ios - How to respond to programmatic changes of a TextView text -

the textview delegate set:

textview.delegate = self //self being uitextviewdelegate 

but delegate method doesn't called when text set programmatically

func textviewdidchange(_ textview: uitextview) {     print(textview.text) } 

how respond text changes without going reactive?

i tried kvo on uitextview,

 self.textview1.text = "you working, change in 5 seconds" 

add observer

self.textview1.addobserver(self, forkeypath: "text", options: nskeyvalueobservingoptions(rawvalue: 0), context: nil) 

trigger text change programmatically, example way want.

 dispatchqueue.main.asyncafter(deadline:.now() + 5) {     self.textview1.text = "changed after time" } 

override kvo method.

override func observevalue(forkeypath keypath: string?, of object: any?, change: [nskeyvaluechangekey : any]?, context: unsafemutablerawpointer?) {     if object == self.textview1{      //do thing here...     } } 

cool works! kvo on uikit works indeed state in apple docs below, fyi.

note: although classes of uikit framework not support kvo, can still implement in custom objects of application, including custom views.

https://developer.apple.com/library/content/documentation/general/conceptual/devpedia-cocoacore/kvo.html