How To Bind InOutArgument in a Custom Activity


I’m developing a custom activity that takes two arguments, one is an InArgument and the other is an InOutArgument. The second argument is type InOutArgument because I need it to be passed by reference since I use the updated value later in my workflow.

I’ve bound one text box on my custom design to the InArgument so when the InArgument is set in the designer it auto-populates the value in the properties panel and vice versa, working exactly as expected. However, for the InOutArgument if I enter a value in the designer it does not auto-populate to the properties panel, but posting it in properties will auto-populate it into the designer. I would like it to work both ways, since otherwise the activity would be frustrating to use.

I’ve checked the custom activity webinar and its associated source code. I’ve also checked the Community.Activities source code on GitHub. Neither of these dealt specifically with binding to an InOutArgument. I wasn’t able to find anything related to this specific issue on Stack Overflow, either.

How do I configure the custom activity to properly bind an InOutArgument so that updating it in the designer also updates the value in the properties pane?