@HostListener('dragstart', ['$event'])

onDragStart(ev: Event) {

    console.log('this.el.nativeElement', this.el.nativeElement); //打印值：<mat-list-item>

    console.log('ev.target', ev.target); //打印值：<div class="mat-list-item-content">

    if (this.el.nativeElement === ev.target) {

        this.rd.addClass(this.el.nativeElement, this.draggedClass);

        console.log('added class');

    }

}

@HostListener('dragend', ['$event'])

onDragEnd(ev: Event) {

    if (this.el.nativeElement === ev.target) {

        this.rd.removeClass(this.el.nativeElement, this.draggedClass);

    }

}

GitHub: https://github.com/LeMueller/angular_task_manager

这样导致
this.el.nativeElement === ev.target
总是false