Angular自定义组件实现ngModel双向绑定

1.自定义组件ts

@Component({
  selector: 'app-custom-tree',
  templateUrl: './custom-tree.component.html',
  styles: [],
  providers: [{
    provide: NG_VALUE_ACCESSOR,
    useExisting: forwardRef(() => CustomTreeComponent),
    multi: true
  }]
})
export class CustomTreeComponent implements OnInit, ControlValueAccessor {
  dataTrees: NzTreeNodeOptions[] = [];
  @Output() selectTreechange = new EventEmitter();
  onChangeListener; // 改变值回调
  onTouchedListener; // 交互回调
  isDisabled: boolean;
  _checkNode: string[];
  checkKeys: string[];
  constructor(private service: customService) { }

  //#region  值双向绑定
  writeValue(obj: any): void {
    this.checkKeys = obj;//obj就是由调用此组件处的ngModel传入的值
  }
  registerOnChange(fn: any): void {
    this.onChangeListener = fn; // 保存这个函数
  }
  registerOnTouched(fn: any): void {
    this.onTouchedListener = fn; // 保存这个函数
  }
  setDisabledState?(isDisabled: