I am running Excel as a calculation engine (no user interaction) through VSTO and would like to be able to cancel a long running macro programmatically.
My current approach is to put the blocking call to run the Macro (Application.Run("MyMacro")) on a separate thread and then attempt to interrupt it from the main thread.
There does not seem to be any in built method call for this purpose such as Application.Interrupt(), so I am trying to programmatically trigger the keyboard interrupt that occurs when CTRL+Break or ESC are pressed.
Current code looks like:
Application.CalculationInterruptKey = XlCalculationInterruptKey.xlAnyKey;
Application.EnableCancelKey = XlEnableCancelKey.xlInterrupt;
Application.SendKeys("{ESC}", false); //have tried with true as second argument
In this case the code blocks on the final line which does not execute until the macro has completed.
I have also tried obtaining the process hook for Excel, setting it as the active process / window and calling SendKeys without success.
As this needs to be a generic solution for executing any macro, I cannot modify or provide any guarantees as to the macro contents.
Any ideas?
Thanks,
PS I have also tried sending the CTRL+BREAK keyboard command as in Application.SendKeys("^{BREAK}", false); The debugger pauses on this line until the macro finishes execution, so it seems like the Application object is blocked from processing any more commands until the macro has completed.
