C/C++ Code Example: Retrieving a Task Page
This example retrieves and displays the Task page of a known task. Note that in this example, all interfaces are released when they are no longer needed.
#include <windows.h>
#include <initguid.h>
#include <ole2.h>
#include <mstask.h>
#include <msterr.h>
#include <wchar.h>
int main(int argc, char **argv)
{
HRESULT hr = S_OK;
///////////////////////////////////////////////////////////////////
// Call CoInitialize to initialize the COM library and then
// call CoCreateInstance to get the Task Scheduler object.
///////////////////////////////////////////////////////////////////
ITaskScheduler *pITS;
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;
}
///////////////////////////////////////////////////////////////////
// Call ITaskScheduler::Activate to get the Task object.
///////////////////////////////////////////////////////////////////
ITask *pITask;
LPCWSTR lpcwszTaskName = L"Test Task";
hr = pITS->Activate(lpcwszTaskName,
IID_ITask,
(IUnknown**) &pITask);
// Release the ITaskScheduler interface.
pITS->Release();
if (FAILED(hr))
{
wprintf(L"Failed calling ITaskScheduler::Activate: ");
wprintf(L"error = 0x%x\n",hr);
CoUninitialize();
return 1;
}
///////////////////////////////////////////////////////////////////
// Call ITask::QueryInterface to retrieve the IProvideTaskPage
// interface, and call IProvideTaskPage::GetPage to retrieve the
// task page.
///////////////////////////////////////////////////////////////////
TASKPAGE tpType = TASKPAGE_TASK;
BOOL fPersistChanges = TRUE;
HPROPSHEETPAGE phPage;
IProvideTaskPage *pIProvTaskPage;
hr = pITask->QueryInterface(IID_IProvideTaskPage,
(void **)&pIProvTaskPage);
// Release the ITask interface.
pITask->Release();
if (FAILED(hr))
{
wprintf(L"Failed calling ITask::QueryInterface: ");
wprintf(L"error = 0x%x\n",hr);
CoUninitialize();
return 1;
}
hr = pIProvTaskPage->GetPage(tpType,
fPersistChanges,
&phPage);
// Release the IProvideTaskPage interface.
pIProvTaskPage->Release();
if (FAILED(hr))
{
wprintf(L"Failed calling IProvideTaskPage::GetPage: ");
wprintf(L"error = 0x%x\n",hr);
CoUninitialize();
return 1;
}
//////////////////////////////////////////////////////////////////
// Display the page using additional code.
//////////////////////////////////////////////////////////////////
PROPSHEETHEADER psh;
ZeroMemory(&psh, sizeof(PROPSHEETHEADER));
psh.dwSize = sizeof(PROPSHEETHEADER);
psh.dwFlags = PSH_DEFAULT | PSH_NOAPPLYNOW;
psh.phpage = &phPage;
psh.nPages = 1;
int psResult = PropertySheet(&psh);
if (psResult <= 0)
{
wprintf(L"Failed to create the property page: ");
wprintf(L"0x%x\n", GetLastError());
}
CoUninitialize();
return 0;
}
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