一、實現(xiàn)方法
在Visual C++編程中,最安全的殺死進(jìn)程的方法是向運行程序的主窗口發(fā)送WM_CLOSE消息,其實現(xiàn)代碼如下:
HWND hwnd =this.m_hWnd; // 獲得主窗口 PostMessage(hwnd, WM_CLOSE, 0, 0); |
發(fā)送此消息后,通常應(yīng)該等待直到進(jìn)程確實終止,當(dāng)進(jìn)程終止時,它發(fā)出狀態(tài)信號,并且 WaitForSingleObject 返回WAIT_OBJECT_0。如果返回別的值,進(jìn)程要么掛起了,要么仍然在進(jìn)行處理。在這種情況下,殺死這個進(jìn)程的唯一方法是用功能更強大的API函數(shù):TerminateProcess()。如果想干得漂亮一點,可以在關(guān)閉之前向主窗口發(fā)送一個WM_QUERYENDSESSION消息,當(dāng)用戶結(jié)束會話(log out)或者調(diào)用ExitWindows()函數(shù)時,應(yīng)用程序會收到這個消息,然后準(zhǔn)備退出進(jìn)程,此時一般都會彈出一個確認(rèn)對話框,告訴用戶:"程序要推出了,如果要保存修改的東西,現(xiàn)在是最佳時機(jī),想保存嗎?"有三種選擇(Yes/No/Cancel)。此外,發(fā)送WM_QUERYENDSESSION消息可以拒絕推出進(jìn)程(按下"Cancel鍵"),如果是這樣,進(jìn)程將會延續(xù)。
如果想要關(guān)閉的進(jìn)程被掛起,使用SendMessageTimeout()函數(shù)就非常重要,而不是用SendMessage()函數(shù),其參數(shù)SMTO_NOTIMEOUTIFNOTHUNG是一個只有Windows 2000 和Windows XP才有的標(biāo)志。其意義是"如果線程沒有掛起,不要超時",換句話說就是如果線程正在進(jìn)行正常處理,那么永遠(yuǎn)等待,以便用戶能看到對話框并決定做什么,當(dāng)用戶最終做出決定后,SendMessageTimeout()將帶著相應(yīng)的bOKToKill值返回。
本例為了增強代碼的可重用性,將實現(xiàn)細(xì)節(jié)都封裝在一個叫CFindKillProcess的類中,包括查找和殺死進(jìn)程,詳情請參見EnumProc.h和EnumProc.cpp文件。文件中還有另外兩個可重用類,一個是CProcessIterator,另一個是CWindowIterator。
CfindKillProcess類的成員函數(shù)FindProcess()查找某個進(jìn)程序,如果找到這個進(jìn)程,它返回此進(jìn)程的ID,然后將此ID傳給CFindKillProcess::KillProcess()函數(shù),KillProcess()函數(shù)封裝了關(guān)閉窗口以及終止邏輯,它利用CmainWindowIterator類對象來枚舉進(jìn)程的主窗口(可能不止一個,見"如何獲取某個進(jìn)程的主窗口以及創(chuàng)建進(jìn)程的程序名?"),并發(fā)送WM_CLOSE到每一個窗口,然后等待進(jìn)程死亡。它有一個布爾型參數(shù)用來指示當(dāng)應(yīng)用程序進(jìn)程不愿意退出時是否執(zhí)行TerminateProcess()函數(shù)。詳細(xì)細(xì)節(jié)請參見下載的代碼。
二、編程步驟
1、 啟動Visual C++6.0,生成一個控制臺應(yīng)用程序,將該程序命名為"kp";
2、 在程序代碼中添加CfindKillProcess、CProcessIterator類的定義;
3、 添加代碼,編譯運行程序。
三、程序代碼
/////////////////////////////////////////////////////////////////////////////////////////// #pragma once ////////////////// // Process iterator -- iterator over all system processes // Always skips the first (IDLE) process with PID=0. class CProcessIterator { protected: DWORD* m_pids; // array of procssor IDs DWORD m_count; // size of array DWORD m_current; // next array item public: CProcessIterator(); ~CProcessIterator(); DWORD First(); DWORD Next() { return m_pids && m_current < m_count ? m_pids[m_current++] : 0; } DWORD GetCount() { return m_count; } }; ////////////////// // Handy class to facilitate finding and killing a process by name. class CFindKillProcess { public: CFindKillProcess(); ~CFindKillProcess(); DWORD FindProcess(LPCTSTR lpModname, BOOL bAddExe=TRUE); BOOL KillProcess(DWORD pid, BOOL bZap); }; /////////////////////////////////////////////////////////////////////////////////////////////// #include "stdafx.h" #include "EnumProc.h" // CProcessIterator - Iterates all processes CProcessIterator::CProcessIterator() { m_pids = NULL; } CProcessIterator::~CProcessIterator() { delete [] m_pids; } ////////////////// // Get first process: Call EnumProcesses to init array. Return first one. DWORD CProcessIterator::First() { m_current = (DWORD)-1; m_count = 0; DWORD nalloc = 1024; do { delete [] m_pids; m_pids = new DWORD [nalloc]; if (EnumProcesses(m_pids, nalloc*sizeof(DWORD), &m_count)) { m_count /= sizeof(DWORD); m_current = 1; // skip IDLE process } } while (nalloc <= m_count); return Next(); } //////////////////////////////////////////////////////////////// // CFindKillProcess - to find/kill a process by module name. // CFindKillProcess::CFindKillProcess() {} CFindKillProcess::~CFindKillProcess() {} ////////////////// // Search for process whose module name matches parameter. // Finds "foo" or "foo.exe" DWORD CFindKillProcess::FindProcess(LPCTSTR modname, BOOL bAddExe) { CProcessIterator itp; for (DWORD pid=itp.First(); pid; pid=itp.Next()) { TCHAR name[_MAX_PATH]; CProcessModuleIterator itm(pid); HMODULE hModule = itm.First(); // .EXE if (hModule) { GetModuleBaseName(itm.GetProcessHandle(),hModule, name, _MAX_PATH); string sModName = modname; if (strcmpi(sModName.c_str(),name)==0) return pid; sModName += ".exe"; if (bAddExe && strcmpi(sModName.c_str(),name)==0) return pid; } } return 0; } ////////////////// // Kill a process cleanly: Close main windows and wait. // bZap=TRUE to force kill. BOOL CFindKillProcess::KillProcess(DWORD pid, BOOL bZap) { CMainWindowIterator itw(pid); for (HWND hwnd=itw.First(); hwnd; hwnd=itw.Next()) { DWORD bOKToKill = FALSE; SendMessageTimeout(hwnd, WM_QUERYENDSESSION, 0, 0,SMTO_ABORTIFHUNG|SMTO_NOTIMEOUTIFNOTHUNG,100, &bOKToKill); if (!bOKToKill) return FALSE; // window doesn't want to die: abort PostMessage(hwnd, WM_CLOSE, 0, 0); } // I've closed the main windows; now wait for process to die. BOOL bKilled = TRUE; HANDLE hp=OpenProcess(SYNCHRONIZE|PROCESS_TERMINATE,FALSE,pid); if (hp) { if (WaitForSingleObject(hp, 5000) != WAIT_OBJECT_0) { if (bZap) { // didn't die: force kill it if zap requested TerminateProcess(hp,0); } else { bKilled = FALSE; } } CloseHandle(hp); } return bKilled; } ////////////////////////////////////////////////////////////////////////// #include "stdafx.h" #include "EnumProc.h" #define tpf _tprintf // to save typing typedef list<string> CStringList; // like MFC, but with STL // pre-declare functions int help(); // check for switch: / or - inline BOOL isswitch(TCHAR c) { return c==L'/' || c==L'-'; } int main(int argc, TCHAR* argv[], TCHAR* envp[]) { CStringList cmdargs; // command-line args (processes to kill) BOOL bDisplayOnly=FALSE; // don't kill, just show results BOOL bQuiet=FALSE; // suppress error messages BOOL bZap=FALSE; // force-kill process // Parse command line. Switches can come in any order. for (int i=1; i<argc; i++) { if (isswitch(argv[i][0])) { for (UINT j=1; j<strlen(argv[i]); j++) { switch(tolower(argv[i][j])) { case '?': help(); return 0; case 'n': bDisplayOnly=TRUE; break; case 'q': bQuiet=TRUE; break; case 'z': bZap=TRUE; break; default: return help(); } } } else { cmdargs.push_back(argv[i]); // got a non-switch arg: add to list } } if (cmdargs.size()<=0) help(); // Now iterate args (module names), killing each one CStringList::iterator it; for (it=cmdargs.begin(); it!=cmdargs.end(); it++) { CFindKillProcess fkp; DWORD pid = fkp.FindProcess(it->c_str()); if (pid) { if (bDisplayOnly) { tpf(_T("Kill process %d(0x%08x)\n"),pid,pid); } else { fkp.KillProcess(pid, bZap); } } else if (!bQuiet) { tpf(_T("Error: Can't find process '%s'.\n"),it->c_str()); } } return 0; } int help() { tpf(_T("kp: Kill process from command line.\n")); tpf(_T(" Copyright 2002 Paul DiLascia.\n\n")); tpf(_T(" kp [/nqz?] modname1 [modname2....]\n")); tpf(_T(" where modnameN is a module name; eg foo or foo.exe\n")); tpf(_T("\n")); tpf(_T(" /n(othing) don't kill, just show results\n")); tpf(_T(" /q(uiet) don't show errors\n")); tpf(_T(" /z(ap) force kill (ignore WM_QUERYENDSESSION)\n")); tpf(_T("\n")); return 0; } |
四、小結(jié)
本實例通過介紹CfindKillProcess類探討了在Windows2000下徹底消除進(jìn)程的方法,雖然該程序只能在Windows2000環(huán)境下編譯運行,但是該方法對Windows98下進(jìn)程的控制也是有借鑒意義的.