防止在角度剑道多选中删除退格中的选定项目

如何解决防止在角度剑道多选中删除退格中的选定项目

我有一个剑道多选控件。默认情况下，退格键删除最后选择的项目。因此，我尝试在this kendo doc

之后的键为“ Enter key”时限制用户输入

 <kendo-multiselect #multiselect [data]="groupsDataSource"
                     placeholder="Type Group Id or Group Name"
                     [filterable]="true"
                     [textField]="'displayName'"
                     [valueField]="'id'"
                     [autoClose]="false"
                     (filterChange)="handleFilter($event)"
                     [virtual]="virtual">
  </kendo-multiselect>

  @ViewChild('multiselect',{ static: false }) public multiselect: MultiSelectComponent;
  @ViewChild('multiselect',{ static: false }) public userInput: ElementRef;

  ngAfterViewInit() {
    this.bindKeyChange();
  }

bindKeyChange() {

 let searchbar = document.getElementsByClassName("k-searchbar")[0];
let input = searchbar.getElementsByClassName("k-input")[0];
input.addEventListener('keyup',function (event) {
  console.log("within input");
  if (event.keyCode == 8) {
    event.stopImmediatePropagation();
    event.preventDefault();
  }
});

//let event = new KeyboardEvent('keyup',{ 'bubbles': true });
//this.userInput.nativeElement.dispatchEvent(event);

//this.multiselect.wrapper.nativeElement.dispatchEvent(event);
//this.multiselect.hostElement.children[0].onkeydown(function (e) { // host element is a private property
  //console.log('key down');
 //})
}

onKeyup(event) {
   console.log(event)
}

onKeydown(event) {
  console.log(event)
}

这无法将keyup / keydown事件与控件绑定。 我们如何实现这一目标？