Adding Action to Task Sequence via ConfigMgr SDK

Hello again!

I've been doing more work with the ConfigMgr 2012 SP1 SDK and quietly bashing my head against my keyboard...This is probably just due to me not being a coding genius, instead a coding pleb. So, I wanted to figure out how to add an action to a Task Sequence - took a look at the SDK and the code example is as follows:

public IResultObject AddTaskSequenceActionCommandLine(
    WqlConnectionManager connection, 
    IResultObject taskSequence,
    string name, 
    string description)
{
    try
    {
        // Create the new step.
        IResultObject ro;

        ro = connection.CreateEmbeddedObjectInstance("SMS_TaskSequence_RunCommandLineAction");
        ro["CommandLine"].StringValue = @"cmd /c Echo Hello";

        ro["Name"].StringValue = name;
        ro["Description"].StringValue = description;
        ro["Enabled"].BooleanValue = true;
        ro["ContinueOnError"].BooleanValue = false;

        // Add the step to the task sequence.
        List array = taskSequence.GetArrayItems("Steps");

        array.Add(ro);

        taskSequence.SetArrayItems("Steps", array);

        return ro;
    }
    catch (SmsException e)
    {
        Console.WriteLine("Failed to add action: " + e.Message);
        throw;
    }
}

"Oh yeah - that looks pretty easy" I though to myself. But after a lo-o-o-ong time trying to get this working, I was hitting a brick wall. I could get the steps of the task sequence, I could add them to the list, and I could even set the steps to the updated array. Great! However this was not showing up in the Task Sequence. No exceptions were being raised, just nothing happening at all. It seemed like the changes just were not saving, and I guess this is actually what was happening.

So, in ConfigMgr SDK terms, a ConfigMGr Task Sequence (WMI Class: SMS_TaskSequence) and a ConfigMgr Task Sequence Package (WMI Class: SMS_TaskSequencePackage) are two separate items. Modifications to the SMS_TaskSequence object don't do anything UNLESS they are associated to the relevant SMS_TaskSequencePackage.
Now, this might be totally straightforward to you, but it took a bit of head scratching by me to get it. But, get it I did!

public IResultObject AddTaskSequenceActionCommandLine(
    WqlConnectionManager connection, 
    IResultObject taskSequence,
    string name, 
    string description)
{
    try
    {
        // Create the new step.
        IResultObject ro;

        ro = connection.CreateEmbeddedObjectInstance("SMS_TaskSequence_RunCommandLineAction");
        ro["CommandLine"].StringValue = @"cmd /c Echo Hello";

        ro["Name"].StringValue = name;
        ro["Description"].StringValue = description;
        ro["Enabled"].BooleanValue = true;
        ro["ContinueOnError"].BooleanValue = false;

        // Add the step to the task sequence.
        List array = taskSequence.GetArrayItems("Steps");

        array.Add(ro);

        taskSequence.SetArrayItems("Steps", array);

        //Get the relevant Task Sequence Package
        IResultObject tsPackage = connection.GetInstance("SMS_TaskSequencePackage.PackageID='" +
                 pkgID + "'");
        
                Dictionary inParams = new Dictionary();
                inParams.Add("TaskSequence", taskSequence);
                inParams.Add("TaskSequencePackage", tsPackage);

                // Associate the task sequence with the package. 
                IResultObject result = connection.ExecuteMethod("SMS_TaskSequencePackage", "SetSequence", inParams);

        return ro;
    }
    catch (SmsException e)
    {
        Console.WriteLine("Failed to add action: " + e.Message);
        throw;
    }
}

So, I just had to run the SetSequence method on the SMS_TaskSequencePackage class. This method takes parameters of the Task Sequence object, and the Task Sequence package object.Once this was done, the action added without any dramas. Huzzah!

I stress again, this is probably clearly explained somewhere, but pretty hard to find out, hence me sharing this. Hopefully it helps! Let me know in the comments if I've been daft and missed the article that explains this :)