如何在angular中默认选择mat-list中的第一项

import { MatListModule } from '@angular/material/list';

@NgModule({
  imports: [
    // ...
    MatListModule,
  ],
  // ...
})
export class YourModule {}

<mat-list>
  <mat-list-item *ngFor="let item of items; let i = index" [class.selected]="i === selectedIndex">
    {{item}}
  </mat-list-item>
</mat-list>

export class YourComponent {
  items = ['Item 1', 'Item 2', 'Item 3'];
  selectedIndex = 0; // 默认选中第一项
}

.mat-list-item.selected {
  background-color: #f5f5f5; /* 选中时的背景色 */
}

selectItem(index: number) {
  this.selectedIndex = index;
}

<mat-list-item *ngFor="let item of items; let i = index" [class.selected]="i === selectedIndex" (click)="selectItem(i)">
  {{item}}
</mat-list-item>