问个小问题

[橘子皮...]

        System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

	Try
		sUrl = "https://quizlet.com/": Link = ""
		xmlhttp = DirectCast(WebRequest.Create(sUrl), HttpWebRequest)
		xmlhttp.Timeout = 6000 : xmlhttp.AllowAutoRedirect = False 
		xmlhttp.Method = "GET": xmlhttp.KeepAlive = False
		xmlhttp.Host = "quizlet.com"
		xmlhttp.Headers.Add("upgrade-insecure-requests", "1")
		xmlhttp.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36"
		xmlhttp.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"
		xmlhttp.Headers.Add("sec-fetch-site", "none")
		xmlhttp.Headers.Add("sec-fetch-mode", "navigate")
		xmlhttp.Headers.Add("sec-fetch-dest", "document")
		xmlhttp.Headers.Add("accept-language", "zh-CN,zh;q=0.9,en;q=0.8,fr;q=0.7,zh-TW;q=0.6,ja;q=0.5")
		'xmlhttp.Headers.Add("accept-encoding", "gzip, deflate")
		Using rep As HttpWebResponse = xmlhttp.GetResponse()
			Link = rep.GetResponseHeader("Location")
		End Using
	Catch ex As WebException : If ex.Status <> WebExceptionStatus.Timeout Then Throw
	Catch ex As Exception : Throw
	Finally : xmlhttp.Abort() : xmlhttp = Nothing
	End Try

模拟抓包抓到的发出去后返回 远程服务器返回错误: (403) 已禁止。
不知道什么原因导致的，请会的指点12

[X-i-n]

大概率是COOKIE上加验证了。第一次请求以后，把cookie存下来，后边所有请求都带上它们。

[极客诗人]

如上所说 你可以对比后几次请求的头部标签...