在Angular中使用虚拟滚动时，有时候会遇到显示问题。这些问题通常是出现在滚动中的元素大小不一致的情况下。在此情况下，因为使用了虚拟滚动，所以只有少量的元素会被渲染。这样的话，它们的大小会影响渲染出来的元素的数量。

为了解决这个问题，我们可以对VirtualScrollStrategy进行扩展，在该扩展中，我们可以实现自己对ElementRef和ViewContainerRef的处理方式，从而确保元素会正确的被渲染出来。以下是一个示例：

import {CollectionViewer, DataSource, ListRange} from '@angular/cdk/collections';
import { BehaviorSubject, Observable, of } from 'rxjs';
import {catchError, finalize} from 'rxjs/operators';
import { ElementRef, Injectable, OnDestroy, ViewContainerRef } from '@angular/core';
import { CdkVirtualScrollViewport, VirtualScrollStrategy } from '@angular/cdk/scrolling';

@Injectable()
export class CustomVirtualScrollStrategy implements VirtualScrollStrategy, OnDestroy {
  private indexChange = new BehaviorSubject(0);
  private dataStream = new BehaviorSubject([]);
  private pooledPages = new Map();

  private viewRef: any;

  private snappedIndex = 0;

  constructor(private elementRef: ElementRef, private viewContainer: ViewContainerRef) {
    this.elementRef.nativeElement.style.overflow = 'auto';
  }

  ngOnDestroy(): void {}

  scrolled(index: number): void {
    const snappedIndex = this.getSnappedIndex(index);
    if (this.snappedIndex !== snappedIndex) {
        this.snappedIndex = snappedIndex;
        const maxIndex = this.viewRef.getDataLength() - 1;
        const start = Math.max(0, this.snappedIndex - 20);
        const end = Math.min(this.snappedIndex + 20, maxIndex);
        const pages = new Set();
        for (let i = start; i <= end; i++) {
            const pageIndex = Math.floor(i / this.viewRef.getPageSize());
            pages.add(pageIndex);
        }
        pages.forEach(page => this.fetchPage(page));
    }
  }

  attach(viewRef: any): void {
    this.viewRef = viewRef;
    this.viewContainer.createEmbeddedView(viewRef.templateRef);
  }

  detach(): void {
    this.viewContainer.clear();
    this.viewRef = null;
  }

  onDataLengthChanged(): void {
    this.indexChange.next(this.getAdjustedIndex(this.sn