@ViewChild throws undefined due to ngIf, how to solve the problem?

Question

Angular

I have a parent component and it looks like this.

export class ParentComponent {
  @ViewChild(ChildComponent) childComponent: ChildComponent;
  public showChild: boolean = false;

  clickHandler() {
     this.showChild = true;
     this.childComponent.setSomething()
  }
}

There is a showChild variable that shows the childComponent via ngIf ChildComponent has a setSomething() method that I call in the parent component's click handler. ClickHandler() triggers an error
<child *ngIf="showChild "></child >

ERROR TypeError: Cannot read property 'setSomething' of undefined

Since ngIf has not yet worked and the component has not been rendered, even though it is preceded by this.showChild = true;

How to solve this problem?