註冊應用程式復原
本節提供在應用程式中實作復原功能的詳細資料。 您應該考慮實作這項功能來處理下列情況：
-
當應用程式意外停止運作時，防止資料遺失。
-
可讓使用者在應用程式因為軟體更新安裝而關閉時順暢地取回應用程式資料 (，而不讓使用者有機會儲存資料) 。
當應用程式遇到未處理的例外狀況或停止回應時復原
若要註冊復原回呼，請呼叫 RegisterApplicationRecoveryCallback 函式。 Windows 錯誤報告 (WER) 在應用程式因未處理的例外狀況或應用程式未回應而結束之前呼叫復原回呼。
您可以使用復原回呼，嘗試在應用程式終止之前儲存資料和狀態資訊。 然後，您可以在重新開機應用程式時，使用已儲存的資料和狀態資訊。
在復原過程中，您必須在指定的 Ping 間隔內呼叫 ApplicationRecoveryInProgress 函式;否則，復原程式會終止。 呼叫 ApplicationRecoveryInProgress 可讓 WER 知道您仍在主動復原資料。 當復原程式完成時，請呼叫 ApplicationRecoveryFinished 函式 。 請注意， ApplicationRecoveryFinished 函式應該是您在結束之前進行的最後一個呼叫，因為函式會立即終止應用程式。
您應該考慮在應用程式程式的正常過程中定期儲存資料和狀態資訊的暫存複本。 定期儲存資料可能會節省復原程式中的時間。
由於軟體更新而關閉應用程式時，儲存資料和應用程式狀態
如果 Windows 應用程式可以更新，應用程式也應該處理 WM_QUERYENDSESSION 和 WM_ENDSESSION 訊息。 當安裝程式需要關閉應用程式才能完成安裝，或需要重新開機才能完成安裝時，安裝程式會傳送這些訊息。 請注意，在此情況下，應用程式執行復原的時間較少。 例如，應用程式必須在五秒內回應每個訊息。
對於可更新的主控台應用程式，您應該考慮處理CTRL_C_EVENT通知。 如需範例，請參閱 註冊應用程式重新開機。 安裝程式會在需要應用程式關閉才能完成更新時傳送此通知。 應用程式有 30 秒來處理通知。
下列範例示範如何註冊復原、簡單的復原回呼實作，以及如何處理 WM_QUERYENDSESSION 和 WM_ENDSESSION 訊息。
#define UNICODE
#include <windows.h>
#include <stdio.h>
#include <commctrl.h>
#include <strsafe.h>
#include "recover.h"
#pragma comment(lib, "comctl32.lib") // For common controls
#pragma comment(lib, "user32.lib")
#define RESTART_SWITCH L"/restart"
#define RESTART_SWITCH_LEN 8
HINSTANCE g_hinst;
HWND g_hwnd;
HWND g_hwndStatus;
DWORD g_dwRecordId = 0;
// Prototypes
BOOL CreateWindows(void);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
BOOL InitInstance(LPWSTR pwsCommandLine);
DWORD WINAPI Recover(PVOID pContext);
BOOL IsRestartSelected(void);
// A simple example to show how to use application recovery in a window application.
// For simplicity, the state information (record ID) is passed as part of the command line.
int APIENTRY wWinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPWSTR lpCmdLine,
int nCmdShow)
{
MSG msg;
g_hinst = hInstance;
if (!CreateWindows())
{
return 0;
}
if (!InitInstance(lpCmdLine))
{
return 0;
}
ShowWindow(g_hwnd, nCmdShow);
UpdateWindow(g_hwnd);
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int)msg.wParam;
}
// Initialize this instance of the application.
BOOL InitInstance(LPWSTR pwsCommandLine)
{
BOOL fSuccess = TRUE;
BOOL fIsRestart = FALSE;
DWORD len = 0;
LPWSTR pch = NULL;
WCHAR wsStatusMsg[128];
//WCHAR wsCommandLine[RESTART_MAX_CMD_LINE];
if (len = wcslen(pwsCommandLine))
{
// Get the restart info from the command line. The command line is
// of the form, /restart -r:<RecordId>. The application
// is being restarted if the first argument is /restart.
if (!wcsncmp(RESTART_SWITCH, pwsCommandLine, RESTART_SWITCH_LEN))
{
fIsRestart = TRUE;
pch = pwsCommandLine + len;
while (*--pch != ':' && pch >= pwsCommandLine)
;
g_dwRecordId = _wtoi(pch+1);
}
}
if (fIsRestart)
{
// TODO: Use the record ID to initialize the application.
RtlZeroMemory(wsStatusMsg, sizeof(wsStatusMsg));
StringCchPrintf(wsStatusMsg, 128, L"Initializing after restart (record ID is %lu)", g_dwRecordId);
SetWindowText(g_hwndStatus, wsStatusMsg);
}
else
{
// This is not a restart, so initialize the application accordingly.
SetWindowText(g_hwndStatus, L"Initializing application");
}
// You could call the RegisterApplicationRestart and
// RegisterApplicationRecovery functions here to register for
// application recovery and restart, but this example uses menu
// items to toggle these features on and off for testing purposes.
//// Register for restart. The command line is updated in the recovery callback.
//RtlZeroMemory(wsCommandLine, sizeof(wsCommandLine));
//StringCchPrintf(wsCommandLine, RESTART_MAX_CMD_LINE, L"/restart -r:%lu", dwRecordId);
//hr = RegisterApplicationRestart(wsCommandLine, RESTART_NO_PATCH | RESTART_NO_REBOOT);
//if (FAILED(hr))
//{
// // Not failing because the registration failed.
// goto cleanup;
//}
//// Register the callback that handles recovery when the application
//// encounters an unhandled exception or becomes unresponsive.
//hr = RegisterApplicationRecoveryCallback(Recover, g_dwRecordId, RECOVERY_DEFAULT_PING_INTERVAL, 0);
//if (FAILED(hr))
//{
// // Not failing initialization because the registration failed.
// // Consider calling UnregisterApplicationRestart if you must
// // have the latest state information.
// goto cleanup;
//}
//cleanup:
return fSuccess;
}
BOOL CreateWindows(void)
{
BOOL fSuccess = TRUE;
WNDCLASSEX wc;
ATOM atom;
INITCOMMONCONTROLSEX initctrls;
RECT rc;
ZeroMemory(&wc, sizeof(wc));
wc.cbSize = sizeof(wc);
wc.lpfnWndProc = WndProc;
wc.hInstance = g_hinst;
wc.lpszClassName = L"MainWClass";
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.lpszMenuName = MAKEINTRESOURCE(IDC_RECOVER);
atom = RegisterClassEx(&wc);
g_hwnd = CreateWindowEx(0,
L"MainWClass",
L"Testing Application Restart and Recovery",
WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN,
CW_USEDEFAULT, CW_USEDEFAULT,
390, 165,
NULL,
NULL,
g_hinst,
NULL);
if (NULL == g_hwnd)
{
fSuccess = FALSE;
goto cleanup;
}
initctrls.dwSize = sizeof(initctrls);
initctrls.dwICC = ICC_BAR_CLASSES;
InitCommonControlsEx(&initctrls);
GetClientRect(g_hwnd, &rc);
g_hwndStatus = CreateWindowEx(0, STATUSCLASSNAME, NULL,
WS_CHILD | WS_BORDER | WS_VISIBLE,
rc.left, rc.bottom - 20, rc.right, 20,
g_hwnd, NULL, g_hinst, NULL);
if (NULL == g_hwndStatus)
{
fSuccess = FALSE;
}
cleanup:
return fSuccess;
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
HMENU hMenu;
MENUITEMINFO miInfo;
BOOL bChecked = FALSE;
HRESULT hr = S_OK;
int* p = NULL;
ULONG error = ERROR_SUCCESS;
WCHAR wsCommandLine[RESTART_MAX_CMD_LINE];
switch (message)
{
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
// Causes an access violation to test the restart feature,
// if restart is checked. The application must be running
// for at least 60 before it can be restarted if an access
// violation occurs.
case ID_FILE_CRASH:
*p = 5;
break;
// Menu item used to register for restart (checked) and to
// remove the registration (unchecked). The application must be running
// for at least 60 seconds before it can be restarted if an access
// violation occurs (select Crash from the File menu).
case ID_FILE_RESTART:
hMenu = GetMenu(hWnd);
if (hMenu)
{
RtlZeroMemory(&miInfo, sizeof(MENUITEMINFO));
miInfo.cbSize = sizeof(MENUITEMINFO);
miInfo.fMask = MIIM_STATE;
if (GetMenuItemInfo(hMenu, ID_FILE_RESTART, FALSE, &miInfo))
{
// Toggling Restart to unchecked. Remove restart registration.
if ((miInfo.fState & MFS_CHECKED) == MFS_CHECKED)
{
miInfo.fState &= ~MFS_CHECKED;
miInfo.fState |= MFS_UNCHECKED;
hr = UnregisterApplicationRestart();
if (FAILED(hr))
{
// Not failing because removing the registration failed.
}
}
else // Toggling Restart to checked. Register for restart.
{
miInfo.fState &= ~MFS_UNCHECKED;
miInfo.fState |= MFS_CHECKED;
// Register for restart. The command line is updated in the recovery callback,
// if recovery is selected.
RtlZeroMemory(wsCommandLine, sizeof(wsCommandLine));
g_dwRecordId += 10; // Incrementing to show different value on restart.
StringCchPrintf(wsCommandLine, RESTART_MAX_CMD_LINE, L"/restart -r:%lu", g_dwRecordId);
hr = RegisterApplicationRestart(wsCommandLine, RESTART_NO_PATCH | RESTART_NO_REBOOT);
if (FAILED(hr))
{
// Not failing because the registration failed.
}
MessageBox(hWnd, L"You must wait 60 seconds before selecting Crash from the\n"
L"File menu to crash the application and test the restart feature.",
L"Registered for restart",
MB_OK | MB_ICONINFORMATION);
}
if (!SetMenuItemInfo(hMenu, ID_FILE_RESTART, FALSE, &miInfo))
{
// Handle error; call GetLastError() to get the error.
}
}
}
else
{
// Handle error; call GetLastError() to get the error.
}
break;
// Menu item use to register for recovery (checked) and to
// remove the registration (unchecked).
case ID_FILE_RECOVER:
hMenu = GetMenu(hWnd);
if (hMenu)
{
RtlZeroMemory(&miInfo, sizeof(MENUITEMINFO));
miInfo.cbSize = sizeof(MENUITEMINFO);
miInfo.fMask = MIIM_STATE;
if (GetMenuItemInfo(hMenu, ID_FILE_RECOVER, FALSE, &miInfo))
{
if ((miInfo.fState & MFS_CHECKED) == MFS_CHECKED)
{
miInfo.fState &= ~MFS_CHECKED;
miInfo.fState |= MFS_UNCHECKED;
hr = UnregisterApplicationRecoveryCallback();
if (FAILED(hr))
{
// Not failing because removing the registration failed.
}
}
else
{
miInfo.fState &= ~MFS_UNCHECKED;
miInfo.fState |= MFS_CHECKED;
hr = RegisterApplicationRecoveryCallback(Recover, &g_dwRecordId, RECOVERY_DEFAULT_PING_INTERVAL, 0);
if (FAILED(hr))
{
// Not failing because the registration failed.
}
}
if (!SetMenuItemInfo(hMenu, ID_FILE_RECOVER, FALSE, &miInfo))
{
// Handle the error; call GetLastError() to get the error.
}
}
}
else
{
// Handle error; call GetLastError() to get the error.
}
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_CLOSE:
// You could use this message to handle additional recovery
// processing if you are unable to finish recovery in the
// WM_ENDSESSION message. This is for the application update
// case only.
DestroyWindow(hWnd);
break;
// The WM_QUERYENDSESSION and WM_ENDSESSION messages are used for
// recovery only in the case where the application is being updated.
// The recovery callback is used instead for the case where the
// application becomes unresponsive or encounters an unhandled exception.
case WM_QUERYENDSESSION:
// Check the lParam parameter for why the system is asking the application to close.
// The Restart Manager sets lParam to ENDSESSION_CLOSEAPP when installer needs to
// replace files that the application is using.
if (lParam & ENDSESSION_CLOSEAPP)
{
// Consider using EnableWindow to disable the mouse & keyboard input until
// receiving the WM_ENDSESSION message.
// This message is the last opportunity to call the RegisterApplicationRestart
// function to register to have your application restarted after the update
// completes. If you have already registered for restart, you can use this
// opportunity to update the command line arguments.
hr = RegisterApplicationRestart(L"<commandlinearguments>", 0);
if (FAILED(hr))
{
// Log an event or do some error handling.
}
// Typically, applications should respect the user's or system's request and return
// TRUE to indicate that they are willing to close. If the application is performing
// a critical operation which cannot be interrupted, such as burning media, then you
// should return FALSE. If you return FALSE, you should also call the
// ShutdownBlockReasonCreate function to specify a reason for blocking the shutdown
// operation. After the critical operation has completed, call the
// ShutdownBlockReasonDestroy function to indicate that the application is now
// ready to terminate.
return TRUE;
}
return TRUE;
case WM_ENDSESSION:
// You receive this message after receiving the WM_QUERYENDSESSION message. The lParam
// parameter indicates why the system asked the application to close. The Restart
// Manager sets lParam to ENDSESSION_CLOSEAPP when installer needs to replace files
// that the application is using.
if (lParam & ENDSESSION_CLOSEAPP)
{
// You also need to check the value of the wParam parameter. The wParam value
// indicates if the application should close or not based on the results of
// the query. If the value is TRUE, the application is closing.
if (wParam == TRUE)
{
// You should use this opportunity to save data and state information.
}
else // FALSE, the application is not closing
{
// If you disabled the mouse and keyboard input as suggested in
// the WM_QUERYENDSESSION message, you should call the EnableWindow
// function to enable the input.
// You could call the RegisterApplicationRestart function to update the
// command line as appropriate for your application.
hr = RegisterApplicationRestart(L"<commandlinearguments>", 0);
if (FAILED(hr))
{
// Log an event or do some error handling.
}
}
}
return 0;
// This example does not show other messages such as WM_PAINT
// or WM_DESTROY.
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
// Implement the recovery callback. This callback lets the application
// save state information or data in the event that the application
// encounters an unhandled exception or becomes unresponsive.
DWORD WINAPI Recover(PVOID pContext)
{
HRESULT hr = S_OK;
BOOL bCanceled = FALSE;
DWORD dwRecordId = *(DWORD*)pContext;
WCHAR wsCommandLine[RESTART_MAX_CMD_LINE];
// Do recovery work. Save state information.
// Update the restart command line if restart is requested.
if (IsRestartSelected())
{
RtlZeroMemory(wsCommandLine, sizeof(wsCommandLine));
StringCchPrintf(wsCommandLine, RESTART_MAX_CMD_LINE, L"/restart -r:%lu", dwRecordId);
hr = RegisterApplicationRestart(wsCommandLine, RESTART_NO_PATCH | RESTART_NO_REBOOT);
if (FAILED(hr))
{
// Not failing because the registration failed.
wprintf(L"RegisterApplicationRestart failed with ox%x.\n", hr);
}
}
// You must call the ApplicationRecoveryInProgress function within
// the specified ping interval or the recovery callback exits.
// Typically, you would do a block of work, call the function, and repeat.
ApplicationRecoveryInProgress(&bCanceled);
if (bCanceled)
{
wprintf(L"Recovery was canceled by the user.\n");
goto cleanup;
}
cleanup:
ApplicationRecoveryFinished((bCanceled) ? FALSE: TRUE);
return 0;
}
BOOL IsRestartSelected()
{
BOOL fSelected = FALSE;
HMENU hMenu;
MENUITEMINFO miInfo;
hMenu = GetMenu(g_hwnd);
if (hMenu)
{
RtlZeroMemory(&miInfo, sizeof(MENUITEMINFO));
miInfo.cbSize = sizeof(MENUITEMINFO);
miInfo.fMask = MIIM_STATE;
if (GetMenuItemInfo(hMenu, ID_FILE_RESTART, FALSE, &miInfo))
{
if ((miInfo.fState & MFS_CHECKED) == MFS_CHECKED)
fSelected = TRUE;
}
}
return fSelected;
}
以下是復原範例的 recover.h include 檔案。
#pragma once
#include "resource.h"
以下是復原範例的 recover.rc 資源檔。
// Microsoft Visual C++ generated resource script.
//
#include "resource.h"
#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#define APSTUDIO_HIDDEN_SYMBOLS
#include "windows.h"
#undef APSTUDIO_HIDDEN_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
// English (U.S.) resources
#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
#ifdef _WIN32
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#endif //_WIN32
/////////////////////////////////////////////////////////////////////////////
//
// Menu
//
IDC_RECOVER MENU
BEGIN
POPUP "&File"
BEGIN
MENUITEM "C&rash", ID_FILE_CRASH
MENUITEM "&Restart", ID_FILE_RESTART
MENUITEM "Re&cover", ID_FILE_RECOVER
MENUITEM "E&xit", IDM_EXIT
END
END
#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//
1 TEXTINCLUDE
BEGIN
"resource.h\0"
END
2 TEXTINCLUDE
BEGIN
"#define APSTUDIO_HIDDEN_SYMBOLS\r\n"
"#include ""windows.h""\r\n"
"#undef APSTUDIO_HIDDEN_SYMBOLS\r\n"
"\0"
END
3 TEXTINCLUDE
BEGIN
"\r\n"
"\0"
END
#endif // APSTUDIO_INVOKED
#endif // English (U.S.) resources
/////////////////////////////////////////////////////////////////////////////
#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//
/////////////////////////////////////////////////////////////////////////////
#endif // not APSTUDIO_INVOKED
以下是復原範例的 resource.h include 檔案。
//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ generated include file.
// Used by Recover.rc
//
#define IDS_APP_TITLE 103
#define IDM_EXIT 105
#define IDC_RECOVER 109
#define IDR_MAINFRAME 128
#define ID_FILE_CRASH 32771
#define ID_FILE_RESTART 32772
#define ID_FILE_RECOVER 32773
#define IDC_STATIC -1
// Next default values for new objects
//
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NO_MFC 1
#define _APS_NEXT_RESOURCE_VALUE 129
#define _APS_NEXT_COMMAND_VALUE 32774
#define _APS_NEXT_CONTROL_VALUE 1000
#define _APS_NEXT_SYMED_VALUE 110
#endif
#endif