How to list scheduled tasks in C#

Question

Before anyone says this is a duplicate, I already checked here, here, here, here, and a couple of other resources, including MS Task Scheduler Class documentation.

I wanted to be able to list the scheduled tasks on my servers using a C# program I´m developing. Some suggested schtasks.exe MS program, others a third-party library, which seems old and working only with .NET Framework 2.0 and others the MS Task Scheduler Class, which seems to be protected and I´m yet to see some example so I understand how I can use it, and others suggested even reading the XML files in each remote machine under C:\Windows\System32\Tasks folder.

My question is: are tasks in Windows that hard to work with using some VS built-in class? Do I have to jump through hoops in order to do something (kind of) silly like listing the tasks already scheduled in a machine?

Thank you,

EDIT:

I ended up using Process class and started schtasks.exe against all servers. Not exactly what I was looking for but it works. If anyone needs the code, just drop me a line and I post it here. Thanks.

Answer 1

Ah, System.Threading.TaskScheduler is for scheduling work units within a process, not related to the scheduled tasks that you can create from the administrative tools.

I would use a library like TaskScheduler - Googled to find, I do something similar with an awful COM wrapper from 2004 that I've been meaning to update. It makes it pretty easy to see what's in the scheduled tasks.

E.g. from their "Enumerate all tasks" example

void EnumAllTasks()
{
   using (TaskService ts = new TaskService())
      EnumFolderTasks(ts.RootFolder);
}

void EnumFolderTasks(TaskFolder fld)
{
   foreach (Task task in fld.Tasks)
      ActOnTask(task);
   foreach (TaskFolder sfld in fld.SubFolders)
      EnumFolderTasks(sfld);
}

void ActOnTask(Task t)
{
   // Do something interesting here
}

Answer 2

In Visual Studio add the reference in COM\Type Libraries: TaskScheduler

and use the Taskschd API: https://docs.microsoft.com/en-us/windows/desktop/api/taskschd

This is an example of the way I'm doing it:

You retrieve the tasks at which you have access permissions, depending if you're running the code with a local or admin account.

My solution was doing this in a Windows Service with Local System account that runs in our servers.

using TaskScheduler;

void ProcessTaskFoler (ITaskFolder taskFolder)
{
    int idx;
    string name, path;
    _TASK_STATE state;

    IRegisteredTaskCollection taskCol = taskFolder.GetTasks((int)_TASK_ENUM_FLAGS.TASK_ENUM_HIDDEN);  // include hidden tasks, otherwise 0
    for (idx = 1; idx <= taskCol.Count; idx++)  // browse al tasks in folder
    {
        IRegisteredTask runTask = taskCol[idx];  // 1 based index

        name = runTask.Name;
        path = runTask.Path;
        state = runTask.State;
        // retrieve other properties...

        Console.WriteLine(path);
    }

    ITaskFolderCollection taskFolderCol = taskFolder.GetFolders(0);  // 0 = reserved for future use
    for (idx = 1; idx <= taskFolderCol.Count; idx++)  // recursively browse subfolders
        ProcessTaskFoler(taskFolderCol[idx]);  // 1 based index
}

void ParseScheduleTasks()
{
    ITaskService taskService = new TaskScheduler.TaskScheduler();
    taskService.Connect();

    ProcessTaskFoler(taskService.GetFolder("\\"));
}