可以同时使用mat-select和mat-chips吗？

Question

我想知道是否有可能混合使用mat-select和mat-chip-list。在chip-list中，我想显示从mat-select中选择的选项。

如果是，我该怎么做呢？

Answer 1

是的，这是可能的。您需要在<mat-select>中使用<mat-select-trigger>。Inside <mat-select-trigger> place <mat-chip-list>。

在您的HTML模板中，您需要类似以下内容：

<mat-form-field>
  <mat-label>Toppings</mat-label>
  <mat-select [formControl]="toppingsControl" multiple>

    <mat-select-trigger>
      <mat-chip-list>
        <mat-chip *ngFor="let topping of toppingsControl.value"
          [removable]="true" (removed)="onToppingRemoved(topping)">
          {{ topping }}
          <mat-icon matChipRemove>cancel</mat-icon>
        </mat-chip>
      </mat-chip-list>
    </mat-select-trigger>

    <mat-option *ngFor="let topping of toppingList" [value]="topping">{{topping}}</mat-option>

  </mat-select>
</mat-form-field>

<br/> <!-- only for debug -->
{{ toppingsControl.value | json }}

在你的ts中

@Component({
  selector: 'select-multiple-example',
  templateUrl: 'select-multiple-example.html',
  styleUrls: ['select-multiple-example.css'],
})
export class SelectMultipleExample {
  toppingsControl = new FormControl([]);
  toppingList: string[] = ['Extra cheese', 'Mushroom', 'Onion', 'Pepperoni', 'Sausage', 'Tomato'];

  onToppingRemoved(topping: string) {
    const toppings = this.toppingsControl.value as string[];
    this.removeFirst(toppings, topping);
    this.toppingsControl.setValue(toppings); // To trigger change detection
  }

  private removeFirst<T>(array: T[], toRemove: T): void {
    const index = array.indexOf(toRemove);
    if (index !== -1) {
      array.splice(index, 1);
    }
  }

}

Here is a complete example with Angular Material 9, but it works the same in version 6.

我希望这能帮到你!

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Answer 2

您可以通过将选定的值压入一个变量并在mat-chip-list中读取该变量来完成此操作。

HTML：

<mat-form-field>
  <mat-label>Select an option</mat-label>
  <mat-select [(value)]="selected" multiple>
    <mat-option>None</mat-option>
    <mat-option value="option1">Option 1</mat-option>
    <mat-option value="option2">Option 2</mat-option>
    <mat-option value="option3">Option 3</mat-option>
  </mat-select>
</mat-form-field>
<mat-chip-list>
  <mat-chip *ngFor="let value of selected">{{value}}</mat-chip>
</mat-chip-list>

TS：

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

@Component({
  selector: 'my-example',
  templateUrl: 'my-example.html',
  styleUrls: ['my-example.css'],
})
export class MyExample {
  selected: string[] = [];
}

Answer 3

您可以在下面的stackblitz https://stackblitz.com/edit/angular-material-v10-mat-select-with-mat-chip-list-qx5cq-jzc1mi?file=src/app/select-multiple-example.html中找到您的需求的另一个变体