转到Angular 2中按钮单击的页面顶部

Question

想要点击按钮点击页面顶部,目前我使用以下代码无效:

HTML:

<button md-raised-button class="md-raised md-primary" (click)="onEdit()">Edit</button>

功能:

onEdit(){
    window.scrollTo(0,0);
  }

Answer 1

onEdit(){
    document.body.scrollTop = document.documentElement.scrollTop = 0;
  }

Answer 2

这是我的解决方案，部分基于w3schools的后退按钮示例。

的HTML：

<button (click)="topFunction()" id="myBtn" title="Go to top">Top</button>

CSS：

/*-----------------------------Button-------------------*/

#myBtn {
    display: none; /* Hidden by default */
    position: fixed; /* Fixed/sticky position */
    bottom: 20px; /* Place the button at the bottom of the page */
    right: 30px; /* Place the button 30px from the right */
    z-index: 99; /* Make sure it does not overlap */
    border: none; /* Remove borders */
    outline: none; /* Remove outline */
    background-color: red; /* Set a background color */
    color: white; /* Text color */
    cursor: pointer; /* Add a mouse pointer on hover */
    padding: 15px; /* Some padding */
    border-radius: 10px; /* Rounded corners */
    font-size: 18px; /* Increase font size */
}

#myBtn:hover {
    background-color: #555; /* Add a dark-grey background on hover */
} 

打字稿：

  @HostListener("window:scroll", []) onWindowScroll() {
    this.scrollFunction();
  }
  // When the user scrolls down 20px from the top of the document, show the button
scrollFunction() {
    if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
        document.getElementById("myBtn").style.display = "block";
    } else {
        document.getElementById("myBtn").style.display = "none";
    }
}

// When the user clicks on the button, scroll to the top of the document
topFunction() {
    document.body.scrollTop = 0; // For Safari
    document.documentElement.scrollTop = 0; // For Chrome, Firefox, IE and Opera
} 

希望它能帮助任何人

Answer 3

正确的方法是使用DOCUMENT DI 代币

导入它

import { Component, Inject } from '@angular/core';
import { DOCUMENT } from '@angular/common';

注入文档

constructor(@Inject(DOCUMENT) private dom: Document) {
}

然后你可以打电话

this.dom.body.scrollTop =0;
this.dom.documentElement.scrollTop=0;

这也适用于 SSR（Angular Universal）