[aus-dotnet] Calling back to JScript from an IE-hosted Winforms Control?

[Douglas Stockwell]

I’m hosting Windows Forms Controls in IE. I want to call back to JScript functions defined in the document to make changes elsewhere when state changes in the control. I can easily call from JScript to my control, but I haven’t been able to find a way to call back or propagate events from my control (when running with the Internet Permission Set).

 

According to this article (http://msdn.microsoft.com/msdnmag/issues/02/01/UserCtrl/default.aspx) it’s possible to do by defining a new COM IDispatch interface and having IE sink that – but that requires permissions to execute unmanaged code.

 

I can pass JScript objects and functions into the control – where they show up as generic COMObject’s. Theoretically I could use IDispatch against these (obj.GetType().InvokeMethod(…)) but once again I don’t have permission to do that.

 

I can pass document elements to the control – these show up as Microsoft.mshtml (GAC assembly) members – but I can’t talk to these either because Microsoft.mshtml doesn’t have AllowPartiallyTrustedCallers set.

 

At the moment I have a workaround where some JScript code polls my control for changes – but this is a hack and pretty undesirable (I don’t want to do busy waiting but I want the results immediately).

 

Any ideas?

 

- Doug