Summary of reptile knowledge points

One , Get the html file

Use webClient Get web information , This method passes in url You can get html String

public static string HttpPost(string url, string paraJsonStr)
        {
            WebClient webClient = new WebClient();
            webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
            byte[] postData = System.Text.Encoding.UTF8.GetBytes(paraJsonStr);
            byte[] responseData = webClient.UploadData(url, "POST", postData);
            string returnStr = System.Text.Encoding.UTF8.GetString(responseData);
            return returnStr;

        }

Two , Regular matching

 MatchCollection matches = Regex.Matches(str, @">(.*)</h1>");
            foreach (Match match in matches)
            {
                GroupCollection groups = match.Groups;
               //group[1] It's the content 
                Console.WriteLine(groups[1].Value);
            }

The dictionary form  

Dictionary<string, string> resultDict = new Dictionary<string, string>();
foreach (Match matchedGroup in Regex.Matches(str, @"<p>(?<key>.*)</p>\n<ul>\n(?<value>[\w\W\n]*?)</ul>"))
            {
                Console.WriteLine(matchedGroup.Groups["key"].Value);
                if (matchedGroup.Groups["key"].Value.Contains("hahhaha"))
                {
                    resultDict.Add(matchedGroup.Groups["key"].Value, matchedGroup.Groups["value"].Value);
                }
                
            }

3、 ... and , write file

write in txt file

using (StreamWriter sw = new StreamWriter($"C:\\hhaha.txt"))
            {
                resultDict.ToList().ForEach(x => { sw.WriteLine($"{x.Key}"); sw.WriteLine($"{x.Value}"); });
            }

write in csv file , among new StreamWriter($" route ",true) This true It means that the existing file should not be created , This file does not exist , You need to create this file

 using (StreamWriter sw = new StreamWriter($"C:\\Users\\haha1.CSV", true))
                {
                   
                    if (type == "people")
                    {
                        
                        sw.WriteLine("name," + name);
//aValue It's a list, There are commas that jump to multiple columns 
                        aValue.ToList().ForEach(x => { sw.WriteLine("hobby," + (x)); });
                    }else if(type== "animals")
                    {
                        
                        sValue.ToList().ForEach(x => { sw.WriteLine(" looks ," + (x)); });
                        sw.WriteLine("");
                     
                    }
                    else
                    {

                    }

                }

This adds a new line to the file

//File.AppendAllLines($"C:\\Users\\hobby.CSV", Value.ToArray());