每周触发器示例 (C++)

此 C++ 示例演示如何创建计划每周执行记事本的任务。 该任务包含一个每周触发器,该触发器指定开始时间的开始边界、周间隔和一周中的一天。 该任务还包含指定要执行记事本的任务的操作。

以下过程介绍如何计划任务每周启动可执行文件。

计划每周启动记事本

  1. 初始化 COM 并设置常规 COM 安全性。

  2. 创建 ITaskService 对象。

    此对象允许在指定文件夹中创建任务。

  3. 获取任务文件夹以在其中创建任务。

    使用 ITaskService::GetFolder 方法获取文件夹,使用 ITaskService::NewTask 方法创建 ITaskDefinition 对象。

  4. 使用 ITaskDefinition 对象定义有关任务的信息,例如任务的注册信息。

    使用 ITaskDefinition 的 RegistrationInfo 属性ITaskDefinition 接口的其他属性定义任务信息。

  5. 使用 ITaskDefinition 的 Triggers 属性 创建每周触发器,以访问任务的 ITriggerCollection 接口。

    使用 ITriggerCollection::Create 方法指定要创建每周触发器。 可以设置 IWeeklyTrigger 触发器的开始边界、周间隔和星期几,以便任务的操作计划在一周中的某一天执行。

  6. 使用 ITaskDefinition 的 Actions 属性 访问任务的 IActionCollection 接口,为任务创建一个操作。

    使用 IActionCollection::Create 方法指定要创建的操作类型。 此示例使用 IExecAction 对象,该对象表示执行命令行操作的操作。

  7. 使用 ITaskFolder::RegisterTaskDefinition 方法注册任务。

以下 C++ 示例演示如何计划每周执行记事本的任务。

/********************************************************************
 This sample schedules a task to start on a weekly basis. 
********************************************************************/

#define _WIN32_DCOM

#include <windows.h>
#include <iostream>
#include <stdio.h>
#include <comdef.h>
#include <wincred.h>
//  Include the task header file.
#include <taskschd.h>
#pragma comment(lib, "taskschd.lib")
#pragma comment(lib, "comsupp.lib")
#pragma comment(lib, "credui.lib")

using namespace std;


void main(void)
{
    //  ------------------------------------------------------
    //  Initialize COM.
    HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
    if( FAILED(hr) )
    {
        printf("\nCoInitializeEx failed: %x", hr );
        return;
    }

    //  Set general COM security levels.
    hr = CoInitializeSecurity(
        NULL,
        -1,
        NULL,
        NULL,
        RPC_C_AUTHN_LEVEL_PKT,
        RPC_C_IMP_LEVEL_IMPERSONATE,
        NULL,
        0,
        NULL);

    if( FAILED(hr) )
    {
        printf("\nCoInitializeSecurity failed: %x", hr );
        CoUninitialize();
        return;
    }

    //  ------------------------------------------------------
    //  Create a name for the task.
    LPCWSTR wszTaskName = L"Weekly Trigger Task";

    //  Get the windows directory and set the path to notepad.exe.
    wstring wstrExecutablePath = _wgetenv( L"WINDIR");
    wstrExecutablePath += L"\\SYSTEM32\\NOTEPAD.EXE";


    //  ------------------------------------------------------
    //  Create an instance of the Task Service. 
    ITaskService *pService = NULL;
    hr = CoCreateInstance( CLSID_TaskScheduler,
                           NULL,
                           CLSCTX_INPROC_SERVER,
                           IID_ITaskService,
                           (void**)&pService );  
    if (FAILED(hr))
    {
          printf("Failed to create an instance of ITaskService: %x", hr);
          CoUninitialize();
          return;
    }
        
    //  Connect to the task service.
    hr = pService->Connect(_variant_t(), _variant_t(),
        _variant_t(), _variant_t());
    if( FAILED(hr) )
    {
        printf("ITaskService::Connect failed: %x", hr );
        pService->Release();
        CoUninitialize();
        return;
    }

    //  ------------------------------------------------------
    //  Get the pointer to the root task folder.  
    //  This folder will hold the new task that is registered.
    ITaskFolder *pRootFolder = NULL;
    hr = pService->GetFolder( _bstr_t( L"\\") , &pRootFolder );
    if( FAILED(hr) )
    {
        printf("Cannot get Root Folder pointer: %x", hr );
        pService->Release();
        CoUninitialize();
        return;
    }
    
    //  If the same task exists, remove it.
    pRootFolder->DeleteTask( _bstr_t( wszTaskName), 0  );
    
    //  Create the task builder object to create the task.
    ITaskDefinition *pTask = NULL;
    hr = pService->NewTask( 0, &pTask );
    
    pService->Release();  // COM clean up.  Pointer is no longer used.
    if (FAILED(hr))
    {
          printf("Failed to create a task definition: %x", hr);
          pRootFolder->Release();
          CoUninitialize();
          return;
    }
            
    //  ------------------------------------------------------
    //  Get the registration info for setting the identification.
    IRegistrationInfo *pRegInfo= NULL;
    hr = pTask->get_RegistrationInfo( &pRegInfo );
    if( FAILED(hr) )
    {
        printf("\nCannot get identification pointer: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }
    
    hr = pRegInfo->put_Author( L"Author Name" );
    pRegInfo->Release();  // COM clean up.  Pointer is no longer used.
    if( FAILED(hr) )
    {
        printf("\nCannot put identification info: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }
    
    //  ------------------------------------------------------
    //  Get the trigger collection to insert the weekly trigger.
    ITriggerCollection *pTriggerCollection = NULL;
    hr = pTask->get_Triggers( &pTriggerCollection );
    if( FAILED(hr) )
    {
        printf("\nCannot get trigger collection: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }
        
    ITrigger *pTrigger = NULL;
    hr = pTriggerCollection->Create( TASK_TRIGGER_WEEKLY, &pTrigger );     
    pTriggerCollection->Release();
    if( FAILED(hr) )
    {
        printf("\nCannot create the trigger: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }

    IWeeklyTrigger *pWeeklyTrigger = NULL;
    hr = pTrigger->QueryInterface( 
            IID_IWeeklyTrigger, (void**) &pWeeklyTrigger );
    pTrigger->Release();
    if( FAILED(hr) )
    {
        printf("\nQueryInterface call for IWeeklyTrigger failed: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }
    
    hr = pWeeklyTrigger->put_Id( _bstr_t( L"Trigger1" ) );
    if( FAILED(hr) )
        printf("\nCannot put trigger ID: %x", hr);

    //  Set the task to start weekly at a certain time. The time 
    //  format should be YYYY-MM-DDTHH:MM:SS(+-)(timezone).
    //  For example, the start boundary below is January 1st 2005 at
    //  12:05
    hr = pWeeklyTrigger->put_StartBoundary( _bstr_t(L"2005-01-01T12:05:00") );
    if( FAILED(hr) )
        printf("\nCannot put the start boundary: %x", hr);

    //  Set the time when the trigger is deactivated.
    hr = pWeeklyTrigger->put_EndBoundary( _bstr_t(L"2007-01-01T12:05:00") );
    if( FAILED(hr) )
        printf("\nCannot put the end boundary: %x", hr);
    
    
    //  Define the interval for the weekly trigger. 
    //  An interval of 2 produces an
    //  every other week schedule
    hr = pWeeklyTrigger->put_WeeksInterval( (short)2 );
    if( FAILED(hr) )
    {
        printf("\nCannot put weeks interval: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }
    
    hr = pWeeklyTrigger->put_DaysOfWeek( (short)2 );    // Runs on Monday
    pWeeklyTrigger->Release();
    if( FAILED(hr) )
    {
        printf("\nCannot put days of week interval: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }

    //  ------------------------------------------------------
    //  Add an Action to the task. This task will execute notepad.exe.     
    IActionCollection *pActionCollection = NULL;

    //  Get the task action collection pointer.
    hr = pTask->get_Actions( &pActionCollection );
    if( FAILED(hr) )
    {
        printf("\nCannot get Task collection pointer: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }
        
    //  Create the action, specifying that it is an executable action.
    IAction *pAction = NULL;
    hr = pActionCollection->Create( TASK_ACTION_EXEC, &pAction );
    pActionCollection->Release();
    if( FAILED(hr) )
    {
        printf("\nCannot create the action: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }

    IExecAction *pExecAction = NULL;
    //  QI for the executable task pointer.
    hr = pAction->QueryInterface( 
        IID_IExecAction, (void**) &pExecAction );
    pAction->Release();
    if( FAILED(hr) )
    {
        printf("\nQueryInterface call failed on IExecAction: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }

    //  Set the path of the executable to notepad.exe.
    hr = pExecAction->put_Path( _bstr_t( wstrExecutablePath.c_str() ) );
    pExecAction->Release();
    if( FAILED(hr) )
    {
        printf("\nCannot add path for executable action: %x", hr );
        pRootFolder->Release();
        pTask->Release();
        CoUninitialize();
        return;
    }

    //  ------------------------------------------------------
    //  Securely get the user name and password. The task will
    //  be created to run with the credentials from the supplied 
    //  user name and password.
    CREDUI_INFO cui;
    TCHAR pszName[CREDUI_MAX_USERNAME_LENGTH] = "";
    TCHAR pszPwd[CREDUI_MAX_PASSWORD_LENGTH] = "";
    BOOL fSave;
    DWORD dwErr;

    cui.cbSize = sizeof(CREDUI_INFO);
    cui.hwndParent = NULL;
    //  Ensure that MessageText and CaptionText identify
    //  what credentials to use and which application requires them.
    cui.pszMessageText = TEXT("Account information for task registration:");
    cui.pszCaptionText = TEXT("Enter Account Information for Task Registration");
    cui.hbmBanner = NULL;
    fSave = FALSE;

    //  Create the UI asking for the credentials.
    dwErr = CredUIPromptForCredentials(
        &cui,                             //  CREDUI_INFO structure
        TEXT(""),                         //  Target for credentials
        NULL,                             //  Reserved
        0,                                //  Reason
        pszName,                          //  User name
        CREDUI_MAX_USERNAME_LENGTH,       //  Max number for user name
        pszPwd,                           //  Password
        CREDUI_MAX_PASSWORD_LENGTH,       //  Max number for password
        &fSave,                           //  State of save check box
        CREDUI_FLAGS_GENERIC_CREDENTIALS |  //  Flags
        CREDUI_FLAGS_ALWAYS_SHOW_UI |
        CREDUI_FLAGS_DO_NOT_PERSIST);  

    if(dwErr)
    {
        cout << "Did not get credentials." << endl;    
        CoUninitialize();
        return;      
    }

    
    //  ------------------------------------------------------
    //  Save the task in the root folder.
    IRegisteredTask *pRegisteredTask = NULL;
    hr = pRootFolder->RegisterTaskDefinition(
            _bstr_t( wszTaskName ),
            pTask,
            TASK_CREATE_OR_UPDATE, 
            _variant_t(_bstr_t(pszName)), 
            _variant_t(_bstr_t(pszPwd)), 
            TASK_LOGON_PASSWORD,
            _variant_t(L""),
            &pRegisteredTask);
    if( FAILED(hr) )
    {
        printf("\nError saving the Task : %x", hr );
        pRootFolder->Release();
        pTask->Release();
        SecureZeroMemory(pszName, sizeof(pszName));
        SecureZeroMemory(pszPwd, sizeof(pszPwd));
        CoUninitialize();
        return;
    }

    printf("\n Success! Task succesfully registered. " );

    //  Clean up
    pRootFolder->Release();
    pTask->Release();
    pRegisteredTask->Release();
    SecureZeroMemory(pszName, sizeof(pszName));
    SecureZeroMemory(pszPwd, sizeof(pszPwd));
    CoUninitialize();
    return;
}

使用任务计划程序