Angular 指令 - 只有数字和 2 位小数，用逗号分隔

Question

I need to allow to only write in an input numbers and optionally 1 comma and 2 decimals.

Example of right inputs:

123
123,22

I've tried this directive I found online but it's allowing me to enter these characters: `, ´, +

Directive code:

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

@Directive({
  selector: '[appTwoDigitDecimaNumber]'
})
export class TwoDigitDecimalNumberDirective {
  // Allow decimal numbers and negative values
  private regex: RegExp = new RegExp(/^\d*\,?\d{0,2}$/g);
  // Allow key codes for special events. Reflect :
  // Backspace, tab, end, home
  private specialKeys: Array<string> = ['Backspace', 'Tab', 'End', 'Home', 'ArrowLeft', 'ArrowRight', 'Del', 'Delete'];

  constructor(private el: ElementRef) {
  }
  @HostListener('keydown', ['$event'])
  onKeyDown(event: KeyboardEvent) {
    console.log(this.el.nativeElement.value);
    // Allow Backspace, tab, end, and home keys
    if (this.specialKeys.indexOf(event.key) !== -1) {
      return;
    }
    let current: string = this.el.nativeElement.value;
    const position = this.el.nativeElement.selectionStart;
    const next: string = [current.slice(0, position), event.key == 'Decimal' ? ',' : event.key, current.slice(position)].join('');
    if (next && !String(next).match(this.regex)) {
      event.preventDefault();
    }
  }
}

What's wrong with this code?

Thanks

Answer 1

JUST CHANGE YOUR INPUT TYPE NUMBER TO TEXT

pipe:

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

@Directive({
  selector: '[appDecimalAmount]'
})
export class DecimalAmountDirective {

  private regex: RegExp = new RegExp(/^\d*\,?\d{0,2}$/g);
  private specialKeys: Array<string> = ['Backspace', 'Tab', 'End', 'Home', 'ArrowLeft', 'ArrowRight', 'Del', 'Delete'];
  constructor(private el: ElementRef) { }
  @HostListener('keydown', ['$event'])
  onKeyDown(event: KeyboardEvent) {
    if (this.specialKeys.indexOf(event.key) !== -1) {
      return;
    }
    const current: string = this.el.nativeElement.value;
    const next: string = current.concat(event.key);
    if (next && !String(next).match(this.regex)) {
      event.preventDefault();

    }
  }
}

HTML

 <label> Cost (&euro;) <sup class="text-danger">*</sup></label>
  <input type="text" formControlName="predictShippingCost" min="0" appDecimalAmount>
``