我的 Angular 项目中有一个 mat-select,它从服务器获取值并显示它们。我需要做的是确保在收到的值恰好是 1 的情况下,将其显示为默认值,但仅在这种情况下,因为这些值不是预先确定的。有没有办法做到这一点?
HTML:
<div class="combo">
<div>
<mat-form-field appearance="outline" class="calendarfilter">
<mat-label>Utente</mat-label>
<mat-select (selectionChange)="filteredUsers.emit($event.value)" [value]="null">
<mat-option *ngFor="let user of users" [value]="user.id">
{{user.descrizione}}
</mat-option>
</mat-select>
</mat-form-field>
</div>
</div>
TS:
import { Component, EventEmitter, Input, OnInit, Output } from '@angular/core';
import { UtentiAgenda } from 'src/app/models/EventoServer';
@Component({
selector: 'app-user-filter',
templateUrl: './user-filter.component.html',
styleUrls: ['./user-filter.component.css']
})
export class UserFilterComponent implements OnInit {
@Input() users: UtentiAgenda[]
@Output() filteredUsers: EventEmitter<number>= new EventEmitter()
constructor() { }
ngOnInit(): void {
}
}
主页组件中的 HTML:
<app-user-filter class="filterbar" *ngIf="release=='wincar' && userAgenda != null" [users]="userAgenda" (filteredUsers)="userChanged($event)">
</app-user-filter>