Angular 路由器中的 Scrollspy 效果

Question

我正在尝试将 Scrollspy 效果添加到 Angular 项目中。当用户单击 link，而不是将其显示为新页面时，该组件应向上滚动，下一个组件应到达该位置。有没有办法在 Angular 中使用路由来做到这一点？当 link 被点击时，页面应该像下面的 jquery 代码一样滚动到顶部

$('html, body').animate({scrollTop: offsetTop}, 'normal');

Angular 中是否有任何库或功能？

Answer 1

我一直在寻找处理滚动的非常简单的方法，最后我制定了自己的指令：

@Directive({
  selector: '[scrollSpy]'
})
export class ScrollSpyDirective {
  @Input() public spiedTags = [];
  @Output() public sectionChange = new EventEmitter<string>();
  private currentSection: string;

  constructor(private _el: ElementRef) {}

  @HostListener('scroll', ['$event'])
  onScroll(event: any) {
    let currentSection: string;
    const children = this._el.nativeElement.children;
    const scrollTop = event.target.scrollTop;
    const parentOffset = event.target.offsetTop;
    for (let i = 0; i < children.length; i++) {
      const element = children[i];
      if (this.spiedTags.some(spiedTag => spiedTag === element.tagName)) {
        if (element.offsetTop - parentOffset <= scrollTop) {
          currentSection = element.id;
        }
      }
    }
    if (currentSection !== this.currentSection) {
      this.currentSection = currentSection;
      this.sectionChange.emit(this.currentSection);
    }
  }
}

Here is a demo link with routing integrated. For some reason, the stackblitz edition version 中断了 stackblitz 编辑器的滚动。

Answer 2

这是 Angular 9 的工作版本：

import { Directive, Input, EventEmitter, Output, ElementRef, HostListener } from '@angular/core';

@Directive({
    selector: '[scrollSpy]'
})

export class ScrollSpyDirective {
    @Input() public spiedTags = [];
    @Output() public sectionChange = new EventEmitter<string>();
    private currentSection: string;

    constructor(private _el: ElementRef) {}

    @HostListener('window:scroll', ['$event'])
    onScroll(event: any) {
        let currentSection: string;
        const children = this._el.nativeElement.children;
        const scrollTop = event.target.scrollingElement.scrollTop;
        const parentOffset = event.target.scrollingElement.offsetTop;
        for (let i = 0; i < children.length; i++) {
            const element = children[i];
            if (this.spiedTags.some(spiedTag => spiedTag === element.tagName)) {
                if ((element.offsetTop - parentOffset) <= scrollTop) {
                    currentSection = element.id;
                }
            }
        }

        if (currentSection !== this.currentSection) {
            this.currentSection = currentSection;
            this.sectionChange.emit(this.currentSection);
        }
    }
}

Angular 路由器中的 Scrollspy 效果

Scrollspy effect in Angular router

scroll

angular-routing

angular