最近一直在看Charlse Petzold的《Windows程序设计》，作为一个新得不能再新的新手，只能先照着书的抄抄源码了，之前的例子一直都很正常，但昨天遇到一个很诡异的BUG。
先看实例源码吧：
1 /*----------------------------------------------------------------- 2 ENVIRON.C -- Environment List Box 3 (c) Charles Petzold,1998 4 Copy by XXXX,2015/1/26 5 ------------------------------------------------------------------*/ 6 7 #include <windows.h> 8 9 #define ID_LIST 1 10 #define ID_TEXT 2 11 12 LRESULT CALLBACK WndProc(HWND hwnd, UINT, WPARAM, LPARAM); 13 14 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) 15 { 16 static TCHAR szAppName[] = TEXT("Environ"); 17 HWND hwnd; 18 MSG msg; 19 WNDCLASS wndclass; 20 21 wndclass.style = CS_VREDRAW | CS_HREDRAW; 22 wndclass.lpfnWndProc = WndProc; 23 wndclass.cbClsExtra = 0; 24 wndclass.cbWndExtra = 0; 25 wndclass.hInstance = hInstance; 26 wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION); 27 wndclass.hCursor = LoadCursor(NULL, IDC_ARROW); 28 wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); 29 wndclass.lpszMenuName = NULL; 30 wndclass.lpszClassName = szAppName; 31 32 if (!RegisterClass(&wndclass)) 33 { 34 MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR); 35 return 0; 36 } 37 38 hwnd = CreateWindow(szAppName, TEXT("Environment List Box"), WS_OVERLAPPEDWINDOW, 39 CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL); 40 ShowWindow(hwnd, iCmdShow); 41 UpdateWindow(hwnd); 42 43 while (GetMessage(&msg, NULL, 0, 0)) 44 { 45 TranslateMessage(&msg); 46 DispatchMessage(&msg); 47 } 48 return msg.wParam; 49 } 50 51 52 void FillListBox(HWND hwndList) 53 { 54 int iLength; 55 TCHAR * pVarBlock, *pVarBeg, *pVarEnd, *pVarName; 56 pVarBlock = GetEnvironmentStrings(); //Get pointer to environment block 57 58 while (*pVarBlock) 59 { 60 if (*pVarBlock != '=') //Skip variable names begining with '=' 61 { 62 pVarBeg = pVarBlock; //Beging of variable name 63 while (*(pVarBlock++) != '='); //Scan until '=' 64 pVarEnd = pVarBlock - 1; //Points to '=' sign 65 iLength = pVarEnd - pVarBeg; //Length of variable name 66 67 //Allocate memory for the variable name and terminating 68 //zero.Copy the variable name and append a zero 69 pVarName = calloc(iLength + 1, sizeof(TCHAR)); 70 CopyMemory(pVarName, pVarBeg, iLength * sizeof(TCHAR)); 71 pVarName[iLength] = ' '; 72 73 //Put the variable name int the list box and free memory 74 SendMessage(hwndList, LB_ADDSTRING, 0, (LPARAM)pVarName); 75 free(pVarName); 76 } 77 while (*pVarBlock++ != ' '); //Scna until terminating zero 78 79 } 80 FreeEnvironmentStrings(pVarBlock); 81 int code; 82 code = GetLastError(); 83 } 84 85 86 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) 87 { 88 static HWND hwndList, hwndText; 89 int iIndex, iLength, cxChar, cyChar; 90 TCHAR * pVarName, *pVarValue; 91 92 switch (message) 93 { 94 case WM_CREATE: 95 cxChar = LOWORD(GetDialogBaseUnits()); 96 cyChar = HIWORD(GetDialogBaseUnits()); 97 98 //Create listbox and static text windows 99 hwndList = CreateWindow(TEXT("listbox"), NULL, WS_CHILD | WS_VISIBLE | LBS_STANDARD, 100 cxChar, cyChar * 3, cxChar * 16 + GetSystemMetrics(SM_CXVSCROLL), cyChar * 5, hwnd, 101 (HMENU)ID_LIST, (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), NULL); 102 hwndText = CreateWindow(TEXT("static"), NULL, WS_CHILD | WS_VISIBLE | SS_LEFT, cxChar, cyChar, 103 GetSystemMetrics(SM_CXSCREEN), cyChar, hwnd, (HMENU)ID_TEXT, 104 (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE), NULL); 105 FillListBox(hwndList); 106 return 0; 107 108 109 case WM_SETFOCUS: 110 SetFocus(hwndList); 111 return 0; 112 113 114 case WM_COMMAND: 115 if (LOWORD(wParam) == ID_LIST&&HIWORD(wParam) == LBN_SELCHANGE) 116 { 117 //Get current selectiong 118 iIndex = SendMessage(hwndList, LB_GETCURSEL, 0, 0); 119 iLength = SendMessage(hwndList, LB_GETTEXTLEN, iIndex, 0) + 1; 120 pVarName = calloc(iLength, sizeof(TCHAR)); 121 SendMessage(hwndList, LB_GETTEXT, iIndex, (LPARAM)pVarName); 122 123 //Get environment string 124 iLength = GetEnvironmentVariable(pVarName, NULL, 0); 125 pVarValue = calloc(iLength, sizeof(TCHAR)); 126 GetEnvironmentVariable(pVarName, pVarValue, iLength); 127 128 //Show it in window 129 SetWindowText(hwndText, pVarValue); 130 free(pVarName); 131 free(pVarValue); 132 } 133 return 0; 134 135 136 case WM_DESTROY: 137 PostQuitMessage(0); 138 return 0; 139 } 140 return DefWindowProc(hwnd, message, wParam, lParam); 141 }
编译什么的都没有错误提示，但是在本地调试时提示触发一个断点，但是我确定我没有下过断点！！！
提示如图：
选择“继续”后会又提示一个中断，提示堆被损坏
作为一个小彩笔，真心弄不懂，求教大牛！！！