Canonical: Wie kann ich eine HTTP-Anfrage stellen und einige Daten mit der POST
-Methode senden? Ich kann GET
anfordern, habe aber keine Ahnung, wie ich POST
erstellen soll.
Es gibt verschiedene Möglichkeiten, HTTP-Anforderungen für GET
und POST
auszuführen:
Methode A: HttpClient (bevorzugt)
Dies ist ein Wrapper um HttpWebRequest
. Vergleiche mit WebClient
.
Verfügbar in: .NET Framework 4.5+, .NET Standard 1.1+, .NET Core 1.0+
Derzeit der bevorzugte Ansatz. Asynchron. Portable Version für andere Plattformen verfügbar über NuGet .
using System.Net.Http;
Setup
Es ist empfohlen , eine HttpClient
für die Lebensdauer Ihrer Anwendung zu instanziieren und diese zu teilen.
private static readonly HttpClient client = new HttpClient();
Siehe HttpClientFactory
für eine Abhängigkeitsinjektionslösung.
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();
GET
var responseString = await client.GetStringAsync("http://www.example.com/recepticle.aspx");
Methode B: Bibliotheken von Drittanbietern
Bewährte Bibliothek für die Interaktion mit REST APIs. Tragbar. Verfügbar über NuGet .
Neuere Bibliothek mit einer fließenden API und Testhilfen. HttpClient unter der Haube. Tragbar. Verfügbar über NuGet .
using Flurl.Http;
POST
var responseString = await "http://www.example.com/recepticle.aspx"
.PostUrlEncodedAsync(new { thing1 = "hello", thing2 = "world" })
.ReceiveString();
GET
var responseString = await "http://www.example.com/recepticle.aspx"
.GetStringAsync();
Methode C: HttpWebRequest (Nicht empfohlen für neue Arbeiten)
Verfügbar in: .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=" + Uri.EscapeDataString("hello");
postData += "&thing2=" + Uri.EscapeDataString("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();
GET
var request = (HttpWebRequest)WebRequest.Create("http://www.example.com/recepticle.aspx");
var response = (HttpWebResponse)request.GetResponse();
var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
Methode D: WebClient (Nicht für neue Arbeiten empfohlen)
Dies ist ein Wrapper um HttpWebRequest
. Vergleiche mit HttpClient
.
Verfügbar in: .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);
}
GET
using (var client = new WebClient())
{
var responseString = client.DownloadString("http://www.example.com/recepticle.aspx");
}
Einfache GET-Anfrage
using System.Net;
...
using (var wb = new WebClient())
{
var response = wb.DownloadString(url);
}
Einfache POST Anfrage
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);
string responseInString = Encoding.UTF8.GetString(response);
}
MSDN hat eine Stichprobe.
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();
}
}
}
Dies ist ein vollständiges Arbeitsbeispiel für das Senden/Empfangen von Daten im JSON-Format. Ich habe die VS2013 Express Edition verwendet
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);
}
}
}
Hier gibt es einige wirklich gute Antworten. Lassen Sie mich einen anderen Weg veröffentlichen, um Ihre Header mit dem WebClient () zu setzen. Ich werde Ihnen auch zeigen, wie Sie einen API-Schlüssel festlegen.
var client = new WebClient();
string credentials = Convert.ToBase64String(Encoding.ASCII.GetBytes(userName + ":" + passWord));
client.Headers[HttpRequestHeader.Authorization] = $"Basic {credentials}";
//If you have your data stored in an object serialize it into json to pass to the webclient with Newtonsoft's JsonConvert
var encodedJson = JsonConvert.SerializeObject(newAccount);
client.Headers.Add($"x-api-key:{ApiKey}");
client.Headers.Add("Content-Type:application/json");
try
{
var response = client.UploadString($"{apiurl}", encodedJson);
//if you have a model to deserialize the json into Newtonsoft will help bind the data to the model, this is an extremely useful trick for GET calls when you have a lot of data, you can strongly type a model and dump it into an instance of that class.
Response response1 = JsonConvert.DeserializeObject<Response>(response);
Einfache (Einzeiler, keine Fehlerprüfung, keine Wartezeit auf Antwort) Lösung, die ich bisher gefunden habe
(new WebClient()).UploadStringAsync(new Uri(Address), dataString);
mit vorsicht verwenden!
Diese Lösung verwendet nur Standard-.NET-Aufrufe.
Geprüft:
Referenz:
// Add a Reference to the Assembly System.Web
Code:
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web;
private async Task<WebResponse> CallUri(string url, TimeSpan timeout)
{
var uri = new Uri(url);
NameValueCollection rawParameters = HttpUtility.ParseQueryString(uri.Query);
var parameters = new Dictionary<string, string>();
foreach (string p in rawParameters.Keys)
{
parameters[p] = rawParameters[p];
}
var client = new HttpClient { Timeout = timeout };
HttpResponseMessage response;
if (parameters.Count == 0)
{
response = await client.GetAsync(url);
}
else
{
var content = new FormUrlEncodedContent(parameters);
string urlMinusParameters = uri.OriginalString.Split('?')[0]; // Parameters always follow the '?' symbol.
response = await client.PostAsync(urlMinusParameters, content);
}
var responseString = await response.Content.ReadAsStringAsync();
return new WebResponse(response.StatusCode, responseString);
}
private class WebResponse
{
public WebResponse(HttpStatusCode httpStatusCode, string response)
{
this.HttpStatusCode = httpStatusCode;
this.Response = response;
}
public HttpStatusCode HttpStatusCode { get; }
public string Response { get; }
}
Aufruf ohne Parameter (verwendet ein "GET" hinter den Kulissen):
var timeout = TimeSpan.FromSeconds(300);
WebResponse response = await this.CallUri("http://www.google.com/", timeout);
if (response.HttpStatusCode == HttpStatusCode.OK)
{
Console.Write(response.Response); // Print HTML.
}
Aufruf mit Parametern (verwendet einen "POST" hinter den Kulissen):
var timeout = TimeSpan.FromSeconds(300);
WebResponse response = await this.CallUri("http://example.com/path/to/page?name=ferret&color=purple", timeout);
if (response.HttpStatusCode == HttpStatusCode.OK)
{
Console.Write(response.Response); // Print HTML.
}
Bei Verwendung von Windows.Web.Http Namespace schreiben wir für POST anstelle von FormUrlEncodedContent HttpFormUrlEncodedContent. Die Antwort ist auch der Typ von HttpResponseMessage. Der Rest ist, wie Evan Mulawski schrieb.
Sie können IEnterprise.Easy-HTTP verwenden, da Klassenanalyse und Abfrageerstellung integriert wurden:
await new RequestBuilder<ExampleObject>()
.SetHost("https://httpbin.org")
.SetContentType(ContentType.Application_Json)
.SetType(RequestType.Post)
.SetModelToSerialize(dto)
.Build()
.Execute();
Ich bin der Autor der Bibliothek, also zögern Sie nicht, Fragen zu stellen oder den Code in github zu überprüfen
Wenn Sie eine flüssige API mögen, können Sie Tiny.RestClient verwenden. Es ist verfügbar unter Nuget
var client = new TinyRestClient(new HttpClient(), "http://MyAPI.com/api");
// POST
var city = new City() { Name = "Paris", Country = "France" };
// With content
var response = await client.PostRequest("City", city)
.ExecuteAsync<bool>();
Ich hoffe, das hilft!