Angular4实现动态添加删除表单输入框功能

<h5>动态添加表单</h5> <div class="form">  <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>  <button (dblclick)="dbclick()">双击</button>  {{ login | json }} </div> 

username: any;  id: number = 1;  login:any = [{"username": "username" + this.id,"password": "pwd" + this.id}];  addInput() {   console.log('点击');   console.log(this.login);   let number = this.login.length + 1;   this.login.push({"username": "username" + number, "password": "pwd" + number});   console.log(this.login);  }  removeInput(item) {   console.log(item);   let i = this.login.indexOf(item);   console.log(i);   this.login.splice(i, 1);  }