import { Component, ViewChild, AfterViewInit } from '@angular/core';
@Component({
? selector: 'my-app',
? template: `
? ? <h1>Welcome to Angular World</h1>
? ? <p #greet>Hello {{ name }}</p>
? `,
})
export class AppComponent {
? name: string = 'Semlinker';
? @ViewChild('greet')
? greetDiv: ElementRef;
? ngAfterViewInit() {
? ? console.log(this.greetDiv.nativeElement);
? }
}

<div *ngIf="isButtnGrop" (click)="dropBtnClick($event)">
  <div cdkDropList #dropList [cdkDropListConnectedTo]="_connectableDropLists" (cdkDropListDropped)="drop($event)">
    <div *ngFor="let item of itemDatas" (click)="onItemClick($event,item)" cdkDrag
      (cdkDragStarted)="startDragging($event)" [cdkDragData]="{ item }">
    </div>
  </div>
</div>

@ViewChild('dropList', { read: CdkDropList, static: false }) dropList: CdkDropList;
ngAfterViewInit(): void {
? ? if (this.dropList) {
? ? ? console.log(this.dropList)
? ? }
? }

import { CdkDragDrop, CdkDropList, moveItemInArray } from '@angular/cdk/drag-drop';

const parentId = this.storeService.getProperty(this.pageId, this.componentId, 'parentId');
this.dragDropService.getDragListsAsync(this.pageId, parentId.value)
? ? ? .pipe(takeUntil(this.destroy))
? ? ? .subscribe(dropLists => {
? ? ? ? this._connectableDropLists = dropLists || [];
? ? ? });
this.storeService.getPropertyAsync(this.pageId, this.componentId, 'children')
? ? ? .pipe(takeUntil(this.destroy)).subscribe(result => {
? ? ? ? if (!result || result.length === 0) {
? ? ? ? ? this._children = [];
? ? ? ? ? this._dragData = [];
? ? ? ? ? this.changeRef.markForCheck();
? ? ? ? } else {
? ? ? ? ? const dropbuttonArray = result.filter((item) => {
? ? ? ? ? ? const itemType = this.storeService.getProperty(this.pageId, item, 'componentType');
? ? ? ? ? ? if (itemType === AdmComponentType.DropdownButton) return item;
? ? ? ? ? });
? ? ? ? ? if (dropbuttonArray.length > 0) {
? ? ? ? ? ? this._connectableDropLists = [];
? ? ? ? ? ? dropbuttonArray.forEach(comId => {
? ? ? ? ? ? ? this.dragDropService.getDragListsAsync(this.pageId, comId)
? ? ? ? ? ? ? ? .pipe(takeUntil(this.destroy))
? ? ? ? ? ? ? ? .subscribe(dropLists => {
? ? ? ? ? ? ? ? ? this._connectableDropLists.push(...dropLists);
? ? ? ? ? ? ? ? });
? ? ? ? ? ? });
? ? ? ? ? }
? ? ? ? }
? ? ? });

drop(event: CdkDragDrop<any>) {
? ? if (event.previousContainer != event.container) {
? ? ? const { eventData } = event.item.data;
? ? ? const componentId = eventData[event.previousIndex];
? ? ? const oldParentId = this.storeService.getProperty(this.pageId, componentId, 'parentId', false)?.value;
? ? ? // delete oldParent children
? ? ? const oldParent = this.storeService.getProperties(this.pageId, oldParentId);
? ? ? const index = oldParent.children.indexOf(componentId);
? ? ? oldParent.children.splice(index, 1);
? ? ? // add newParent children
? ? ? const oldChildren = this.itemDatas.map(x => x.id.value);
? ? ? oldChildren.splice(event.currentIndex, 0, componentId);
? ? ? this.storeService.setProperty(this.pageId, componentId, 'parentId', { value: this.componentId }, [[this.pageId, componentId]]);
? ? ? this.storeService.setProperty(this.pageId, oldParentId, 'children', oldParent.children, [[this.pageId, oldParentId]]);
? ? ? this.storeService.setProperty(this.pageId, this.componentId, 'children', oldChildren);
? ? ? this.changeDetector.markForCheck();
? ? ? return;
? ? }
? ? moveItemInArray(this.itemDatas, event.previousIndex, event.currentIndex);
? ? const children = this.itemDatas.map(x => x.id.value);
? ? this.storeService.setProperty(this.pageId, this.componentId, 'children', children);
? }