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，发现其实就是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;
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川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Setting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="siyoku";
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
Qiniu.Common.Config.AutoZone(accessKey,bucket,false);
//上传策略
PutPolicy putPolicy=new PutPolicy();
putPolicy.Scope=bucket+":"+saveKey;
putPolicy.Scope=bucket;
putPolicy.SetExpires(3600);
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())
{
FormUploader fu= new FormUploader;
var result=fu.UploadStream(stream,saveKey,token);
var x=Newtonsoft.Json.JsonConvert.DeserializeObject<QiniuResult>(result.Text);
return $"http://img.siyouku.cn/{x.key}";
}
}
catch (Exception ex)
{
return "";
}
}
4 最后是请求主体方法
public ActionResult GetxcxList()
{
Stopwatch watch=new Stopwatch();
watch.Start();
var result=new Result();
for(int j=0;j<54;j++)
{
string url=$"https://www.xcxdh666.com/pageList.htm?pageNum={j}";
var str=url.GetPostPage(null);
if(str !=null)
{
result=str.JsonConvert<Result>();
}
result.dataList.ForEach(i=>
{
if(!Db.Applet.Any(x=>x.Name==i.name))
{
var x=new Applet()
{
CategoryName=string.IsNullOrEmpty(i.categoryName)?"其它":i.categoryName,
Name=i.name,
SaomiaoUrl=QiniuUpload($"http://img.xcxdh666.com/wxppnav/{i.saomaUrl}",
summary=i.sum,
LogoUrl=QiniuUpload($"http://img.xcxdh666.com/wxappnav/{i.logoUrl}"),
SortNum=j,
CreateUser="wenqing",
CreateTime=DateTime.Now
};
Db.Applet.Add(x);
}
});
Db.SaveChanges();
}
watch.Stop();
return Content("派取完成!本次请求总共耗时:"+watch.ElapsedMilliseconds);
}
}