如何使HTTP POST Web请求
如何使用POST方法发出HTTP请求并发送一些数据？ 我可以做GET请求，但不知道如何做POST 。
有几种方法可以执行HTTP GET和POST请求：
方法A：HttpClient
可用于：.NET Framework 4.5+，.NET Standard 1.1+，.NET Core 1.0+
目前首选的方法。 asynchronous。 其他平台的可移植版本通过NuGet提供 。
using System.Net.Http;
build立
build议为您的应用程序的生命周期实例化一个HttpClient并共享它。
private static readonly HttpClient client = new HttpClient();
POST
var values = new Dictionary<string, string> { { "thing1", "hello" }, { "thing2", "world" } }; var content = new FormUrlEncodedContent(values); var response = await client.PostAsync("http://www.example.com/recepticle.aspx", content); var responseString = await response.Content.ReadAsStringAsync();
得到
var responseString = await client.GetStringAsync("http://www.example.com/recepticle.aspx");
方法B：第三方库
RestSharp
尝试并testing了与REST API交互的库。 便携。 通过NuGet提供 。
Flurl.Http
新的图书馆运动stream畅的API和testing助手。 引擎盖下的HttpClient。 便携。 通过NuGet提供 。
using Flurl.Http;
POST
var responseString = await "http://www.example.com/recepticle.aspx" .PostUrlEncodedAsync(new { thing1 = "hello", thing2 = "world" }) .ReceiveString();
得到
var responseString = await "http://www.example.com/recepticle.aspx" .GetStringAsync();
方法C：遗留
可用于：.NET Framework 1.1+，.NET Standard 2.0+，.NET Core 1.0+
using System.Net; using System.Text; // for class Encoding using System.IO; // for StreamReader
POST
var request = (HttpWebRequest)WebRequest.Create("http://www.example.com/recepticle.aspx"); var postData = "thing1=hello"; postData += "&thing2=world"; var data = Encoding.ASCII.GetBytes(postData); request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; request.ContentLength = data.Length; using (var stream = request.GetRequestStream()) { stream.Write(data, 0, data.Length); } var response = (HttpWebResponse)request.GetResponse(); var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
得到
var request = (HttpWebRequest)WebRequest.Create("http://www.example.com/recepticle.aspx"); var response = (HttpWebResponse)request.GetResponse(); var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
方法D：WebClient（也是现在的传统）
可用于：.NET Framework 1.1+，.NET Standard 2.0+，.NET Core 2.0+
using System.Net; using System.Collections.Specialized;
POST
using (var client = new WebClient()) { var values = new NameValueCollection(); values["thing1"] = "hello"; values["thing2"] = "world"; var response = client.UploadValues("http://www.example.com/recepticle.aspx", values); var responseString = Encoding.Default.GetString(response); }
得到
using (var client = new WebClient()) { var responseString = client.DownloadString("http://www.example.com/recepticle.aspx"); }
简单的GET请求
using System.Net; ... using (var wb = new WebClient()) { var response = wb.DownloadString(url); }
简单的POST请求
using System.Net; using System.Collections.Specialized; ... using (var wb = new WebClient()) { var data = new NameValueCollection(); data["username"] = "myUser"; data["password"] = "myPassword"; var response = wb.UploadValues(url, "POST", data); }
MSDN有一个示例。
using System; using System.IO; using System.Net; using System.Text; namespace Examples.System.Net { public class WebRequestPostExample { public static void Main() { // Create a request using a URL that can receive a post. WebRequest request = WebRequest.Create("http://www.contoso.com/PostAccepter.aspx"); // Set the Method property of the request to POST. request.Method = "POST"; // Create POST data and convert it to a byte array. string postData = "This is a test that posts this string to a Web server."; byte[] byteArray = Encoding.UTF8.GetBytes(postData); // Set the ContentType property of the WebRequest. request.ContentType = "application/x-www-form-urlencoded"; // Set the ContentLength property of the WebRequest. request.ContentLength = byteArray.Length; // Get the request stream. Stream dataStream = request.GetRequestStream(); // Write the data to the request stream. dataStream.Write(byteArray, 0, byteArray.Length); // Close the Stream object. dataStream.Close(); // Get the response. WebResponse response = request.GetResponse(); // Display the status. Console.WriteLine(((HttpWebResponse)response).StatusDescription); // Get the stream containing content returned by the server. dataStream = response.GetResponseStream(); // Open the stream using a StreamReader for easy access. StreamReader reader = new StreamReader(dataStream); // Read the content. string responseFromServer = reader.ReadToEnd(); // Display the content. Console.WriteLine(responseFromServer); // Clean up the streams. reader.Close(); dataStream.Close(); response.Close(); } } }
您需要使用WebRequest类和GetRequestStream方法。
这是一个例子。
简单的（单线程，没有错误检查，不等待回应）解决scheme，我发现迄今
(new WebClient()).UploadStringAsync(new Uri(Address), dataString);
谨慎使用！
这是一个以JSON格式发送/接收数据的完整实例，我使用了VS2013 Express Edition
using System; using System.Collections.Generic; using System.Data; using System.Data.OleDb; using System.IO; using System.Linq; using System.Net.Http; using System.Text; using System.Threading.Tasks; using System.Web.Script.Serialization; namespace ConsoleApplication1 { class Customer { public string Name { get; set; } public string Address { get; set; } public string Phone { get; set; } } public class Program { private static readonly HttpClient _Client = new HttpClient(); private static JavaScriptSerializer _Serializer = new JavaScriptSerializer(); static void Main(string[] args) { Run().Wait(); } static async Task Run() { string url = "http://www.example.com/api/Customer"; Customer cust = new Customer() { Name = "Example Customer", Address = "Some example address", Phone = "Some phone number" }; var json = _Serializer.Serialize(cust); var response = await Request(HttpMethod.Post, url, json, new Dictionary<string, string>()); string responseText = await response.Content.ReadAsStringAsync(); List<YourCustomClassModel> serializedResult = _Serializer.Deserialize<List<YourCustomClassModel>>(responseText); Console.WriteLine(responseText); Console.ReadLine(); } /// <summary> /// Makes an async HTTP Request /// </summary> /// <param name="pMethod">Those methods you know: GET, POST, HEAD, etc...</param> /// <param name="pUrl">Very predictable...</param> /// <param name="pJsonContent">String data to POST on the server</param> /// <param name="pHeaders">If you use some kind of Authorization you should use this</param> /// <returns></returns> static async Task<HttpResponseMessage> Request(HttpMethod pMethod, string pUrl, string pJsonContent, Dictionary<string, string> pHeaders) { var httpRequestMessage = new HttpRequestMessage(); httpRequestMessage.Method = pMethod; httpRequestMessage.RequestUri = new Uri(pUrl); foreach (var head in pHeaders) { httpRequestMessage.Headers.Add(head.Key, head.Value); } switch (pMethod.Method) { case "POST": HttpContent httpContent = new StringContent(pJsonContent, Encoding.UTF8, "application/json"); httpRequestMessage.Content = httpContent; break; } return await _Client.SendAsync(httpRequestMessage); } } }
