hostbindingcode1.js

import { Directive, ElementRef, Renderer } from '@angular/core';

@Directive({
    selector: '[appChbgcolor]'
})
export class ChangeBgColorDirective {

    constructor(private el: ElementRef, private renderer: Renderer) {
        this.ChangeBgColor('red');
    }

    ChangeBgColor(color: string) {

        this.renderer.setElementStyle(this.el.nativeElement, 'color', color);
    }
}