我如何停止用户的输入0

Question

这是我的OnlyNumber指令，它仅在数字上工作良好。我希望每当用户在输入字段中输入0时，它将转换为1

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

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

  constructor(private el: ElementRef) { }

  @Input() OnlyNumber: boolean;

  @HostListener('keydown', ['$event']) onKeyDown(event) {
    let e = <KeyboardEvent> event;
    console.log(e);
    if (this.OnlyNumber) {
      if ([46, 8, 9, 27, 13, 110, 190].indexOf(e.keyCode) !== -1 ||
        // Allow: Ctrl+A
        (e.keyCode == 65 && e.ctrlKey === true) ||
        // Allow: Ctrl+C
        (e.keyCode == 67 && e.ctrlKey === true) ||
        // Allow: Ctrl+X
        (e.keyCode == 88 && e.ctrlKey === true) ||
        // Allow: Numpad Number
        (e.keyCode >= 96 && e.keyCode <= 105) ||
        // Allow: home, end, left, right
        (e.keyCode >= 35 && e.keyCode <= 39)) {
          // let it happen, don't do anything
          return;
      }
      // Ensure that it is a number and stop the keypress
      if ((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) {
          e.preventDefault();
      }
    }
  }
}

这是我的html输入字段：

<input OnlyNumber='true'  MaxNumber="9" type="text" [(ngModel)]='cart.selectedQty'
                                (ngModelChange)='calculateTotalPrice($event,cart,i)' class="mb-0" />

请给我任何解决方案。

Answer 1

演示供参考：https://stackblitz.com/edit/angular-fndxsq

有关replace的更多信息：https://www.w3schools.com/jsref/jsref_replace.asp