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我正在尝试以角度使用 cdkDragDropModule 创建表布局，我从数据库中获取表对象并将表对象预加载到拖放容器中的正确位置。一切正常，但我收到以下错误：

ServerOrderComponent.html:13 ERROR Error: ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked. Previous value: 'freeDragPosition: [object Object]'. Current value: 'freeDragPosition: undefined'.
at viewDebugError (core.js:23059)
at expressionChangedAfterItHasBeenCheckedError (core.js:23047)
at checkBindingNoChanges (core.js:23257)
at checkNoChangesNodeInline (core.js:31601)
at checkNoChangesNode (core.js:31586)
at debugCheckNoChangesNode (core.js:32183)
at debugCheckDirectivesFn (core.js:32115)
at Object.eval [as updateDirectives] (ServerOrderComponent.html:13)
at Object.debugUpdateDirectives [as updateDirectives] (core.js:32108)
at checkNoChangesView (core.js:31485)

我的 component.html 是

 <div class="example-boundary">
<div class="example-box"
     cdkDragBoundary=".example-boundary"
     cdkDrag
     [cdkDragStartDelay]="2000"
     *ngFor="let table of tables"
     id="{{table._id}}"
     (cdkDragEnded)="dragEnd($event, table)"
     (click)="orderScreen(table)"
     [cdkDragFreeDragPosition]="getTablePosition(table)">{{table.username}}
</div>

并且 component.ts 是

tables: User[] = [];
  loading = true;
  dragPosition: any;
  tableMoved = false;
  firstEntry = true;
  initializedTables: string[] = [];

  constructor(private router: Router, private userService: UserService, private alertService: AlertService, private cartService: CartService, private cdr: ChangeDetectorRef) {
  }

  ngAfterViewInit() {
    this.getAllTables();
    this.cartService.removeAllFromCart();
  }

 
  getTablePosition(table: User) {
    if(!this.initializedTables.includes(table.uuid)) {
      this.initializedTables.push(table.uuid);
      return {x: table.posX, y: table.posX};
    }
  }

  dragEnd($event: CdkDragEnd, table: User) {
    const { x, y } = $event.distance;
    table.posX =  x;
    table.posY =  y;
    this.tableService.update(table).subscribe(() => {
    },
      error => {
        this.alertService.error(error);
        this.loading = false;
      });
  }


  orderScreen(table: User) {
    if (this.tableMoved) {
      this.tableMoved = false;
    } else {
      return 
    }
  }

我已经尝试了一切，但似乎无法让它消失。

4

2 回答 2

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尝试在函数 getAllTables 中使用超时，如下例所示： ngAfterViewInit() { setTimeout(() => { this.paginator.page .pipe( startWith(null), tap(() => this.dataSource.loadLessons(...)) ).subscribe(); }); }

于 2021-02-08T02:21:42.257 回答
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找出原因，原因是我在下面的代码中传递了一个方法。一旦我更改为变量，它就被修复了

[cdkDragFreeDragPosition]="getTablePosition(table)"
于 2021-02-08T02:29:38.783 回答