此代码的目的是检索搜索结果的URL。除非您滚动整个页面,否则我正在使用的网站不会加载所有结果。但是,滚动加载所有结果后需要花费几秒钟的时间,并且按原样执行下一行,并且仅检索前几个链接而不是整个页面。
我想我需要做的只是停留几秒钟。
此示例中的xpath用于google,它不会延迟加载,我正在使用的网站位于登录名后面,并且确实会延迟加载。
window.scrollTo({ top:document.body.scrollHeight, behavior: 'smooth', })
///pause here
try {
var maxLinks = 25;
var returnData = "URL";
var xPath = '//*[@class="r"]/a';
var xpathResults = document.evaluate(xPath, document, null, 0, null);
var oNode = xpathResults.iterateNext();
var nodeList = [];
var linkCount = 0;
var hrefStr;
var returnStr;
var linkText;
while (oNode && (linkCount < maxLinks)) {
if (oNode.href !== hrefStr) {
linkCount += 1;
hrefStr = oNode.href;
linkText = oNode.textContent;
if (returnData === "MD") {
returnStr = "[" + linkText + "](" + hrefStr + ")";
}
else {
returnStr = hrefStr;
}
nodeList.push(returnStr);
}
oNode = xpathResults.iterateNext();
}
returnResults = nodeList.join('\n');
} catch (pError) {
if (!oError.message) {
oError.message = pError.toString();
}
oError.message = "[ERROR]"
+ "\n\nError Number: " + oError.errorNumber + "\n"
+ oError.message
returnResults = oError.message;
}
function copyToClipboard(text) {
var dummy = document.createElement("textarea");
document.body.appendChild(dummy);
dummy.value = text;
dummy.select();
document.execCommand("copy");
document.body.removeChild(dummy);
}
copyToClipboard(returnResults)
copyToClipboard(returnResults)
有sleep方法解决方案,允许您在操作之间等待时间,如我之前在评论中所提到的。
这是我的解决方法:
function sleep (time) { //Sleep function
return new Promise((resolve) => setTimeout(resolve, time));
}
sleep(500).then(() => { //Wait the stated time then do something..
var maxLinks = 25;
var returnData = "URL";
var xPath = '//*[@class="r"]/a';
var xpathResults = document.evaluate(xPath, document, null, 0, null);
var oNode = xpathResults.iterateNext();
var nodeList = [];
var linkCount = 0;
var hrefStr;
var returnStr;
var linkText;
while (oNode && (linkCount < maxLinks)) {
if (oNode.href !== hrefStr) {
linkCount += 1;
hrefStr = oNode.href;
linkText = oNode.textContent;
if (returnData === "MD") {
returnStr = "[" + linkText + "](" + hrefStr + ")";
}
else {
returnStr = hrefStr;
}
nodeList.push(returnStr);
}
oNode = xpathResults.iterateNext();
}
returnResults = nodeList.join('\n');
} catch (pError) {
if (!oError.message) {
oError.message = pError.toString();
}
oError.message = "[ERROR]"
+ "\n\nError Number: " + oError.errorNumber + "\n"
+ oError.message
returnResults = oError.message;
}
function copyToClipboard(text) {
var dummy = document.createElement("textarea");
document.body.appendChild(dummy);
dummy.value = text;
dummy.select();
document.execCommand("copy");
document.body.removeChild(dummy);
}
copyToClipboard(returnResults)
copyToClipboard(returnResults)
});
}
没有与Java中相同的sleep()。如果您不明白为什么,则需要阅读有关JavaScript中的线程处理(或缺少线程处理)的信息。但是,您可以创建一个异步函数,然后使用await调用它(但是您的代码将需要在异步函数中:
function sleep(millis) {
return new Promise(resolve => setTimeout(resolve, millis));
}
async function doIt() {
const max = 4;
let count = 0;
while (count < max) {
await sleep(1000);
console.log('loop: %s', count);
count++;
}
}
doIt();