angular 管道

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'multi'
})
export class MultiPipe implements PipeTransform {

  transform(value: any, args?: any): any {
    if (args == null) {
      args = ;
    }
    return value * args;
  }

}

<div>我的生日{{birth | date | uppercase}}</div>
<div>我的生日{{birth | date :'yyyy-MM-dd'}}</div>
<div>我的生日{{numberA | number :'2.1-4'}}</div>

<div>我的生日{{numberA | multi :}}</div>

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-bind',
  templateUrl: './bind.component.html',
  styleUrls: ['./bind.component.css']
})
export class BindComponent implements OnInit {

  private birth: Date;

  private numberA: number;

  constructor() { }

  ngOnInit() {
    this.birth = new Date();
    this.numberA = 3.1514926;
  }
}