您可以使用MatAutocomplete 和一些技巧来实现自动完成多选。我很确定你不能用MatSelect 做到这一点，因为这不能让你控制输入元素。该技术有点奇怪，但效果很好。这个想法是管理控制器中的选择，并将每个mat-option 的“值”设置为相同的东西 - 您选择的选项。您还需要捕获单击以允许用户与列表交互（而不是在单击时立即关闭），当然还需要在 mat-option 项目中提供复选框。其他一些技巧也是必要的 - here is a quick and dirty example 显示了该做什么。
HTML：
<mat-form-field class="example-full-width">
<input type="text" placeholder="Select Users" aria-label="Select Users" matInput [matAutocomplete]="auto" [formControl]="userControl">
<mat-hint>Enter text to find users by name</mat-hint>
</mat-form-field>
<mat-autocomplete #auto="matAutocomplete" [displayWith]="displayFn">
<mat-option *ngFor="let user of filteredUsers | async" [value]="selectedUsers">
<div (click)="optionClicked($event, user)">
<mat-checkbox [checked]="user.selected" (change)="toggleSelection(user)" (click)="$event.stopPropagation()">
{{ user.firstname }} {{ user.lastname }}
</mat-checkbox>
</div>
</mat-option>
</mat-autocomplete>
<br><br>
<label>Selected Users:</label>
<mat-list dense>
<mat-list-item *ngIf="selectedUsers?.length === 0">(None)</mat-list-item>
<mat-list-item *ngFor="let user of selectedUsers">
{{ user.firstname }} {{ user.lastname }}
</mat-list-item>
</mat-list>
TS：
import { Component, OnInit, ViewChild } from '@angular/core';
import { FormControl } from '@angular/forms';
import { Observable } from 'rxjs';
import { map, startWith } from 'rxjs/operators';
export class User {
constructor(public firstname: string, public lastname: string, public selected?: boolean) {
if (selected === undefined) selected = false;
}
}
/**
* @title Multi-select autocomplete
*/
@Component({
selector: 'multiselect-autocomplete-example',
templateUrl: 'multiselect-autocomplete-example.html',
styleUrls: ['multiselect-autocomplete-example.css']
})
export class MultiselectAutocompleteExample implements OnInit {
userControl = new FormControl();
users = [
new User('Misha', 'Arnold'),
new User('Felix', 'Godines'),
new User('Odessa', 'Thorton'),
new User('Julianne', 'Gills'),
new User('Virgil', 'Hommel'),
new User('Justa', 'Betts'),
new User('Keely', 'Millington'),
new User('Blanca', 'Winzer'),
new User('Alejandrina', 'Pallas'),
new User('Rosy', 'Tippins'),
new User('Winona', 'Kerrick'),
new User('Reynaldo', 'Orchard'),
new User('Shawn', 'Counce'),
new User('Shemeka', 'Wittner'),
new User('Sheila', 'Sak'),
new User('Zola', 'Rodas'),
new User('Dena', 'Heilman'),
new User('Concepcion', 'Pickrell'),
new User('Marylynn', 'Berthiaume'),
new User('Howard', 'Lipton'),
new User('Maxine', 'Amon'),
new User('Iliana', 'Steck'),
new User('Laverna', 'Cessna'),
new User('Brittany', 'Rosch'),
new User('Esteban', 'Ohlinger'),
new User('Myron', 'Cotner'),
new User('Geri', 'Donner'),
new User('Minna', 'Ryckman'),
new User('Yi', 'Grieco'),
new User('Lloyd', 'Sneed'),
new User('Marquis', 'Willmon'),
new User('Lupita', 'Mattern'),
new User('Fernande', 'Shirk'),
new User('Eloise', 'Mccaffrey'),
new User('Abram', 'Hatter'),
new User('Karisa', 'Milera'),
new User('Bailey', 'Eno'),
new User('Juliane', 'Sinclair'),
new User('Giselle', 'Labuda'),
new User('Chelsie', 'Hy'),
new User('Catina', 'Wohlers'),
new User('Edris', 'Liberto'),
new User('Harry', 'Dossett'),
new User('Yasmin', 'Bohl'),
new User('Cheyenne', 'Ostlund'),
new User('Joannie', 'Greenley'),
new User('Sherril', 'Colin'),
new User('Mariann', 'Frasca'),
new User('Sena', 'Henningsen'),
new User('Cami', 'Ringo')
];
selectedUsers: User[] = new Array<User>();
filteredUsers: Observable<User[]>;
lastFilter: string = '';
ngOnInit() {
this.filteredUsers = this.userControl.valueChanges.pipe(
startWith<string | User[]>(''),
map(value => typeof value === 'string' ? value : this.lastFilter),
map(filter => this.filter(filter))
);
}
filter(filter: string): User[] {
this.lastFilter = filter;
if (filter) {
return this.users.filter(option => {
return option.firstname.toLowerCase().indexOf(filter.toLowerCase()) >= 0
|| option.lastname.toLowerCase().indexOf(filter.toLowerCase()) >= 0;
})
} else {
return this.users.slice();
}
}
displayFn(value: User[] | string): string | undefined {
let displayValue: string;
if (Array.isArray(value)) {
value.forEach((user, index) => {
if (index === 0) {
displayValue = user.firstname + ' ' + user.lastname;
} else {
displayValue += ', ' + user.firstname + ' ' + user.lastname;
}
});
} else {
displayValue = value;
}
return displayValue;
}
optionClicked(event: Event, user: User) {
event.stopPropagation();
this.toggleSelection(user);
}
toggleSelection(user: User) {
user.selected = !user.selected;
if (user.selected) {
this.selectedUsers.push(user);
} else {
const i = this.selectedUsers.findIndex(value => value.firstname === user.firstname && value.lastname === user.lastname);
this.selectedUsers.splice(i, 1);
}
this.userControl.setValue(this.selectedUsers);
}
}