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This article mainly explains "how C # sends Http requests through GET/POST". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's ideas to study and learn "how C # sends Http requests through GET/POST".

Catalogue

The difference between the two:

Parameters.

The size of the transmitted data

Security.

Get request

Post request

This paper introduces two ways of http request, get and post. And use C # language to realize, how to request url and get the returned data

Difference between the two: parameters

Get requests to simply encode the submitted data and send part of the url to the server

Like url:Http://127.0.0.1/login.jsp?Name=zhangshi&Age=30&Submit=%cc%E+%BD%BB.

Therefore, there are some security risks in the data submitted by get request. If you are using operations that require high security (such as user login and payment), you should use post. Get request is the default http request method. We usually use the get method to get form data.

The POST request places the requested data in the body of the HTTP request packet. The item=bandsaw above is the actual data transfer.

The size of the transmitted data

GET, specific browsers and servers have limits on the length of URL. Therefore, when using GET requests, the transmission of data is limited by the length of the URL.

POST, which is not URL, is not restricted in theory, but in fact, each server will specify a limit on the size of the data submitted by POST. Apache and IIS have their own configurations.

Security.

POST is more secure than GET. The security here refers to the real security, and unlike the security method mentioned by GET above, the security mentioned above simply does not modify the server's data. For example, during the login operation, through the GET request, the user name and password will be exposed on the URL, because the login page may be cached by the browser and others may view the browser history, the user name and password can be easily obtained by others. In addition, the data submitted by GET requests may also cause Cross-site request frogery attacks

The GET,POST,SOAP protocol in HTTP runs on HTTP.

Get request

Request class

/ Get request / string public static string GetHttpResponse (string url, int Timeout) {HttpWebRequest request = (HttpWebRequest) WebRequest.Create (url); request.Method = "GET"; request.ContentType = "text/html;charset=UTF-8"; request.UserAgent = null; request.Timeout = Timeout; HttpWebResponse response = (HttpWebResponse) request.GetResponse (); Stream myResponseStream = response.GetResponseStream () StreamReader myStreamReader = new StreamReader (myResponseStream, Encoding.GetEncoding ("utf-8")); string retString = myStreamReader.ReadToEnd (); myStreamReader.Close (); myResponseStream.Close (); return retString;}

Call method

String url= "Http://127.0.0.1/login.jsp?Name=zhangshi&Age=30&Submit=%cc%E+%BD%BB"; string res = HttpHelper.GetHttpResponse (url, 6000); if (res! = null) {T mes = JsonHelper.DeserializeJsonToObject (res)} Post request

/ / create HTTP request public static HttpWebResponse CreatePostHttpResponse (string url, IDictionary parameters, int timeout, string userAgent, CookieCollection cookies) in POST mode {HttpWebRequest request = null; / / if sending HTTPS request if (url.StartsWith ("https", StringComparison.OrdinalIgnoreCase)) {request = WebRequest.Create (url) as HttpWebRequest } else {request = WebRequest.Create (url) as HttpWebRequest;} request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; / / set proxy UserAgent and timeout / / request.UserAgent = userAgent; / / request.Timeout = timeout If (cookies! = null) {request.CookieContainer = new CookieContainer (); request.CookieContainer.Add (cookies);} / send POST data if (! (parameters = = null | | parameters.Count = = 0)) {StringBuilder buffer = new StringBuilder (); int I = 0 Foreach (string key in parameters.Keys) {if (I > 0) {buffer.AppendFormat ("& {0} = {1}", key, parameters [key]) } else {buffer.AppendFormat ("{0} = {1}", key, parameters [key]); byte [] data = Encoding.ASCII.GetBytes (buffer.ToString ()) Using (Stream stream = request.GetRequestStream ()) {stream.Write (data, 0, data.Length);} string [] values = request.Headers.GetValues ("Content-Type"); return request.GetResponse () as HttpWebResponse } / public static string GetResponseString (HttpWebResponse webresponse) {using (Stream s = webresponse.GetResponseStream ()) {StreamReader reader = new StreamReader (s, Encoding.UTF8); return reader.ReadToEnd ();}}

Call method

/ Parameter pIDictionary parameters = new Dictionary (); parameters.Add ("p", HttpUtility.UrlEncode (p)); / / http request System.Net.HttpWebResponse res = HttpHelper.CreatePostHttpResponse (url, parameters, 3000, null, null); if (res = = null) {Response.Redirect ("RequestFailed.aspx?result= has made an error, possibly because your network environment is poor, unstable, or the security software forbids access to the network. You can revisit the network when the network is good or when the security software is turned off.") ;} else {/ / get the returned data into the string string mes = HttpHelper.GetResponseString (res); T model = JsonHelper.DeserializeJsonToObject (mes) } Thank you for your reading. the above is the content of "how to send Http requests through GET/POST". After the study of this article, I believe you have a deeper understanding of how C# sends Http requests through GET/POST, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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