
sysmetrics[i].szLabel,//头文件中定义的sysmetrics是一个数组,怎么又用到了结构体中的szLabel,下面一个也是这样???
lstrlen (sysmetrics[i].szLabel)) ; TextOut (hdc, 22 * cxCaps, cyChar * i,
sysmetrics[i].szDesc,
lstrlen (sysmetrics[i].szDesc)) ; SetTextAlign (hdc, TA_RIGHT | TA_TOP) ; TextOut (hdc, 22 * cxCaps + 40 * cxChar, cyChar * i, szBuffer,//这里为什么要使用szBuffer?? szBuffer不是一个数组吗??
wsprintf (szBuffer, TEXT ("%5d"),
GetSystemMetrics (sysmetrics[i].iIndex))) ; SetTextAlign (hdc, TA_LEFT | TA_TOP) ;
}
EndPaint (hwnd, &ps) ;
return 0 ; case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
结构数组中的一个成员
2。TextOut (hdc, 22 * cxCaps + 40 * cxChar, cyChar * i, szBuffer,//这里为什么要使用szBuffer?? szBuffer不是一个数组吗??The TextOut function writes a character string at the specified location, using the currently selected font, background color, and text color. BOOL TextOut(
HDC hdc, // handle to device context
int nXStart, // x-coordinate of starting position
int nYStart, // y-coordinate of starting position
LPCTSTR lpString, // pointer to string
int cbString // number of characters in string
);
其中LPCTSTR lpString为const char *
每一个systmetrics[i]的结构是
struct
{
int iIndex ;
TCHAR * szLabel ;
TCHAR * szDesc ;
};
注意源代码中struct{}结束后没有";"符号 他接着做数组的定义了
szbuffer[]是一个数组 当做参数写为szbuffer时候会自动做一个隐式转换
等于传入了szbuffer[]数组的首地址
其实你写成&szbuffer[0]也可以 这样更好理解 传参数时和szbuffer是一样的
2、数组名就是指针
wsprintf (szBuffer, TEXT ("%5d"), GetSystemMetrics (sysmetrics[i].iIndex)
将%5d做一个格式化定义 然后将GetSystemMetrics(sysmetrics[i].iIndex)的值按照这个格式复制到szBuffer中 同时wsprintf返回一个szBuffer的长度 正好符合TextOut()函数最后一个参数的要求