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Why can't set a Variable from an InArgument inside of CacheMetadata?

Posted By:      Posted Date: September 07, 2010    Points: 0   Category :Windows Application
I want to set the defaults for the my arguments and variables the way I see fit. But, this throws an exception. Why?   using System; using System.Activities; using System.Linq.Expressions; namespace ConsoleApplication5 { class Program { static void Main(string[] args) { var wf = new Foo() { }; WorkflowInvoker.Invoke(wf); } } public class Foo : NativeActivity { public InArgument<int> __in { get; set; } public OutArgument<int> __out { get; set; } public Variable<int> __var { get; set; } protected override void CacheMetadata(NativeActivityMetadata metadata) { //provide defaults in this way -> out and variable are equal to in. __in = new InArgument<int>(10); __var = new Variable<int>(context => __in.Get(context)); __out = new OutArgument<int>(context => __in.Get(context)); var rout = new RuntimeArgument("__out", typeof(int), ArgumentDirection.Out); metadata.Bind(__out, rout); var rin = new RuntimeArgument("__in", typeof(int), ArgumentDirection.In); metadata.Bind(__in, rin); metadata.AddImplementationVariable(__var); metadata.AddArgument(rin); metadata.AddArgument(rout); } protected override void Execute(NativeActivityContext context) { } } }   The exception is: System.Activities.InvalidWorkflowException was unhandled   Message=The fol

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