typescript - 如何在角材2中使用垫片和自动完成功能保存所选对象

Question

我正在将Angular 6与Angular Material一起使用。我正在尝试从mat-chip和自动完成功能中保存选定的对象或选定对象的列表。我能够将字符串值发送到fruits []数组，但是无法将所选对象发送到fruits []数组。请帮助我找到解决方案。谢谢。

我的演示项目链接:demo code on stackblitz

Answer 1

您可以尝试此解决方案。

我已经在Stackblitz上创建了一个演示。

component.html

<mat-form-field class="example-chip-list">
    <mat-chip-list #chipList>
        <mat-chip *ngFor="let fruit of fruits;let indx=index;" [selectable]="selectable" [removable]="removable" (removed)="remove(fruit,indx)">
            {{fruit.name}}
            <mat-icon matChipRemove *ngIf="removable">cancel</mat-icon>
        </mat-chip>
        <input placeholder="New fruit..." #fruitInput [formControl]="fruitCtrl" [matAutocomplete]="auto" [matChipInputFor]="chipList"
         [matChipInputSeparatorKeyCodes]="separatorKeysCodes" [matChipInputAddOnBlur]="addOnBlur" (matChipInputTokenEnd)="add($event)">
    </mat-chip-list>
    <mat-autocomplete #auto="matAutocomplete" (optionSelected)="selected($event)">
        <mat-option *ngFor="let fruit of filteredFruits | async" [value]="fruit">
            {{fruit.name}}
        </mat-option>
    </mat-autocomplete>
</mat-form-field>


<pre>{{fruits|json}}</pre>

component.ts

import { COMMA, ENTER } from '@angular/cdk/keycodes';
import { Component, ElementRef, ViewChild } from '@angular/core';
import { FormControl } from '@angular/forms';
import { MatAutocompleteSelectedEvent, MatChipInputEvent } from '@angular/material';
import { Observable } from 'rxjs';
import { map, startWith } from 'rxjs/operators';

/**
 * @title Basic chips
 */
@Component({
  selector: 'chips-overview-example',
  templateUrl: 'chips-overview-example.html',
  styleUrls: ['chips-overview-example.css'],
})
export class ChipsOverviewExample {
  visible = true;
  selectable = true;
  removable = true;
  addOnBlur = false;
  separatorKeysCodes: number[] = [ENTER, COMMA];
  fruitCtrl = new FormControl();
  filteredFruits: Observable<string[]>;
  fruits: any = [];
  allFruits: any = [
    {
      id: 1,
      name: 'Apple'
    },
    {
      id: 2,
      name: 'Orange'
    },
    {
      id: 3,
      name: 'Banana'
    },
    {
      id: 4,
      name: 'Malta'
    }
  ];

  @ViewChild('fruitInput') fruitInput: ElementRef;

  constructor() {
    this.filteredFruits = this.fruitCtrl.valueChanges.pipe(
      startWith(null),
      map((fruit: string | null) => fruit ? this._filter(fruit) : this.allFruits.slice()));
  }

  add(event: MatChipInputEvent): void {
    const input = event.input;
    const value = event.value;
    // Add our fruit
    if ((value || '').trim()) {
      this.fruits.push({
          id:Math.random(),
          name:value.trim()
      });
    }

    // Reset the input value
    if (input) {
      input.value = '';
    }

    this.fruitCtrl.setValue(null);
  }

  remove(fruit, indx): void {
    this.fruits.splice(indx, 1);
  }

  selected(event: MatAutocompleteSelectedEvent): void {
    this.fruits.push(event.option.value);
    this.fruitInput.nativeElement.value = '';
    this.fruitCtrl.setValue(null);
  }

  private _filter(value: any): string[] {
    return this.allFruits.filter(fruit => fruit.id === value.id);
  }
}