bug(cdk-virtual-scroll-viewport): If there is not enough data without caching, the scrolling operation will be invalid.

[soulxy]

Is this a regression?

No response

Description

If there is not enough data without caching, the scrolling operation will be invalid.

Reproduction

StackBlitz link:https://stackblitz.com/edit/angular-sbfsdw?file=src%2Fapp%2Fapp.component.ts,src%2Fapp%2Fng-zorro-antd.module.ts,src%2Fapp%2Fapp.module.ts
Steps to reproduce:

1. If you scroll the mouse in the container, the scroll bar will always react, resulting in unsuccessful scrolling.
2. If you drag the scroll bar directly, you can basically scroll normally, and if the data length is in a certain interval, there will be obvious problems of unsuccessful scrolling.

The core code is as follows：

@Component({
  selector: 'nz-demo-button-basic',
  template: `
   <cdk-virtual-scroll-viewport itemSize="250" class="example-viewport">
  <div *cdkVirtualFor="let item of items; templateCacheSize: 0" class="example-item">
  <app-my [name]="name"></app-my>
  <!-- <div class="analysis-middle-indicators-charts" style="height: 250px;">
         <app-my [name]="name"></app-my>
      </div> -->
  </div>
</cdk-virtual-scroll-viewport>
  `,
  styles: [
    `
   .example-viewport {
  height: 600px;
  width: 200px;
  border: 1px solid black;
}

.example-item {
  height: 250px;
  border: 1px solid red;
}
    `,
  ],
  changeDetection: ChangeDetectionStrategy.OnPush,
})
export class NzDemoButtonBasicComponent {
  // length 20000 scroll working
  // length 20 scroll no working
  items = Array.from({ length: 20 }).map((_, i) => `Item #${i}`);
}

Expected Behavior

No matter the size of itemsize or the amount of data, the scrolling effect is normal.

Actual Behavior

Unable to scroll up and down

Environment

• Angular: 16+、18+
• CDK/Material: 16+、18+
• Browser(s):
• Operating System (e.g. Windows, macOS, Ubuntu):