angular 4 trigger change event dropdown code example
Example: onchange event angular select
-------------For Two Way Data Binding-----------------
<select [ngModel]="selectedDevice" (ngModelChange)="onChange($event)" name="deviceText">
<option [value]="i" *ngFor="let i of devices">{{i}}</option>
</select>
onChange(event){
selectedDevice=event;
-----
-----
}