Task scheduler created in C++ could not be started
I created an scheduler in C++.I have set all the parameters and the task is configured to run only when the user is logged on with the user name provided(Done by setting the TASK_FLAG_RUN_ONLY_IF_LOGGED_ON flag).
When I try to run the task I get a status "Could not start". Now suppose I manually edit any property in task property and click on OK the task runs fine.
Note:The manual edit specified may be anything, like just adding a space at the end of the excecutable name or the user name. What may be the problem?
Below is the code i am using:
#include <windows.h>
#include <initguid.h>
#include <ole2.h>
#include <mstask.h>
#include <msterr.h>
#include <wchar.h>
#include<stdio.h>
#include<conio.h>
#pragma comment(lib, "Mstask.lib")
#pragma comment(lib, "ole32.lib")
int main(int argc, char **argv)
{
HRESULT hr = S_OK;
ITaskScheduler *pITS;
///////////////////////////////////////////////////////////////////
// Call CoInitialize to initialize the COM library and then
// CoCreateInst开发者_C百科ance to get the Task Scheduler object.
///////////////////////////////////////////////////////////////////
hr = CoInitialize(NULL);
if (SUCCEEDED(hr))
{
hr = CoCreateInstance(CLSID_CTaskScheduler,
NULL,
CLSCTX_INPROC_SERVER,
IID_ITaskScheduler,
(void **) &pITS);
if (FAILED(hr))
{
CoUninitialize();
return 1;
}
}
else
{
return 1;
}
LPCWSTR pwszTaskName;
ITask *pITask;
pwszTaskName = L"TestTask";
hr = pITS->NewWorkItem(pwszTaskName,
CLSID_CTask,
IID_ITask,
(IUnknown**)&pITask);
if (FAILED(hr))
{
wprintf(L"Failed calling ITaskScheduler::NewWorkItem: ");
wprintf(L"error = 0x%x\n",hr);
CoUninitialize();
return 1;
}
LPCWSTR pwszApplicationName = L"C:\\windows\\notepad.exe";
hr = pITask->SetApplicationName(pwszApplicationName);
if (FAILED(hr))
{
wprintf(L"Failed calling ITask::SetApplicationName: ");
wprintf(L"error = 0x%x\n",hr);
pITS->Release();
pITask->Release();
CoUninitialize();
return 1;
}
pITask->SetAccountInformation(L"USERNAME", NULL);
pITask->SetFlags(TASK_FLAG_RUN_ONLY_IF_LOGGED_ON);
pITask->SetWorkingDirectory(L"C:\\windows");
ITaskTrigger *pITaskTrigger;
WORD piNewTrigger;
hr = pITask->CreateTrigger(&piNewTrigger,
&pITaskTrigger);
if (FAILED(hr))
{
wprintf(L"Failed calling ITask::CreatTrigger: ");
wprintf(L"error = 0x%x\n",hr);
pITask->Release();
CoUninitialize();
return 1;
}
pITS->AddWorkItem(pwszTaskName, pITask);
pITS->Release(); // Release sceduler
hr = pITask->Run();
if (FAILED(hr))
{
wprintf(L"Failed calling ITask::Run, error = 0x%x\n",hr);
pITask->Release();
CoUninitialize();
return 1;
}
pITask->Release();
CoUninitialize();
_getch();
return 0;
}
I think you need to test all return values, that could be revealing. I'm mostly suspicious about:
pITask->SetAccountInformation(L"USERNAME", NULL);
pITask->SetFlags(TASK_FLAG_RUN_ONLY_IF_LOGGED_ON);
Readinig http://msdn.microsoft.com/en-us/library/aa381276(VS.85).aspx I got the impression that you need to call SetFlags first and then SetAccountInformation.
I've had the same problem on XP: status "Could not start" and all ok after manual editing. Solution:
- Go to Advanced -> View Log. And see the reason for the fail.
- In my case there was "The attempt to retrieve account information for the specified task failed". So I've just needed to get user name via
GetUserName
and set it viaSetAccountInformation
. Note order ofSetAccountInformation
andSetFlags
doesn't matter. - Take a look here for other reasons.
May be it will help someone someday.
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