loops - C# Wait until condition is true -

i trying write code executes when condition met. currently, using while...loop, know not efficient. looking @ autoresetevent() don't know how implement such keeps checking until condition true.

the code happens live inside async method, may kind of await work?

private async void btnok_click(object sender, eventargs e) {         // work         task<string> task = task.run(() => greatbigmethod());         string greatbigmethod = await task;          // wait until condition false         while (!isexcelinteractive())         {             console.writeline("excel busy");         }          // work         console.writeline("yay");  }       private bool isexcelinteractive()     {         try         {             globals.thisworkbook.application.interactive = globals.thisworkbook.application.interactive;             return true; // excel free         }         catch         {             return false; // excel throw exception, meaning busy         }     } 

i need find way keep checking isexcelinteractive() without cpu stuck in loop.

note: there no event handler in excel raised when not in edit mode.

at least can change loop busy-wait slow poll. example:

    while (!isexcelinteractive())     {         console.writeline("excel busy");         await task.delay(25);     }