是第九章的倒数第二个程序，ENVIRON，代码如下：

#include<windows.h>#
define ID_LIST 1#define ID_TEXT 2
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance, PSTR szCmdLine,int iCmdShow){static TCHAR szAppName[]=TEXT("Environ");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)(COLOR_WINDOW+1);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("Environmrnt List Box"), 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;}
void FillListBox(HWND hwndList){int iLength;TCHAR*pVarBlock,*pVarBeg,*pVarEnd,*pVarName;
pVarBlock=GetEnvironmentStrings();
while(*pVarBlock){if(*pVarBlock!='='){pVarBeg=pVarBlock;while(*pVarBlock++!='=');pVarEnd=pVarBlock-1;iLength=pVarEnd-pVarBeg;
pVarName =(TCHAR*) calloc(iLength+1,sizeof(TCHAR));CopyMemory(pVarName,pVarBeg,iLength*sizeof(TCHAR));pVarName[iLength]='\0';
SendMessage(hwndList,LB_ADDSTRING,0,(LPARAM)pVarName);free(pVarName);}while(*pVarBlock++!='\0');}FreeEnvironmentStrings(pVarBlock);}
LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam){static HWND hwndList,hwndText;int iIndex,iLength,cxChar,cyChar;TCHAR *pVarName,*pVarValue;
switch(message){case WM_CREATE:cxChar=LOWORD(GetDialogBaseUnits());cyChar=HIWORD(GetDialogBaseUnits());
hwndList=CreateWindow(TEXT("listbox"),NULL,WS_CHILD|WS_VISIBLE|LBS_STANDARD,cxChar,cyChar*3,cxChar*16+GetSystemMetrics(SM_CXVSCROLL),cyChar*5,hwnd,(HMENU)ID_LIST,(HINSTANCE)GetWindowLong(hwnd,GWL_HINSTANCE),NULL);
hwndText=CreateWindow(TEXT("static"),NULL,WS_CHILD|WS_VISIBLE|SS_LEFT,cxChar,cyChar,GetSystemMetrics(SM_CXSCREEN),cyChar,hwnd,(HMENU)ID_TEXT,(HINSTANCE)GetWindowLong(hwnd,GWL_HINSTANCE),NULL);
FillListBox(hwndList);return 0;
case WM_SETFOCUS:SetFocus(hwndList);return 0;
case WM_COMMAND:if(LOWORD(wParam)==ID_LIST&&HIWORD(wParam)==LBN_SELCHANGE){iIndex=SendMessage(hwndList,LB_GETCURSEL,0,0);iLength=SendMessage(hwndList,LB_GETTEXTLEN,iIndex,0)+1;pVarName=(TCHAR*)calloc(iLength,sizeof(TCHAR));SendMessage(hwndList,LB_GETTEXT,iIndex,(LPARAM)pVarName);
iLength=GetEnvironmentVariable(pVarName,NULL,0);pVarValue=(TCHAR*)calloc(iLength,sizeof(TCHAR));GetEnvironmentVariable(pVarName,pVarValue,iLength);
SetWindowText(hwndText,pVarValue);free(pVarName);free(pVarValue);}return 0;
case WM_DESTROY:PostQuitMessage(0);return 0;}return DefWindowProc(hwnd,message,wParam,lParam);}
（我去，我也不知道为啥就这样了）
其中做了点修改，要不然就报错，可是还是没有结果。麻烦哪位大神运行一下，这是为什么啊？谢谢阿！

还没看到那章呢。。。