前言 ，想利用小程序导航页面来提升网站的流量，找到 www.xcxdh666.com 该小程序导航网站。
分析网页
1 发现网站其实也是用异步分页请求加载数据的 ，所以根本用不着xpath 解析html，直接分析其请求url
2点击加载更多找到请求，发现其实就 pageNum ,cagegory 两个参数
3所以直接请求url 带入参数,分析起返回json结果
编写代码
1 首先建立接收类型
public class XcxApplet
{
public int id { get; set; }
public string categoryName { get; set; }
public string name { get; set; }
public string saomaUrl { get; set; }
public string sum { get; set; }
public string logoUrl { get; set; }
}
public class Result
{
public List<XcxApplet> dataList { get; set; }
public string category { get; set; }
public int status { get; set; }
public int pageNum { get; set; }
}
2 封装请求页面方法
public static string GetPostPage(this string posturl, string postData)
{
Encoding encoding = Encoding.UTF8;
byte[] data = null;
if (!string.IsNullOrEmpty(postData)) data = encoding.GetBytes(postData);
try
{
// 设置参数
var request = WebRequest.Create(posturl) as HttpWebRequest;
if (request == null) return string.Empty;
var cookieContainer = new CookieContainer();
request.CookieContainer = cookieContainer;
request.AllowAutoRedirect = true;
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
if (data != null)
{
request.ContentLength = data.Length;
Stream outstream = request.GetRequestStream();
outstream.Write(data, 0, data.Length);
outstream.Close();
}
//发送请求并获取相应回应数据
var response = request.GetResponse() as HttpWebResponse;
if (response == null) return string.Empty;
//直到request.GetResponse()程序才开始向目标网页发送Post请求
Stream instream = response.GetResponseStream();
if (instream == null) return string.Empty;
var sr = new StreamReader(instream, encoding);
//返回结果网页（html）代码
string content = sr.ReadToEnd();
string err = string.Empty;
//Response.Write(content);
return content;
}
catch (Exception ex)
{
string err = ex.Message;
return string.Empty;
}
}
3 图片url处理 思路就是要将其返回的url 请求下载到本地或者上传到自己对应的图片服务器，
我这里是用七牛云存储img的 ，这里你可以改成下载到本地 返回本地的url就好。
public string QiniuUplod(string imgurl)
{
var accessKey = "你的accesskey";
var secretKey = "你的secretkey";
// 生成(上传)凭证时需要使用此Mac
// 这个示例单独使用了一个Settings类，其中包含AccessKey和SecretKey
// 实际应用中，请自行设置您的AccessKey和SecretKey
Mac mac = new Mac(accessKey, secretKey);
string bucket = "siyouku";
string saveKey = imgurl.Substring(imgurl.LastIndexOf('/')+1,imgurl.Length- imgurl.LastIndexOf('/')-1);
// 使用前请确保AK和BUCKET正确，否则此函数会抛出异常(比如code612/631等错误)
Qiniu.Common.Config.AutoZone(accessKey, bucket, false);
// 上传策略，参见
// https://developer.qiniu.com/kodo/manual/put-policy
PutPolicy putPolicy = new PutPolicy();
// 如果需要设置为"覆盖"上传(如果云端已有同名文件则覆盖)，请使用 SCOPE = "BUCKET:KEY"
putPolicy.Scope = bucket + ":" + saveKey;
putPolicy.Scope = bucket;
// 上传策略有效期(对应于生成的凭证的有效期)
putPolicy.SetExpires(3600);
// 上传到云端多少天后自动删除该文件，如果不设置（即保持默认默认）则不删除
//putPolicy.DeleteAfterDays = 1;
// 生成上传凭证，参见
// https://developer.qiniu.com/kodo/manual/upload-token
string jstr = putPolicy.ToJsonString();
string token = Auth.CreateUploadToken(mac, jstr);
try
{
var wReq = System.Net.WebRequest.Create(imgurl) as System.Net.HttpWebRequest;
var resp = wReq.GetResponse() as System.Net.HttpWebResponse;
using (var stream = resp.GetResponseStream())
{
// 请不要使用UploadManager的UploadStream方法，因为此流不支持查找(无法获取Stream.Length)
// 请使用FormUploader或者ResumableUploader的UploadStream方法
FormUploader fu = new FormUploader();
var result = fu.UploadStream(stream, saveKey, token);
var x = Newtonsoft.Json.JsonConvert.DeserializeObject<QiniuResult>(result.Text);
return $"http://img.siyouku.cn/{x.key}";
}
}
catch (Exception ex)
{
return "";
}
}
4 最后是请求主体方法
public ActionResult GetxcxList()
{
Stopwatch watch = new Stopwatch();//监控抓取耗时
watch.Start();
//https://www.xcxdh666.com/pageList.htm?pageNum=0 dataList
var result = new Result();
for (int j = 0; j <54; j++)
{
string url =
$"https://www.xcxdh666.com/pageList.htm?pageNum={j}";
var str = url.GetPostPage(null);//HttpWebRequest 请求页面
if (str != null)
{
result = str.JsonConvert<Result>(); //string 的序列化扩展方法
}
result.dataList.ForEach(i =>
{
if (!Db.Applet.Any(x => x.Name == i.name))//判断重复插入
{
var x = new Applet()
{
CategoryName = string.IsNullOrEmpty(i.categoryName) ? "其它" : i.categoryName,
Name = i.name,
SaomiaoUrl = QiniuUplod($"http://img.xcxdh666.com/wxappnav/{i.saomaUrl}"),
Summary = i.sum,
LogoUrl = QiniuUplod($"http://img.xcxdh666.com/wxappnav/{i.logoUrl}"),
SortNum = j,
CreateUser = "wenqing",
CreateTime = DateTime.Now
};
Db.Applet.Add(x);
}
});
Db.SaveChanges();
}
watch.Stop();
return Content("爬取完成！本次请求总共耗时："+ watch.ElapsedMilliseconds);
}
}
ok 到这里就全部抓取完成
这里附上 展示地址 http://siyouku.cn/Applet
本文永久更细地址：http://siyouku.cn/article/6806.html