<div class="form-group form-group-sm" *ngFor="let i of login">

     <label class="col-form-label">用户名</label>

     <input class="form-control" [(ngModel)]="i.username" value="{{i.username}}">

     <label class="col-form-label">密码</label>

     <input class="form-control" [(ngModel)]="i.password" value="{{i.password}}">

     <button class="btn btn-link" (click)="removeInput(i)">删除</button>

   </div>

   <button (click)="addInput()">增加</button>

 private id: string;

   login: any = [{ 'username': 'username' + this.id, 'password': 'pwd' + this.id }];

   addInput() {

     console.log('点击');

     console.log(this.login);

     const number = this.login.length + 1;

     this.login.push({ 'username': 'username' + number, 'password': 'pwd' + number });

     console.log(this.login);

   }

   removeInput(item) {

     console.log(item);

     const i = this.login.indexOf(item);

     console.log(i);

     this.login.splice(i, 1);

   }