1import { Directive, ElementRef, HostListener } from '@angular/core';
2@Directive({
3  selector: '[appTwoDigitDecimaNumber]'
4})
5export class TwoDigitDecimaNumberDirective {
6  private regex: RegExp = new RegExp(/^\d*\.?\d{0,2}$/g);
7  private specialKeys: Array<string> = ['Backspace', 'Tab', 'End', 'Home', '-', 'ArrowLeft', 'ArrowRight', 'Del', 'Delete'];
8  constructor(private el: ElementRef) {
9  }
10  @HostListener('keydown', ['$event'])
11  onKeyDown(event: KeyboardEvent) {
12    console.log(this.el.nativeElement.value);
13    // Allow Backspace, tab, end, and home keys
14    if (this.specialKeys.indexOf(event.key) !== -1) {
15      return;
16    }
17    let current: string = this.el.nativeElement.value;
18    const position = this.el.nativeElement.selectionStart;
19    const next: string = [current.slice(0, position), event.key == 'Decimal' ? '.' : event.key, current.slice(position)].join('');
20    if (next && !String(next).match(this.regex)) {
21      event.preventDefault();
22    }
23  }
24}

1<input type="textbox" [(ngModel)]="InputValue" appTwoDigitDecimaNumber>