具有角度材料的角度 4 中具有不同来源的同一页面中的多个自动完成

Question

在同一页面中使用角度 4 中不同来源的多个自动完成功能：

来源：https://material.angular.io/components/autocomplete/examples

我遵循了材料自动完成示例，并尝试在同一页面中再添加一个自动完成，但来源不同但无法正常工作。

formcontrol 有问题吗？？

import {Component} from '@angular/core';
import {FormControl} from '@angular/forms';

import 'rxjs/add/operator/startWith';
import 'rxjs/add/operator/map';

@Component({
  selector: 'autocomplete-overview-example',
  templateUrl: 'autocomplete-overview-example.html',
})
export class AutocompleteOverviewExample {
  stateCtrl: FormControl;
  testCtrl: FormControl;
  filteredStates: any;
  filterTests:any;
tests = [
    'Nawab',
    'Alaska',
    'Arizona',
    'Arkansas',
    'California'];
  states = [
    'Alabama',
    'Alaska',
    'Arizona',
    'Arkansas',
    'California',
    'Colorado',
    'Connecticut',
    'Delaware',
    'Florida',
    'Georgia',
    'Hawaii',
    'Idaho',
    'Illinois',
    'Indiana',
    'Iowa',
    'Kansas',
    'Kentucky',
    'Louisiana',
    'Maine',
    'Maryland',
    'Massachusetts',
    'Michigan',
    'Minnesota',
    'Mississippi',
    'Missouri',
    'Montana',
    'Nebraska',
    'Nevada',
    'New Hampshire',
    'New Jersey',
    'New Mexico',
    'New York',
    'North Carolina',
    'North Dakota',
    'Ohio',
    'Oklahoma',
    'Oregon',
    'Pennsylvania',
    'Rhode Island',
    'South Carolina',
    'South Dakota',
    'Tennessee',
    'Texas',
    'Utah',
    'Vermont',
    'Virginia',
    'Washington',
    'West Virginia',
    'Wisconsin',
    'Wyoming',
  ];

  constructor() {
    this.stateCtrl = new FormControl();
    this.filteredStates = this.stateCtrl.valueChanges
        .startWith(null)
        .map(name => this.filterStates(name));
        this.testCtrl = new FormControl();
    this.filteredTests = this.testCtrl.valueChanges
        .startWith(null)
        .map(name => this.filterTests(name));
  }

  filterStates(val: string) {
    return val ? this.states.filter(s => s.toLowerCase().indexOf(val.toLowerCase()) === 0)
               : this.states;
  }
  filterTests(val: string) {
    return val ? this.tests.filter(s => s.toLowerCase().indexOf(val.toLowerCase()) === 0)
               : this.tests;
  }

}


/**  Copyright 2017 Google Inc. All Rights Reserved.
    Use of this source code is governed by an MIT-style license that
    can be found in the LICENSE file at http://angular.io/license */

<md-input-container>
  <input mdInput placeholder="State" [mdAutocomplete]="auto" [formControl]="stateCtrl">
</md-input-container>

<md-autocomplete #auto="mdAutocomplete">
  <md-option *ngFor="let state of filteredStates | async" [value]="state">
    {{ state }}
  </md-option>
</md-autocomplete>
<md-input-container>
  <input mdInput placeholder="Test" [mdAutocomplete]="auto" [formControl]="testCtrl">
</md-input-container>

<md-autocomplete #auto="mdAutocomplete">
  <md-option *ngFor="let test of filteredTests | async" [value]="test">
    {{ test }}
  </md-option>
</md-autocomplete>

Answer 1

您为两个输入分配了相同的参考变量 (#auto)。每个输入的 id 必须是唯一的。将您的第二个 input 和 md-autocomplete 更改为以下内容：

<md-input-container>
  <input mdInput placeholder="Test" [mdAutocomplete]="autoTest" [formControl]="testCtrl">
</md-input-container>
<md-autocomplete #autoTest="mdAutocomplete">
  <md-option *ngFor="let test of filteredTests | async" [value]="test">
    {{ test }}
  </md-option>
</md-autocomplete>

链接到Plunker Demo

---

对于像*ngFor 这样的循环，不需要创建动态命名的模板变量，因为

模板引用变量的范围仅限于它们所在的模板 定义在。结构指令创建一个嵌套模板，并且， 因此，引入了一个单独的范围。 (This question)