如何从角度8中的ngfor值获取对象计数

Question

我有一张表，其中状态列具有来自对象数组的多个值，在这里我只需要显示2个对象，并且悬停在几个点上可以显示所有对象。现在工作正常，但是当对象计数减少时大于2的点将被隐藏。这是下面的我的代码。

home.component.html

<table class="table border">
    <thead>
        <tr>
            <ng-container *ngFor="let column of columns; let i = index">
                <th>{{ column }}</th>
            </ng-container>
        </tr>
    </thead>
    <tbody>
        <tr *ngFor="let row of groups;let i = index">
            <td>{{row.name}}</td>
            <td>{{row.items}}</td>
            <td >
                <span class="status" *ngFor="let item of row.Status | slice:0:2;let j = index">
                    {{item.name}}
                   </span><span *ngIf = "i < 2" class="dots" (mouseenter) ="onHover(i)" (mouseleave) ="onHover(-1)">.....</span> <span  *ngIf = "i == hoverIndex" class="hover-details"><span  *ngFor="let item of row.Status;let j = index">
                    {{item.name}}
                   </span></span>
           </td>

        </tr>
  </tbody>
</table>

home.component.ts

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
@Component({
  selector: 'app-home',
  templateUrl: './home.component.html',
  styleUrls: ['./home.component.css']
})
export class HomeComponent implements OnInit { 
    dotsh:any;
    hoverIndex:number = -1;
    groups:any;
    test:any;
 constructor(private formBuilder: FormBuilder) {


     }
     onHover(i:number){
 this.hoverIndex = i;
}
     columns = ["name", "Items","status"];



  ngOnInit() {
      this.test = false;
      this.groups=[{"id":1,"name":"pencils","items":"red pencil","Status":[{"id":1,"name":"green"},{"id":2,"name":"red"},{"id":3,"name":"yellow"}],"loc":[{"id":1,"name":"loc 1"},{"id":2,"name":"loc 2"},{"id":3,"name":"loc 3"}]},{"id":2,"name":"rubbers","items":"big rubber","Status":[{"id":1,"name":"green"},{"id":2,"name":"red"}],"loc":[{"id":1,"name":"loc 2"},{"id":2,"name":"loc 3"}]},{"id":3,"name":"rubbers1","items":"big rubber1","Status":[{"id":1,"name":"green"}],"loc":[{"id":1,"name":"loc 2"},{"id":2,"name":"loc 3"}]}];





} 


}

Answer 1

根据您对点i < 2使用的条件，点将从第三行开始隐藏。这不是您想要的。相反，如果Status中的对象数大于1，即使用其length大于2，则要显示点。

<span *ngIf="row.Status.length > 1" class="dots" (mouseenter)="onHover(i)" (mouseleave)="onHover(-1)">.....</span>