C#爬虫之通过Selenium获取浏览器请求响应结果
前言
在进行某些爬虫任务的时候，我们经常会遇到仅用Http协议难以攻破的情况，比如协议中带有加密参数，破解需要花费大量时间，那这时候就会用Selenium去模拟浏览器进行页面上的元素抓取
大多数情况下我们用Selenium只是爬取一下页面上可见的元素信息或者做一些模拟人工的操作，但页面可见元素的数据字段毕竟有限，有许多有用的字段隐藏在接口响应中的，但是要如何拿到接口响应内容呢？
在网上搜索Selenium如何获取Chrome中Network数据包响应结果，大多数的文章都是Python或者Java，C#的资源少之又少，虽然知道原理，但每个语言之间SDK代码实现相差很大，C#的SDK真的有点魔改，需要自己慢慢摸索
探索
通过寻找资料，大致就2种方案
方案1：通过Selenium指定本地一个代理去截取所有请求，类似于常见抓包工具的原理，但是C#是没有这种插件，也有可能是我没找到，比如Python和Java有一个叫Browsermob-Proxy的插件，可以和Selenium深度结合实现代理抓包。我利用FiddlerCore做了一个本地代理工具，但是并不好用，不能和Selenium进行深度绑定使用，会导致Selenium爬取过程和请求截取是异步进行的，强行用代码实现同步又很难受，达不到我想要的要求
方案2：Selenium通过chromedriver开启浏览器的性能日志功能，记录类型为Performance的日志，该功能在Selenium中叫做 PerformanceLoggingPreferences。网页加载完成后，可以通过Selenium拿到浏览器Performance Logs摘要信息，再利用Log中的RequestId调用Chrome CDP命令去浏览器端获取日志的完整内容。Selenium封装的CDP，本质上还是Http请求，只是带着驱动窗口的SessionId和Chrome的API做交互
方案1参考资料：
https://blog.csdn.net/qq_32502511/article/details/101536325 （Python + Browsermob-Proxy）
https://blog.csdn.net/fontcolor0/article/details/103297635/ （Java + Browsermob-Proxy）
https://www.cnblogs.com/airoot/articles/14888284.html (C# + FiddlerCore)
方案2参考资料：
https://chromedevtools.github.io/devtools-protocol/ （Chrome DevTools Protocol 介绍）
https://www.jianshu.com/p/615e3c0140a5 （Python + 开启PerfLoggingPref）
https://blog.csdn.net/weixin_49855251/article/details/112281901 (不同日志类型的介绍)
https://blog.csdn.net/bigcarp/article/details/115065730 （Java + 原生CDP协议获取日志内容）
上手
启用Logging：
C#伪代码示例：
首先需要安装最新的Nuget包：OpenQA.Selenium
var option = new ChromeOptions();
option.SetLoggingPreference("performance",OpenQA.Selenium.LogLevel.Info); //启用performance日志，等级为Info即可
option.PerformanceLoggingPreferences = new ChromiumPerformanceLoggingPreferences() {
IsCollectingNetworkEvents = true //采集网络请求事件
};
using (ChromeDriver driver = new ChromeDriver(driverPath,option,TimeSpan.FromSeconds(5))) {
driver.Navigate().GoToUrl("https://item.m.jd.com/product/10052422060501.html");
Thread.Sleep(3 * 1000); //等待页面加载完成
var logs = driver.Manage().Logs.GetLog("performance"); //获取所有performance日志
}
顺便放个Python代码做个对比：
caps = {
'browserName': 'chrome',
'loggingPrefs': {
'performance': 'Info', //启用performance日志，等级为Info即可
},
'goog:chromeOptions': {
'perfLoggingPrefs': {
'enableNetwork': True, //采集网络请求事件
},
'w3c': False,
},
}
driver = webdriver.Chrome(desired_capabilities=caps)
//TODO 获取日志
//.....
分析Logging：
我们从返回的日志列表里随便挑一个看看原始内容：
{[2022-08-03T08:47:31Z] [Info] {"message":{"method":"Network.responseReceived","params":{"frameId":"78D9BC6F0CBE162DA6779F410AA1500C","hasExtraInfo":true,"loaderId":"33814E6BD702343CF0A2A38C976C772F","requestId":"33814E6BD702343CF0A2A38C976C772F","response":{"connectionId":242,"connectionReused":false,"encodedDataLength":546,"fromDiskCache":false,"fromPrefetchCache":false,"fromServiceWorker":false,"headers":{"access-control-allow-credentials":"true","access-control-allow-headers":"Origin, X-Requested-With, Content-Type, multipart/form-data, Accept, Authorization","access-control-allow-methods":"POST, GET, PATCH, DELETE, PUT, OPTIONS","access-control-allow-origin":"*","access-control-max-age":"3600","cache-control":"no-cache,no-store","content-encoding":"gzip","content-language":"zh-CN","content-type":"text/html;charset=UTF-8","date":"Wed, 03 Aug 2022 08:47:33 GMT","hit":"bj-9153118133147527","server":"jfe","strict-transport-security":"max-age=86400","vary":"Accept-Encoding"},"mimeType":"text/html","protocol":"h2","remoteIPAddress":"106.39.169.120","remotePort":443,"responseTime":1.659516451658764e+12,"securityDetails":{"certificateId":0,"certificateTransparencyCompliance":"compliant","cipher":"AES_256_GCM","issuer":"GlobalSign RSA OV SSL CA 2018","keyExchange":"","keyExchangeGroup":"X25519","protocol":"TLS 1.3","sanList":["*.jd.com","*.360buy.com","*.360buyimg.com","*.3.cn","*.7fresh.com","*.baitiao.com","*.chinabank.com.cn","*.e.jd.com","*.jd.co.th","*.jddglobal.com","*.jd.hk","*.jd.id","*.jdpay.com","*.jd.ru","*.jdworldwide.com","*.jdx.com","*.joybuy.com","*.joybuy.es","*.jr.jd.com","*.k.jd.com","*.m.jd.com","*.m.yhd.com","*.shop.jd.com","*.wangyin.com","*.yhd.com","*.yiyaojd.com","360buy.com","360buyimg.com","3.cn","7fresh.com","baitiao.com","chinabank.com.cn","jd.co.th","jddglobal.com","jd.hk","jd.id","jdpay.com","jd.ru","jdworldwide.com","jdx.com","joybuy.com","joybuy.es","wangyin.com","yhd.com","yiyaojd.com","jd.com"],"signedCertificateTimestampList":[{"hashAlgorithm":"SHA-256","logDescription":"Sectigo 'Mammoth' CT log","logId":"6F5376AC31F03119D89900A45115FF77151C11D902C10029068DB2089A37D913","origin":"Embedded in certificate","signatureAlgorithm":"ECDSA","signatureData":"3045022017A2AC492303F50786758D0B4B63EEB8D031850832031FC5A43139C0CDA5EB4F0221009063F884220327718857A6897B87ED5D9F785FFC97F23BD45C84975A11DE721E","status":"Verified","timestamp":1.634109209345e+12},{"hashAlgorithm":"SHA-256","logDescription":"Google 'Argon2022' log","logId":"2979BEF09E393921F056739F63A577E5BE577D9C600AF8F94D5D265C255DC784","origin":"Embedded in certificate","signatureAlgorithm":"ECDSA","signatureData":"3045022071D6D51A59CAA1764E478598AA8EE34B628C8F856B09CDB8382E090CF5D6D97D022100A8FE17E028BB6D439387721974ED3629B9CC44C90AC524B505B9B2375C75CBB9","status":"Verified","timestamp":1.634109210136e+12},{"hashAlgorithm":"SHA-256","logDescription":"Sectigo 'Sabre' CT log","logId":"5581D4C2169036014AEA0B9B573C53F0C0E43878702508172FA3AA1D0713D30C","origin":"Embedded in certificate","signatureAlgorithm":"ECDSA","signatureData":"3045022015D94080264A3FCA83C0F3DE2B85A703384BB678FEBBE5408B4FF7D30BD40900022100DFBAB7992EE99420724CA35A5C2C252298B750994B0EAA98ACB22992F97D545E","status":"Verified","timestamp":1.634109209393e+12}],"subjectName":"*.jd.com","validFrom":1634109205,"validTo":1668410005},"securityState":"secure","status":200,"statusText":"","timing":{"connectEnd":96.834,"connectStart":19.521,"dnsEnd":19.521,"dnsStart":0,"proxyEnd":-1,"proxyStart":-1,"pushEnd":0,"pushStart":0,"receiveHeadersEnd":217.707,"requestTime":2272960.91089,"sendEnd":97.25,"sendStart":97.03,"sslEnd":96.829,"sslStart":55.726,"workerFetchStart":-1,"workerReady":-1,"workerRespondWithSettled":-1,"workerStart":-1},"url":"https://item.m.jd.com/product/10052422060501.html"},"timestamp":2272961.1294,"type":"Document"}},"webview":"78D9BC6F0CBE162DA6779F410AA1500C"}}
我们格式化一下，可以发现日志里已经包含了请求的大部分描述信息，我们需要遍历过滤出method为Network.responseReceived的日志，当然你也可以再根据其他的一些参数过滤出你要的请求
每个日志都有一个requestId，我们再通过该值调CDP命令[Network.getResponseBody]换取具体内容
{
"message": {
"method": "Network.responseReceived",
"params": {
"frameId": "78D9BC6F0CBE162DA6779F410AA1500C",
"hasExtraInfo": true,
"loaderId": "33814E6BD702343CF0A2A38C976C772F",
"requestId": "33814E6BD702343CF0A2A38C976C772F",
"response": {
"connectionId": 242,
"connectionReused": false,
"encodedDataLength": 546,
"fromDiskCache": false,
"fromPrefetchCache": false,
"fromServiceWorker": false,
"headers": {
"access-control-allow-credentials": "true",
"access-control-allow-headers": "Origin, X-Requested-With, Content-Type, multipart/form-data, Accept, Authorization",
"access-control-allow-methods": "POST, GET, PATCH, DELETE, PUT, OPTIONS",
"access-control-allow-origin": "*",
"access-control-max-age": "3600",
"cache-control": "no-cache,no-store",
"content-encoding": "gzip",
"content-language": "zh-CN",
"content-type": "text/html;charset=UTF-8",
"date": "Wed, 03 Aug 2022 08:47:33 GMT",
"hit": "bj-9153118133147527",
"server": "jfe",
"strict-transport-security": "max-age=86400",
"vary": "Accept-Encoding"
},
"mimeType": "text/html",
"protocol": "h2",
"remoteIPAddress": "106.39.169.120",
"remotePort": 443,
"responseTime": 1.659516451658764e+12,
"securityDetails": {
"certificateId": 0,
"certificateTransparencyCompliance": "compliant",
"cipher": "AES_256_GCM",
"issuer": "GlobalSign RSA OV SSL CA 2018",
"keyExchange": "",
"keyExchangeGroup": "X25519",
"protocol": "TLS 1.3",
"sanList": ["*.jd.com", "*.360buy.com", "*.360buyimg.com", "*.3.cn", "*.7fresh.com", "*.baitiao.com", "*.chinabank.com.cn", "*.e.jd.com", "*.jd.co.th", "*.jddglobal.com", "*.jd.hk", "*.jd.id", "*.jdpay.com", "*.jd.ru", "*.jdworldwide.com", "*.jdx.com", "*.joybuy.com", "*.joybuy.es", "*.jr.jd.com", "*.k.jd.com", "*.m.jd.com", "*.m.yhd.com", "*.shop.jd.com", "*.wangyin.com", "*.yhd.com", "*.yiyaojd.com", "360buy.com", "360buyimg.com", "3.cn", "7fresh.com", "baitiao.com", "chinabank.com.cn", "jd.co.th", "jddglobal.com", "jd.hk", "jd.id", "jdpay.com", "jd.ru", "jdworldwide.com", "jdx.com", "joybuy.com", "joybuy.es", "wangyin.com", "yhd.com", "yiyaojd.com", "jd.com"],
"signedCertificateTimestampList": [{
"hashAlgorithm": "SHA-256",
"logDescription": "Sectigo 'Mammoth' CT log",
"logId": "6F5376AC31F03119D89900A45115FF77151C11D902C10029068DB2089A37D913",
"origin": "Embedded in certificate",
"signatureAlgorithm": "ECDSA",
"signatureData": "3045022017A2AC492303F50786758D0B4B63EEB8D031850832031FC5A43139C0CDA5EB4F0221009063F884220327718857A6897B87ED5D9F785FFC97F23BD45C84975A11DE721E",
"status": "Verified",
"timestamp": 1.634109209345e+12
}, {
"hashAlgorithm": "SHA-256",
"logDescription": "Google 'Argon2022' log",
"logId": "2979BEF09E393921F056739F63A577E5BE577D9C600AF8F94D5D265C255DC784",
"origin": "Embedded in certificate",
"signatureAlgorithm": "ECDSA",
"signatureData": "3045022071D6D51A59CAA1764E478598AA8EE34B628C8F856B09CDB8382E090CF5D6D97D022100A8FE17E028BB6D439387721974ED3629B9CC44C90AC524B505B9B2375C75CBB9",
"status": "Verified",
"timestamp": 1.634109210136e+12
}, {
"hashAlgorithm": "SHA-256",
"logDescription": "Sectigo 'Sabre' CT log",
"logId": "5581D4C2169036014AEA0B9B573C53F0C0E43878702508172FA3AA1D0713D30C",
"origin": "Embedded in certificate",
"signatureAlgorithm": "ECDSA",
"signatureData": "3045022015D94080264A3FCA83C0F3DE2B85A703384BB678FEBBE5408B4FF7D30BD40900022100DFBAB7992EE99420724CA35A5C2C252298B750994B0EAA98ACB22992F97D545E",
"status": "Verified",
"timestamp": 1.634109209393e+12
}],
"subjectName": "*.jd.com",
"validFrom": 1634109205,
"validTo": 1668410005
},
"securityState": "secure",
"status": 200,
"statusText": "",
"timing": {
"connectEnd": 96.834,
"connectStart": 19.521,
"dnsEnd": 19.521,
"dnsStart": 0,
"proxyEnd": -1,
"proxyStart": -1,
"pushEnd": 0,
"pushStart": 0,
"receiveHeadersEnd": 217.707,
"requestTime": 2272960.91089,
"sendEnd": 97.25,
"sendStart": 97.03,
"sslEnd": 96.829,
"sslStart": 55.726,
"workerFetchStart": -1,
"workerReady": -1,
"workerRespondWithSettled": -1,
"workerStart": -1
},
"url": "https://item.m.jd.com/product/10052422060501.html"
},
"timestamp": 2272961.1294,
"type": "Document"
}
},
"webview": "78D9BC6F0CBE162DA6779F410AA1500C"
}
完整代码：
var option = new ChromeOptions();
option.SetLoggingPreference("performance",OpenQA.Selenium.LogLevel.Info); //启用performance日志，等级为Info即可
option.PerformanceLoggingPreferences = new ChromiumPerformanceLoggingPreferences() {
IsCollectingNetworkEvents = true //采集网络请求事件
};
using (ChromeDriver driver = new ChromeDriver(driverPath,option,TimeSpan.FromSeconds(5))) {
driver.Navigate().GoToUrl("https://item.m.jd.com/product/10052422060501.html");
Thread.Sleep(3 * 1000); //等待页面加载完成
var logs = driver.Manage().Logs.GetLog("performance").Where(o => o.Message.Contains("\"Network.responseReceived\""))；//获取所有performance日志，并过滤出所有类型为Network.responseReceived的日志
foreach (var log in logs) {
//日志找不到就会抛出异常，必须要捕获异常
try {
var json = JObject.Parse(log.Message);
var url = json["message"]["params"]["response"]["url"].ToString(); //请求url，可通过url过滤出你要的请求
var requestId = json["message"]["params"]["requestId"].ToString();
//利用RequestId做为参数，执行CDP命令获取日志详细内容。 踩坑警告：返回的是一个字典，需要转换为Dictionary<string,object>
var response = driver.ExecuteCdpCommand("Network.getResponseBody",new Dictionary<string,object>() {{ "requestId",requestId }}) as Dictionary<string,object>;
if (response.TryGetValue("body",out object? bodyObj) && bodyObj != null) {
string body = bodyObj.ToString();
Console.WriteLine($"输出Body内容：{body}");
}
} catch(Exception ex){
//记录错误日志
}
}
}
封装
为了以后方便复用，我封装了一个类
其中过滤条件的入参，可以根据实际情况自行修改，如果不需要对body内容进行过滤可以去掉这个参数，这样就不用每次等待拿到结果再过滤，性能会好很多
/// <summary>
/// Selenium网络请求日志帮助类
/// </summary>
public class NetworkLoggingHelper
{
static readonly Logger logger = NlogProvider.GetLogger(); /// <summary>
/// 开启网络请求日志
/// </summary>
/// <param name="option"></param>
public static void OpenNetworkPerformanceLogging(ref ChromeOptions option)
{
option.SetLoggingPreference("performance",OpenQA.Selenium.LogLevel.Info);
option.PerformanceLoggingPreferences = new ChromiumPerformanceLoggingPreferences() {
IsCollectingNetworkEvents = true
};
} /// <summary>
/// 获取网络请求数据
/// </summary>
/// <param name="driver"></param>
/// <param name="filter">过滤条件 入参1：请求的url | 入参2：请求的mimeType | 入参3：请求的body</param>
/// <returns></returns>
public static Dictionary<string,string> GetNetworkApiDatas(ChromeDriver driver,Func<string,string,string,bool> filter)
{
Dictionary<string,string> datas = new Dictionary<string,string>();
try {
var logs = driver.Manage().Logs.GetLog("performance")?.Where(o => o.Message.Contains("\"Network.responseReceived\""));
foreach (var log in logs) {
try {
var json = JObject.Parse(log.Message);
if (json["message"]["params"] == null || json["message"]["params"]["response"] == null) {
continue;
}
var url = json["message"]["params"]["response"]["url"].ToString();
var mimeType = json["message"]["params"]["response"]["mimeType"].ToString();
var requestId = json["message"]["params"]["requestId"].ToString();
var response = driver.ExecuteCdpCommand("Network.getResponseBody",new Dictionary<string,object>() {
{ "requestId",requestId }
}) as Dictionary<string,object>;
if (response != null && response.Count > 0) {
//是否base64编码
var isBase64Encode = false;
if (response.TryGetValue("base64Encoded",out object? base64Encoded) && base64Encoded != null) {
isBase64Encode = (bool)base64Encoded;
}
//获取响应内容
string body = string.Empty;
if (response.TryGetValue("body",out object? bodyObj) && bodyObj != null) {
body = bodyObj.ToString();
if (isBase64Encode) {
body = body.DecodeBase64(Encoding.UTF8);
}
}
//根据条件过滤，如果不需要body内容参与过滤条件判断，这个if语句可以移到获取response的上面，性能会好很多
if (filter.Invoke(url,mimeType,body)) {
datas.Add(url,body);
}
}
} catch (Exception ex) {
logger.Error(ex.Message);
}
}
} catch (Exception ex) {
logger.Error($"获取日志失败：{ex.Message}");
}
return datas;
}
}
调用示例：
var option = new ChromeOptions();
NetworkLoggingHelper.OpenNetworkPerformanceLogging(ref option); //开启日志
using (ChromeDriver driver = new ChromeDriver(driverPath,option,TimeSpan.FromSeconds(5))) {
driver.Navigate().GoToUrl("https://item.m.jd.com/product/10052422060501.html");
Thread.Sleep(3 * 1000); //等待页面加载完成 var datas = NetworkLoggingHelper.GetNetworkApiDatas(driver,(url,mimeType,body) => {
return url.Contains("//item.m.jd.com/product/") || mimeType.Contains("application/json") || body.Contains("windows.itemInfo");
});
Console.WriteLine(datas.Count);
}
Selenium工作原理
叙述一下selenium工作的过程
1.selenium client(python等语言编写的自动化测试脚本)初始化一个service服务，通过Webdriver启动浏览器驱动程序chromedriver.exe
2.通过RemoteWebDriver向浏览器驱动程序发送HTTP请求，浏览器驱动程序解析请求，打开浏览器，并获得sessionid，如果再次对浏览器操作需携带此id
3.打开浏览器，绑定特定的端口，把启动后的浏览器作为webdriver的remote server
3.打开浏览器后，所有的selenium的操作(访问地址，查找元素等)均通过RemoteConnection链接到remote server，然后使用execute方法调用_request方法通过urlib3向remote server发送请求
4.浏览器通过请求的内容执行对应动作
5.浏览器再把执行的动作结果通过浏览器驱动程序返回给测试脚本
6. webdriver.是 w3c 的标准协议。提供一组接口,用于发现和操作web文档中的DOM元素。
webdriver.是一系列的API.它给测试代码提供了定位和操作 wEB元素的能力。不同的开发语言有相应的wsbdriver.
↑↑↑↑ 该部分内容来自：https://www.cnblogs.com/xrxc/p/14776895.html
作者：Harry
原文出处：https://www.cnblogs.com/simendancer/articles/16546199.html
有些文本描述和图片源自网络，如有侵犯请私信告知
C#爬虫之通过Selenium获取浏览器请求响应结果的更多相关文章
- VS2008 C++ 利用WinHttp API获取Http请求/响应头部Header
http://www.cnblogs.com/LCCRNblog/p/3833472.html 这一篇博客中,实现了获取http请求/响应后的html源码,现在需要获取http请求/响应的头部Head ...
- Spider-Python爬虫之使用Selenium模拟浏览器行为
分析 他的代码比较简单,主要有以下的步骤:使用BeautifulSoup库,打开百度贴吧的首页地址,再解析得到id为new_list标签底下的img标签,最后将img标签的图片保存下来. header ...
- selenium.获取浏览器大小、设置浏览器位置、最大化浏览器
此篇博客学习控制浏览器的api,分别有: get_window_size() 获取浏览器大小 set_window_size() 设置浏览器位置 get_window_position() 获取浏览器 ...
- LoadRunner 获取接口请求响应信息
Action() { int nHttpRetCode; // 默认最大长度为256,get请求需注意缓存问题,需要根据content-length进行修改 web_set_max_html_para ...
- [转] LoadRunner 获取接口请求响应信息
Action() { int nHttpRetCode; // 默认最大长度为256,get请求需注意缓存问题,需要根据content-length进行修改 web_set_max_html_para ...
- 爬虫模块介绍--selenium （浏览器自动化测试工具，模拟可以调用浏览器模拟人操作浏览器）
selenium主要的用途就是控制浏览器,模仿真人操作浏览器的行为 模块安装:pip3 install selenium 需要控制的浏览器 from selenium import webdriver ...
- 爬虫实战--使用Selenium模拟浏览器抓取淘宝商品美食信息
from selenium import webdriver from selenium.webdriver.common.by import By from selenium.common.exce ...
- [技巧篇]11.JavaScript原生态如何获取浏览器请求地址中的参数
var getAccessParams = function(){ var i,ilen,strs,keyName,keyValue, params={}, path = window.locatio ...
- selenium获取浏览器控制台日志
public void logsTest(){ WebDriver driver = null; try { System.setProperty("webdriver.chrome.dri ...
随机推荐
- Spring Boot 2.7.0发布，2.5停止维护，节奏太快了吧
这几天是Spring版本日,很多Spring工件都发布了新版本, Spring Framework 6.0.0 发布了第 4 个里程碑版本,此版本包含所有针对 5.3.20 的修复补丁,以及特定于 6 ...
- 详解TCP三次握手（建立TCP连接过程）
在讲述TCP三次握手,即建立TCP连接的过程之前,需要先介绍一下TCP协议的包结构. 这里只对涉及到三次握手过程的字段做解释 (1) 序号(Sequence number) 我们通过 TCP 协议将数 ...
- 20 HTTP 长连接与短连接
20 HTTP 长连接与短连接 每日一句 纸上得来终觉浅,绝知此事要躬行. 每日一句 Never give up until the fight is over. 永远不要放弃,要一直战斗到最后一秒. ...
- 记一次Tomcat卡死在 Deploying web application 步骤的问题
公司有一个历史的遗留项目是传统的MVC架构的前后不分离的项目,一开始使用JDK1.7写的,后来前一阵老板说想在这个远古项目上加点功能,顺带换换皮,于是乎一帮程序员们就用JDK1.8重新翻新了一遍项目顺 ...
- 盘点微信小程序跨页面传值的若干方式
直接给大家上干货 1.跳转页面传递参数 pageA.wxml <button type="primary" bindtap="jumpTo">点击跳 ...
- JAVA - 启动线程有哪几种方式
JAVA - 启动线程有哪几种方式 一.继承Thread类创建线程类 (1)定义Thread类的子类,并重写该类的run方法,该run方法的方法体就代表了线程要完成的任务.因此把run()方法称为执行 ...
- 拥抱Spring全新OAuth解决方案
以下全文 Spring Authorization Server 简称为: SAS 背景 Spring 团队正式宣布 Spring Security OAuth 停止维护,该项目将不会再进行任何的迭代 ...
- SCI论文写作注意事项
1. 先写结论:(划定范围,以防添加无效的内容) 并非一开始就把整个结论都写出来,而是把
- JMeter - 生成随机数/随机字符串/随机变量/随机日期
1. Random - 随机数 1.1 作用 1.2 声明 1.3 例子 2. __RandomDate - 随机日期 2.1 作用 2.2 声明参数 2.3 例子 3. RandomString - ...
- JS：逗号运算符
逗号运算符: 会把逗号隔开的表达式全部执行 最后一个运行的表达式的结果就是逗号运算符的结果 例: var a = (1, 2, 3, 4, 5, 6); console.log(a); //6 隐 ...