我在Angular 2中无法实现平滑滚动服务。是否有任何平滑滚动或纯锚点滚动的服务可用,可以在Angular 2团队使$anchorScroll Angular2等效工作之前使用?
目前我只尝试过:将*ngFor循环增量ID设置在父div上。
[attr.id]="'point' + i"
通过传递的ID,在按钮上调用scrollto。<button
type="button"
class="btn btn-lg btn-default "
(click)="smoothScroll('point'+i)">
Scroll to point
</button>
在相关组件中,我正试图实现一个普通的JavaScript平滑滚动函数。
smoothScroll(eID) {
var startY = currentYPosition();
var stopY = elmYPosition(eID);
var distance = stopY > startY ? stopY - startY : startY - stopY;
if (distance < 100) {
scrollTo(0, stopY); return;
}
var speed = Math.round(distance / 100);
if (speed >= 20) speed = 20;
var step = Math.round(distance / 25);
var leapY = stopY > startY ? startY + step : startY - step;
var timer = 0;
if (stopY > startY) {
for (var i = startY; i < stopY; i += step) {
setTimeout(this.win.scrollTo(0, leapY), timer * speed);
leapY += step; if (leapY > stopY) leapY = stopY; timer++;
} return;
}
for (var i = startY; i > stopY; i -= step) {
setTimeout(this.win.scrollTo(0,leapY), timer * speed);
leapY -= step; if (leapY < stopY) leapY = stopY; timer++;
}
}
function currentYPosition() {
// Firefox, Chrome, Opera, Safari
if (self.pageYOffset) return self.pageYOffset;
// Internet Explorer 6 - standards mode
if (document.documentElement && document.documentElement.scrollTop)
return document.documentElement.scrollTop;
// Internet Explorer 6, 7 and 8
if (document.body.scrollTop) return document.body.scrollTop;
return 0;
}
function elmYPosition(eID) {
var elm = document.getElementById(eID);
var y = elm.offsetTop;
var node = elm;
while (node.offsetParent && node.offsetParent != document.body) {
node = node.offsetParent;
y += node.offsetTop;
} return y;
}
我还在尝试为来自窗口提供程序的this._win.scrollTo提供访问权限。
import {Injectable, Provider} from 'angular2/core';
import {window} from 'angular2/src/facade/browser';
import {unimplemented} from 'angular2/src/facade/exceptions';
function _window(): Window {
return window
}
export abstract class WINDOW {
get nativeWindow(): Window {
return unimplemented();
}
}
class WindowRef_ extends WINDOW {
constructor() {
super();
}
get nativeWindow(): Window {
return _window();
}
}
export const WINDOW_PROVIDERS = [
new Provider(WINDOW, { useClass: WindowRef_ }),
];
**编辑** ---------------------
我将this.win.scrollTo更改为this.win.window.scrollTo,现在我得到了类似于angular1.x $anchorscroll的效果,其中滚动是快速而不是流畅的过渡,但是滚动不够平滑,我收到以下异常错误。
更新
在发现angular2的setTimeout稍有不同后,我不再收到该错误,但是滚动仍然是瞬间的,而不是平滑的。
我改变了
setTimeout(this.win.scrollTo(0, leapY), timer * speed);
到
setTimeout(() => this.win.scrollTo(0, leapY), timer * speed);