Button Click event not working in AngularJS 2

Hi all,

Below the code for ts and html file , for this button click

is not working,' please help me,

html

<button mat-button color="primary" (click)="OnAddnepost()">Primary</button>

export class EmpsComponent {
  constructor() { }
  newpost = '';
  OnAddnepost(postinput: HTMLTextAreaElement) {
     console.log(postinput);
  }
}