angular - cd.markForCheck and cd.detechChanges not updating children

Question

I'm learning Angular's Change Detection and created an example with the OnPush strategy.

In the parent component I'm mutating an object and triggering the CD:

  public updateCustomerArray1() {
    this.customers1[0].firstName = "Andreas 1 - changed";
    this.cd.markForCheck();
    this.cd.detectChanges();
    this.app.tick();
  }

 <app-child1 [customers]="customers1"></app-child1>

but the change is not propagated to the child components. Why?

https://github.com/ILoveITScience/AngularChangeDetection/tree/master/ChangeDetectionOnPush/src/app

PS: I know I should not mutate objects but create new once. But I would like to understand why the CD does not work here.

Answer 1

等待大神解答