硒:滚动到页面末尾 [英] Selenium: Scroll till end of the page

问题描述

硒:

我是 WebDriverJS 的新手.我已经在Java中尝试过这种方法.

I am new to WebDriverJS. I have tried this approach in Java.

Long repaeted = 0l, scrollHeight = 0l, returnHeight = 0l;
while(true){
    if (repaeted == 0) {
        returnHeight = (Long) jse.executeScript("var scroll =document.documentElement.scrollHeight;window.scrollTo(0, scroll); return scroll;");
         System.out.println("Height : "+scrollHeight +"\t Chnage : "+returnHeight+ "\t Repeated : "+repaeted);
         scrollHeight = returnHeight;
     }else {
         returnHeight = (Long) jse.executeScript("var scroll =  document.documentElement.scrollHeight;window.scrollTo(0, scroll); return scroll;");
         System.out.println("Height : "+scrollHeight +"\t Chnage : "+returnHeight+ "\t Repeated : "+repaeted);
         if (scrollHeight.intValue() == returnHeight.intValue()) {
             System.out.println("Break.."+ returnHeight);
             break;
         } else { scrollHeight = returnHeight; }
     }
            repaeted++;
 } 

但是我在循环时遇到了webdriverjs中的问题.

var webdriver = require('..'),
    By = webdriver.By,
    until = webdriver.until;
// make sure chromedriver can be found on your system PATH
var driver = new webdriver.Builder()
    .forBrowser('chrome')
    .withCapabilities(webdriver.Capabilities.chrome())
    .build();


driver.get('https://in.yahoo.com/').then(function(){
        var window = new webdriver.WebDriver.Window(driver);
        window.maximize();
        driver.manage().timeouts().implicitlyWait(1000 * 3);
    })
    .then(function(){
        console.log('Entered');
        var check = 0, count = 0
        for(var i = 0; i< 50; i++){
        //driver.sleep(1000 * 2);
driver.executeScript('var dynamicscroll = document.documentElement.scrollHeight;window.scrollTo(0, dynamicscroll);return dynamicscroll;').then(function(height){
        console.log('Check : '+check+'  Height : '+height +'  Repeated : '+(count++));
        if(check === 0 || check !== height){console.log('continue'); check = height; }
        else { console.log('break'); i = 100; }
            });
        }
        })
    .then(null, function(err) {
      console.error("An error was thrown! By Promise..." + err);
    });

driver.quit();

在我的代码中我已经为循环硬编码了50次，直到滚动高度结束时我想退出/中断循环.在这种方法中，我想删除像Java代码这样的硬代码，因为我不知道要为滚动不断增长的其他应用程序迭代多少次. 例如，Facebook应用程序，Yahoo新闻...

In my code I have hardcoded for loop to iterate until 50 times and I want to quit/break the loop when the scroll height is reached to end. In this approach, I want to remove hardcode like java-code because I don't know how many times to iterate for other applications whose scroll is kept on increasing dynamically. For example, Facebook application, Yahoo News...

推荐答案

根据页面的实现方式，滚动到动态页面的底部可能具有挑战性.

Scrolling to the bottom of a dynamic page can be challenging depending on how it is implemented by the page.

首先，您必须使用滚动条找到该容器，因为它可能不同于链接到window.scrollTo的容器.

First you'll have to find the container with the scrollbar since it can be different from the one linked to window.scrollTo.

然后通过增加scrollTop滚动容器，直到scrollHeight稳定且没有待处理的请求.要检查是否有待处理的请求，请评估页面上是否具有JQuery的jQuery.active，或挂接XMLHttpRequest来监视send上的调用.

Then scroll the container by increasing scrollTop until the scrollHeight becomes steady with no pending requests. To check if there are pending requests, either evalute jQuery.active if the page has JQuery or hook XMLHttpRequest to monitor the calls on send.

以下是在通用函数上使用多次滚动到页面底部或直到末尾的示例:

Here is an example using on a generic function to scroll to the bottom of the page a number of times or until the end:

var webdriver = require('selenium-webdriver');

var driver = new webdriver.Builder().forBrowser('chrome').build();

driver.get('https://groups.google.com/forum/#!search/webdriverjs');

 // scroll to the bottom 3 times
driver.executeAsyncScript(scrollBottom, 3)
  .then(n => console.log(`scrolled ${n} time(s)`));

 // scroll to the bottom until the end
driver.executeAsyncScript(scrollBottom)
  .then(n => console.log(`scrolled ${n} time(s)`));

function scrollBottom(){
  var count = arguments[arguments.length - 2] || 0x7fffffff;
  var callback = arguments[arguments.length - 1];

  /* get the scrollable container */
  var elm = document.elementFromPoint(window.innerWidth - 25, window.innerHeight / 2);
  for ( ;elm && (++elm.scrollTop, !elm.scrollTop); elm=elm.parentElement);
  elm = elm || document.documentElement;

  /* hook XMLHttpRequest to monitor Ajax requests */
  if (!('idle' in XMLHttpRequest)) (function(){
    var n = 0, t = Date.now(), send = XMLHttpRequest.prototype.send;
    var dispose = function(){ --n; t = Date.now(); };
    var loadend = function(){ setTimeout(dispose, 1) };
    XMLHttpRequest.idle = function() { return n > 0 ? 0 : Date.now() - t; };
    XMLHttpRequest.prototype.send = function(){
      ++n;
      this.addEventListener('loadend', loadend);
      send.apply(this, arguments);
    };
  })();

  /* scroll until steady scrollHeight or count of scroll and no pending request */
  var i = 0, scrollHeight = -1, scrollTop = -1;
  (function scroll(){
    if ((scrollHeight === elm.scrollHeight || i === count) && XMLHttpRequest.idle() > 60)
      return callback(i);
    scrollTop = elm.scrollTop;
    scrollHeight = elm.scrollHeight;
    if (i < count)
      i += (elm.scrollTop = 0x7fffffff, scrollTop !== elm.scrollTop);
    setTimeout(scroll, 100);
  })();
}

或滚动直到在特定时间(此处为5秒)内不再增加高度:

Or by scrolling until the height no longer increases during a specific time (5 seconds here) :

function scrollBottom(){
  var count = arguments[arguments.length - 2] || 0x7fffffff;
  var callback = arguments[arguments.length - 1];
  var timeout = 5000;  /* 5 seconds timeout */
  var i = 0;

  /* get the scrollable container */
  var elm = document.elementFromPoint(window.innerWidth - 25, window.innerHeight / 2);
  for ( ;elm && (++elm.scrollTop, !elm.scrollTop); elm=elm.parentElement);
  elm = elm || document.documentElement;

  /* scroll while the height is increasing or until timeout */
  (function scroll(){
    var endtime = Date.now() + timeout;
    var height = elm.scrollHeight;
    elm.scrollTop = 0x7fffffff;  /* scroll */

    setTimeout(function check(){
      if (Date.now() > endtime)            /* returns if waited more than 5 sec */
        callback(i);
      else if (elm.scrollHeight == height) /* wait again if same height  */
        setTimeout(check, 60);
      else if (++i === count)              /* returns if scrolled the expected count */
        callback(i);
      else                                 /* scroll again */
        setTimeout(scroll, 60);
    }, 250);
  })();
}

这篇关于硒:滚动到页面末尾的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！