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我通过参考官方角度材料示例https://material.angular.io/components/chips/overview#chip-input和https://stackblitz.com/angular/arjnbxmepgn?file=src%2Fapp%mat-chip-list一起使用2Fchips-autocomplete-example.html。上面示例中显示的相同模板在这里 -mat-autocomplete

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

它工作正常，除了以下问题 -

一旦用户关注输入，MatAutoComplete面板就会打开并显示建议。如果用户输入建议中不存在的文本并按下“ENTER”键，则输入的文本在芯片中可见并打开MatAutoComplate面板。MatAutoComplete在这种情况下，我想停止面板的打开。如果用户输入未知文本[即建议中以外的文本]，我不想打开建议面板。在https://stackblitz.com/angular/arjnbxmepgn?file=src%2Fapp%2Fchips-autocomplete-example.html中可以看到相同的情况。

如果用户从建议中选择一个选项并按下“ENTER”键，则MatAutoComplete面板不会打开。当用户在输入中输入未知文本并按下“ENTER”键时，这就是我想要的。

任何帮助将不胜感激。

4

1 回答 1

2

我已将示例更新为：

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

/**
 * @title Chips Autocomplete
 */
@Component({
  selector: 'chips-autocomplete-example',
  templateUrl: 'chips-autocomplete-example.html',
  styleUrls: ['chips-autocomplete-example.css'],
})
export class ChipsAutocompleteExample {
  visible = true;
  selectable = true;
  removable = true;
  separatorKeysCodes: number[] = [ENTER, COMMA];
  fruitCtrl = new FormControl();
  filteredFruits: Observable<string[]>;
  fruits: string[] = ['Lemon'];
  allFruits: string[] = ['Apple', 'Lemon', 'Lime', 'Orange', 'Strawberry'];

  @ViewChild('fruitInput') fruitInput: ElementRef<HTMLInputElement>;
  @ViewChild('auto') matAutocomplete: MatAutocomplete;
  @ViewChild(MatAutocompleteTrigger) autocomplete: MatAutocompleteTrigger;

  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()) {
      if(this.allFruits.indexOf(value) > -1){
       this.fruits.push(value.trim());
      }
    }

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

    this.fruitCtrl.setValue(null);
    this.autocomplete.closePanel();
  }

  remove(fruit: string): void {
    const index = this.fruits.indexOf(fruit);

    if (index >= 0) {
      this.fruits.splice(index, 1);
    }
  }

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

  private _filter(value: string): string[] {
    const filterValue = value.toLowerCase();

    return this.allFruits.filter(fruit => fruit.toLowerCase().indexOf(filterValue) === 0);
  }
}
于 2020-04-25T04:06:32.053 回答