如何使用NG2无效表格注册keyup事件

Question

In NG2, declaratively:
you can use ( keyup.enter ) for registering "press-enter" events. Like this:

<input type="text" #txtEnteredMessage (keyup.enter)="sendMessage(txtEnteredMessage.value);">

In NG2, reactive forms :
I can use the valueChanges observable to listen for changes. But this is not triggered when pressing enter.

How do I register for keyup.enter events using reactive forms (=formcontrol)?

Answer 1

Found a solution that uses Subject:

//inside your hml file 
<input type="text" (keyup.enter)="txtMessageEnter$.next();">

//inside your .ts file
constructor() {       
   this.txtMessageEnter$ = new ReplaySubject<any>();
}
...
this.txtMessageEnter$.subscribe(...)