TFS Build 2013 - Variable scope and custom activities - tfs

Question

I was trying to do something similar to the stackoverflow article referenced below and am finding I can't set values in the code activity. I seem to be able to read values OK. I suspect this has something to do with the scope of these. In the stackoverflow article the code implied that the variable was set for the loop,
I am after guidance on how to set these correctly or a way for my codeactivity to flag to exit the external DoWhile loop ?
Refs
StackOverflow Article
Code Activity article

Answer 1

OK here is the missing story and is not in the MS doco that I have found..
e.g. https://msdn.microsoft.com/en-us/library/dd647551(v=vs.120).aspx
Although MS document In, InOut, Out args their scope is not shared... i.e.
WRONG View of the world
XAML argument like MyBoolInOut Inout is the same argument that the C# code is using , e.g.
public InOutArgument MyBoolInOut { get; set; }
thus you only need to change values in C# code to change the values in the TFS XAML
Correct view of this handling
The custom code activity variables are visible in the XAML BUT are different from the XAML arguments. i.e.
as below, your C# codeactivity args have to be manually linked to the XAML args
So even though XAML has arguments and C# have arguments, these are separate.
This is an area MS could greatly improve their doco in.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
using Microsoft.TeamFoundation.Build.Client;
using Microsoft.TeamFoundation.Client;
using Microsoft.TeamFoundation.TestManagement.Client;
using Microsoft.TeamFoundation.Build.Workflow.Activities;
namespace SampleActivityLibrary
{
[BuildActivity(HostEnvironmentOption.All)]
// Sample Acitivty that will Flip a bool from True to False or from False to True
public sealed class SampleFlipInOutBoolean : CodeActivity<Boolean>
{
public InOutArgument<Boolean> MyBoolInOut { get; set; }
protected override Boolean Execute(CodeActivityContext context)
{
Boolean MyBool = context.GetValue(MyBoolInOut);
context.TrackBuildWarning("SampleFlipInOutBoolean: In Value of Bool: " + MyBool.ToString(), BuildMessageImportance.High);
MyBoolInOut.Set(context, !MyBool);
MyBool = context.GetValue(MyBoolInOut);
context.TrackBuildWarning("SampleFlipInOutBoolean: Out Value of Bool: " + MyBool.ToString(), BuildMessageImportance.High);
return MyBool;
}
}
}