无法在角度材质选择上使用renderer2禁用setAttribute

我无法使用renderer2禁用角度材质的选择下拉菜单。下面是我的代码

Component.html

            <mat-select #exLoc (selectionChange)="someFun($event)" [(value)]="someVal">
              <mat-option aria-selected="true" [value]="locVal" *ngFor="let location of locations">{{location.LocationName}}
              </mat-option>
            </mat-select>

Component.ts

constructor(public renderer: Renderer2) {} 
@ViewChild('exLoc') exLoc: ElementRef;
functionToDisableDropDown() {
 this.renderer.setAttribute(this.exLoc, 'disabled', 'true');
}