I am doing a bit of research into building a program to use the Australian crypto trading platform Coinspot. I have used API's in the past but barley used "POST" method, Coinspots information and documentation is sooooooo poor (probs because they don't want you to use it) but i figured ill give it a whirl anyways.
Question:
How do you use a POST method if you do not know the order in which to send data? (is there a standard or is every API different).
i have an API key and a secret API key to send for authorisation but still get access denied.
Is there anyway you can use code to request an order or something like you do when you pull a json to string?
WebRequest request = WebRequest.Create("https://www.coinspot.com.au/api/ro/balances");
request.Method = "POST";
request.Headers.Add("key", APIKEY);
request.ContentType = "application/json";
request.GetResponse(); //THIS IS WHERE IT ERRORS WITH AUTHENTICATION
sorry if its a scrub question but i think im looking at this the right way, i am also using .NET library json newtonsoft so any information on this would be fantastic!!
.NET Core interpretation of the somewhat dated yet functional CoinSpot node.js api client
var nonce = Utility.GetEpochTime();
var postData = new { nonce };
var jsonMessage = postData.ToJson();
var hmac = new HMACSHA512(Encoding.ASCII.GetBytes("CoinSpotSecret"));
var byteArray = Encoding.ASCII.GetBytes(jsonMessage);
using (var stream = new MemoryStream(byteArray)) {
var hash = hmac.ComputeHash(stream).Aggregate("", (s, e) => s + String.Format("{0:x2}", e), s => s);
var uri = new Uri("https://www.coinspot.com.au/api/ro/my/balances", UriKind.Absolute);
var content = new StringContent(
jsonMessage,
System.Text.Encoding.UTF8,
"application/json"
);
content.Headers.Add("sign", hash);
content.Headers.Add("key", "CoinSpotKey");
var response = await httpClient.PostAsync(uri, content);
if (response.IsSuccessStatusCode) {
return await response.Content.ReadAsStringAsync();
}
}
Related
I want to download data of this website into a json file but as I am quite new to coding with C# I cant manage to get the data. I want to get Data of https://discosweb.esoc.esa.int/api/objects the authorization via token works but I dont know how I can send a request so the server gives me a json back and I cant find a solution online. I cant give you a screenshot of the API because you have to be logged in to see it. Plz ask me for detailed information if you can help me. Thank you realy for trying.
The code I want to run is here.
class Program
{
static HttpClient client = new HttpClient();
static void Main(string[] args)
{
client.BaseAddress = new Uri("https://discosweb.esoc.esa.int");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/vnd.api+json"));
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("my_token");
var httpRequest = (HttpWebRequest)WebRequest.Create(client.BaseAddress);
var httpResponse = (HttpWebResponse)httpRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var streamReaderResult = streamReader.ReadToEnd();
}
Console.WriteLine("Status https://discosweb.esoc.esa.int : " + httpResponse.StatusCode);
}
}
Try this
var url = "https://discosweb.esoc.esa.int/api/objects";
var httpRequest = (HttpWebRequest)WebRequest.Create(url);
httpRequest.Method = "POST";
httpRequest.Headers["Authorization"] = "Basic XXXx";
httpRequest.ContentType = "";
httpRequest.Headers["Content-Length"] = "0";
var httpResponse = (HttpWebResponse)httpRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
}
Console.WriteLine(httpResponse.StatusCode);
Where XXXx is user:password in base64.
Here is a basic implementation for making that API call to get the JSON result. You will need to parse that JSON into something other than a string but I'll assume you can handle that part.
This uses System.Net.HttpClient which is the modern HTTP api provided by .NET. Its operations are async so hopefully your code is or can be written to properly await async operations.
//Someplace convenient, create a shared HttpClient to avoid
//creating and disposing for each request.
HttpClient client = new HttpClient();
string data = await GetObjects(client);
//Example implementation
public async Task<string> GetObjects(HttpClient client)
{
string url = "https://discosweb.esoc.esa.int/api/objects";
using (HttpRequestMessage msg = new HttpRequestMessage(HttpMethod.Get, url))
{
msg.Headers.Authorization =
new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", "your personal access token here");
using (var result = await client.SendAsync(msg))
{
string content = await result.Content.ReadAsStringAsync();
return content;
}
}
}
While I may be a month late, I've actually developed an SDK for this particular API.
So, if you use this SDK it's pretty simple to do what you want. You can essentially forget about handling anything HTTP related, my SDK abstracts all of that away.
For example, to fetch Sputnik's data (which has an ID of 1) you'd run.
HttpClient innerClient = new();
innerClient.BaseAddress = "https://discosweb.esoc.esa.int/api/"
innerClient.DefaultRequestHeaders.Authorization = new("bearer", yourApiKey);
DiscosClient client = new();
DiscosObject sputnik = await client.GetSingle<DiscosObject>("1");
If you're using ASP.NET, there's a set of DI extensions that can actually set it all up for you, so you can skip the first three lines.
If you do choose to use it, please let me know, as it would be nice knowing my SDK is getting some use. If you have any issues, please just reach out through the GitHub issues page and I'll try to help!
Currently to send a parameterized GET request to an API interface I am writing the following code:
api/master/city/filter?cityid=1&citycode='ny'
But I see that there is a limit on the URL length of 2,083 characters.
To avoid this I would like to send the parameters in json format in the content body for a GET request.
However, I see that none of the Get methods for the HttpClient allow for a content body to be sent. For the POST I could see there is a method within HttpClient named PostAsync that allows for a content body.
Is there a way to send parameters for a GET request not in the URL in order to avoid the URL length limit?
Please read the caveats at the end of this answer as to why HTTP GET requests with bodies are, in general, not advised.
If you are using .NET Core, the standard HttpClient can do this out-of-the-box. For example, to send a GET request with a JSON body:
HttpClient client = ...
...
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = new Uri("some url"),
Content = new StringContent("some json", Encoding.UTF8, MediaTypeNames.Application.Json /* or "application/json" in older versions */),
};
var response = await client.SendAsync(request).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
var responseBody = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
.NET Framework doesn't support this out-of-the-box (you will receive a ProtocolViolationException if you try the above code). Thankfully Microsoft has provided the System.Net.Http.WinHttpHandler package that does support the functionality - simply install and use it instead of the default HttpClientHandler when constructing your HttpClient instances:
var handler = new WinHttpHandler();
var client = new HttpClient(handler);
<rest of code as above>
Reference: https://github.com/dotnet/runtime/issues/25485#issuecomment-467261945
Caveats:
HTTP GET with a body is a somewhat unconventional construct that falls in a gray area of the HTTP specification - the end result is that many older pieces of software either cannot handle such a request at all, or will explicitly reject it because they believe it to be malformed. You need to make very sure that the endpoint you're trying to send such a request to does support it, or at best you will get an HTTP error code back; at worst the body will be silently discarded. This can lead to some head-scratching debugging!
Caching proxy servers, again particularly older ones, may cache GET requests based only on the URL because they don't expect a body to be present. This could either result in the least recent request being cached forever (which will break your software), or that the only request ever cached is the most recent one issued (which will prevent caching from working as intended). Again, this can be very painful to figure out.
I can't use .NET core and I don't want to install System.Net.Http.WinHttpHandler, which has a ton of dependencies.
I solved it by using reflection, to trick WebRequest that it is legal to send body with a GET request (which is according to latest RFC). What I do is to set ContentBodyNotAllowed to false for HTTP verb "GET".
var request = WebRequest.Create(requestUri);
request.ContentType = "application/json";
request.Method = "GET";
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write("<Json string here>");
}
var response = (HttpWebResponse)request.GetResponse();
Note, however, that the attribute ContentBodyNotAllowed belongs to a static field, so when its value changes, it remains in effect for the rest of the program. That's not a problem for my purposes.
I use WebRequest.
The value is in variable json.
var request = WebRequest.Create(requestUri);
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
request.ContentType = "application/json";
request.Method = "GET";
request.Headers.Add("Authorization", "Bearer " + Token);
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write(JsonConvert.SerializeObject(Entity));
}
var response = request.GetResponse();
var responseStream = response.GetResponseStream();
if (responseStream != null)
{
var myStreamReader = new StreamReader(responseStream, Encoding.Default);
var resultEntity= myStreamReader.ReadToEnd();
myStreamReader.ReadToEnd());
}
responseStream.Close();
response.Close();
After spending a lot of time I couldn't make neither HttpClient nor WebRequest work in my .Net Core project, apparently the server was not getting my data and it returned an error saying some specific data was not available in my request. At last only RestSharp worked in my case (the variable myData is a Dictionary<string,string> instance in the following code):
var client = new RestClient("some url");
var request = new RestRequest(Method.GET);
foreach (var d in myData)
request.AddParameter(d.Key, d.Value);
var result = (await client.ExecuteAsync(request)).Content;
similar to above answer but less code
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = targetUri,
Content = new StringContent(payload.Payload),
};
var response = await client.SendAsync(request).ConfigureAwait(false);
var responseInfo = await response.Content.ReadAsStringAsync();
I have an api
http://cbastest.cadvilpos.com/module/posmodule/customapi
with parameters
{
"action":4,
"device_token": "3e8ea119a90ee6d2",
"key":"9475962085b3a1b8c475d52.95782804",
"shop":1,
"language":1
}
This is working fine in postman. But when I try to connect from c# project its showing an error {"success":0,"error":"Missing the action parameter."}. Please give a working C# code to get the json result.
The code I tried:
var request = (HttpWebRequest)WebRequest.Create("http://cbastest.cadvilpos.com/module/posmodule/customapi");
var postData = "{ 'action':'4', 'device_token':'3e8ea119a90ee6d2','key':'9475962085b3a1b8c475d52.95782804','shop':'1','language':'1'}";
var data = Encoding.ASCII.GetBytes(postData);
request.Method = "POST";
request.ContentType = "application/json";
request.ContentLength = data.Length;
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
var response2 = (HttpWebResponse)request.GetResponse();
var responseString = new StreamReader(response2.GetResponseStream()).ReadToEnd();
You don't need to use a raw HttpWebRequest object to make an HTTP call. HttpClient was introduced in 2012 to allow easy asynchronous HTTP calls.
You could do something as simple as :
var content=new StringContent(postData,Encoding.UTF8, "application/json");
HttpResponseMessage response=await httpClient.PostAsync(url,content);
//Now process the response
if (response.IsSuccessCode)
{
var body=await response.Content.ReadAsStringAsync();
var responseDTO=JsonConvert.DeserializeObject<MyDTO>(body);
}
Instead of building a JSON string by hand you could use a strongly typed class or an anonymous object and serialize it to JSON with JSON.NET :
var data=new {
action=4,
device_token="3e8ea119a90ee6d2",
key = "9475962085b3a1b8c475d52.95782804",
shop=1,
language=1
};
var postData=JsonConvert.SerializeObject(data);
var content=new StringContent(postData,Encoding.UTF8, "application/json");
var response=await httpClient.PostAsync(url,content);
...
You can read a response body in one go as a string, using ReadAsStringAsync or you can get the response stream with ReadAsStreamAsync. You could copy the response data directly to another stream, eg a file or memory stream with HttpContent.CopyToAsync
Check Call a Web API from a .NET Client for more examples. Despite the title, the examples work to call any HTTP/REST API.
The Microsoft.AspNet.WebApi.Client package mentioned in that article is another thing that applies to any call, not just calls to ASP.NET Web API. The extension method PostAsJsonAsync for example, combines serializing and posting a request to a url. Using it, posting the action DTO could be reduced to a single line:
var data=new {
action=4,
device_token="3e8ea119a90ee6d2",
key = "9475962085b3a1b8c475d52.95782804",
shop=1,
language=1
};
var response=await httpClient.PostAsJsonAsync(url,data);
There is a button in Postman that will generate code for the currently defined request. The link is here:
And this is what the code looks like. You'll need to pull in RestSharp from Nuget
Currently to send a parameterized GET request to an API interface I am writing the following code:
api/master/city/filter?cityid=1&citycode='ny'
But I see that there is a limit on the URL length of 2,083 characters.
To avoid this I would like to send the parameters in json format in the content body for a GET request.
However, I see that none of the Get methods for the HttpClient allow for a content body to be sent. For the POST I could see there is a method within HttpClient named PostAsync that allows for a content body.
Is there a way to send parameters for a GET request not in the URL in order to avoid the URL length limit?
Please read the caveats at the end of this answer as to why HTTP GET requests with bodies are, in general, not advised.
If you are using .NET Core, the standard HttpClient can do this out-of-the-box. For example, to send a GET request with a JSON body:
HttpClient client = ...
...
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = new Uri("some url"),
Content = new StringContent("some json", Encoding.UTF8, MediaTypeNames.Application.Json /* or "application/json" in older versions */),
};
var response = await client.SendAsync(request).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
var responseBody = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
.NET Framework doesn't support this out-of-the-box (you will receive a ProtocolViolationException if you try the above code). Thankfully Microsoft has provided the System.Net.Http.WinHttpHandler package that does support the functionality - simply install and use it instead of the default HttpClientHandler when constructing your HttpClient instances:
var handler = new WinHttpHandler();
var client = new HttpClient(handler);
<rest of code as above>
Reference: https://github.com/dotnet/runtime/issues/25485#issuecomment-467261945
Caveats:
HTTP GET with a body is a somewhat unconventional construct that falls in a gray area of the HTTP specification - the end result is that many older pieces of software either cannot handle such a request at all, or will explicitly reject it because they believe it to be malformed. You need to make very sure that the endpoint you're trying to send such a request to does support it, or at best you will get an HTTP error code back; at worst the body will be silently discarded. This can lead to some head-scratching debugging!
Caching proxy servers, again particularly older ones, may cache GET requests based only on the URL because they don't expect a body to be present. This could either result in the least recent request being cached forever (which will break your software), or that the only request ever cached is the most recent one issued (which will prevent caching from working as intended). Again, this can be very painful to figure out.
I can't use .NET core and I don't want to install System.Net.Http.WinHttpHandler, which has a ton of dependencies.
I solved it by using reflection, to trick WebRequest that it is legal to send body with a GET request (which is according to latest RFC). What I do is to set ContentBodyNotAllowed to false for HTTP verb "GET".
var request = WebRequest.Create(requestUri);
request.ContentType = "application/json";
request.Method = "GET";
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write("<Json string here>");
}
var response = (HttpWebResponse)request.GetResponse();
Note, however, that the attribute ContentBodyNotAllowed belongs to a static field, so when its value changes, it remains in effect for the rest of the program. That's not a problem for my purposes.
I use WebRequest.
The value is in variable json.
var request = WebRequest.Create(requestUri);
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
request.ContentType = "application/json";
request.Method = "GET";
request.Headers.Add("Authorization", "Bearer " + Token);
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write(JsonConvert.SerializeObject(Entity));
}
var response = request.GetResponse();
var responseStream = response.GetResponseStream();
if (responseStream != null)
{
var myStreamReader = new StreamReader(responseStream, Encoding.Default);
var resultEntity= myStreamReader.ReadToEnd();
myStreamReader.ReadToEnd());
}
responseStream.Close();
response.Close();
After spending a lot of time I couldn't make neither HttpClient nor WebRequest work in my .Net Core project, apparently the server was not getting my data and it returned an error saying some specific data was not available in my request. At last only RestSharp worked in my case (the variable myData is a Dictionary<string,string> instance in the following code):
var client = new RestClient("some url");
var request = new RestRequest(Method.GET);
foreach (var d in myData)
request.AddParameter(d.Key, d.Value);
var result = (await client.ExecuteAsync(request)).Content;
similar to above answer but less code
var request = new HttpRequestMessage
{
Method = HttpMethod.Get,
RequestUri = targetUri,
Content = new StringContent(payload.Payload),
};
var response = await client.SendAsync(request).ConfigureAwait(false);
var responseInfo = await response.Content.ReadAsStringAsync();
I am beginner and creating winform application. In which i have to use API for Simple CRUD operation. My client had shared API with me and asked to send data in form of JSON.
API : http://blabla.com/blabla/api/login-valida
KEY : "HelloWorld"
Value : { "email": "user#gmail.com","password": "123456","time": "2015-09-22 10:15:20"}
Response : Login_id
How can i convert data to JSON, call API using POST method and get response?
EDIT
Somewhere on stackoverflow i found this solution
public static void POST(string url, string jsonContent)
{
url="blabla.com/api/blala" + url;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(baseURL);
request.Method = "POST";
System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
Byte[] byteArray = encoding.GetBytes(jsonContent);
request.ContentLength = byteArray.Length;
request.ContentType = #"application/json";
using (Stream dataStream = request.GetRequestStream())
{
dataStream.Write(byteArray, 0, byteArray.Length);
}
long length = 0;
try
{
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
length = response.ContentLength;
}
}
catch
{
throw;
}
}
//on my login button click
private void btnLogin_Click(object sender, EventArgs e)
{
CallAPI.POST("login-validate", "{ \"email\":" + txtUserName.Text + " ,\"password\":" + txtPassword.Text + ",\"time\": " + DateTime.Now.ToString("yyyy-MM-dd h:mm tt") + "}");
}
I got exception that says "The remote server returned an error: (404) Not Found."
You can take a look at the following docs tutorial:
Call a Web API From a .NET Client
But as an answer, here I will share a quick and short a step by step guide about how to call and consume web API in Windows forms:
Install Package - Install the Microsoft.AspNet.WebApi.Client NuGet package (Web API Client Libraries).
Open Tools menu → NuGet Package Manager → Package Manager Console → In the Package Manager Console window, type the following command:
Install-Package Microsoft.AspNet.WebApi.Client
You can install package by right click on project and choosing Manage NuGet Packages as well.
Set up HttpClient - Create an instance of HttpClient and set up its BaseAddress and DefaultRequestHeaders. For example:
// In the class
static HttpClient client = new HttpClient();
// Put the following code where you want to initialize the class
// It can be the static constructor or a one-time initializer
client.BaseAddress = new Uri("http://localhost:4354/api/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
Send Request - To send the requests, you can use the following methods of the HttpClient:
GET: GetAsync, GetStringAsync, GetByteArrayAsync, GetStreamAsync
POST: PostAsync, PostAsJsonAsync, PostAsXmlAsync
PUT: PutAsync, PutAsJsonAsync, PutAsXmlAsync
DELETE: DeleteAsync
Another HTTP method: Send
Note: To set the URL of the request for the methods, keep in mind, since you have specified the base URL when you defined the client, then here for these methods, just pass path, route values and query strings, for example:
// Assuming http://localhost:4354/api/ as BaseAddress
var response = await client.GetAsync("products");
or
// Assuming http://localhost:4354/api/ as BaseAddress
var product = new Product() { Name = "P1", Price = 100, Category = "C1" };
var response = await client.PostAsJsonAsync("products", product);
Get the Response
To get the response, if you have used methods like GetStringAsync, then you have the response as string and it's enough to parse the response. If the response is a Json content which you know, you can easily use JsonConvert class of Newtonsoft.Json package to parse it. For example:
// Assuming http://localhost:4354/api/ as BaseAddress
var response = await client.GetStringAsync("product");
var data = JsonConvert.DeserializeObject<List<Product>>(response);
this.productBindingSource.DataSource = data;
If you have used methods like GetAsync or PostAsJsonAsync and you have an HttpResponseMessage then you can use ReadAsAsync, ReadAsByteArrayAsync, ReadAsStreamAsync, `ReadAsStringAsync, for example:
// Assuming http://localhost:4354/api/ as BaseAddress
var response = await client.GetAsync("products");
var data = await response.Content.ReadAsAsync<IEnumerable<Product>>();
this.productBindingSource.DataSource = data;
Performance Tip
HttpClient is a type that is meant to be created once and then shared. So don't try to put it in a using block every time that you want to use it. Instead, create an instance of the class and share it through a static member. To read more about this, take a look at Improper Instantiation antipattern
Design Tip
Try to avoid mixing the Web API related code with your application logic. For example let's say you have a product Web API service. Then to use it, first define an IProductServieClient interface, then as an implementation put all the WEB API logic inside the ProductWebAPIClientService which you implement to contain codes to interact with WEB API. Your application should rely on IProductServieClient. (SOLID Principles, Dependency Inversion).
Just use the following library.
https://www.nuget.org/packages/RestSharp
GitHub Project: https://github.com/restsharp/RestSharp
Sample Code::
public Customer GetCustomerDetailsByCustomerId(int id)
{
var client = new RestClient("http://localhost:3000/Api/GetCustomerDetailsByCustomerId/" + id);
var request = new RestRequest(Method.GET);
request.AddHeader("X-Token-Key", "dsds-sdsdsds-swrwerfd-dfdfd");
IRestResponse response = client.Execute(request);
var content = response.Content; // raw content as string
dynamic json = JsonConvert.DeserializeObject(content);
JObject customerObjJson = json.CustomerObj;
var customerObj = customerObjJson.ToObject<Customer>();
return customerObj;
}
Use Json.Net to convert data into JSON
Use WebClient to POST data
Use This code:
var client = new HttpClient();
client.BaseAddress = new Uri("http://www.mywebsite.com");
var request = new HttpRequestMessage(HttpMethod.Post, "/path/to/post/to");
var keyValues = new List<KeyValuePair<string, string>>();
keyValues.Add(new KeyValuePair<string, string>("site", "http://www.google.com"));
keyValues.Add(new KeyValuePair<string, string>("content", "This is some content"));
request.Content = new FormUrlEncodedContent(keyValues);
var response = await client.SendAsync(request);
Here is another example using an online REST service (https://northwind.vercel.app) which allows interaction with Northwind API.
This example uses HttpClient and JsonConvert to get or post data. Here is a very quick example:
Install Newtonsoft.Json nuget package. And add the following using statements to your form:
using System.Net.Http;
using Newtonsoft.Json
Define an instance of the HttpClient, at class level:
private static HttpClient client = new HttpClient();
To send a GET request, for example getting list of all data:
var url = "https://northwind.vercel.app/api/categories";
var response = await client.GetAsync(url);
if (response.StatusCode == System.Net.HttpStatusCode.OK)
{
var content = await response.Content.ReadAsStringAsync();
var categories = JsonConvert.DeserializeObject<List<Category>>(content);
dataGridView1.DataSource = categories;
}
You can also use other overloads of Get, like GetStringAsync, GetStreamAsync, and etc. But GetAsync is a more generic method allowing you to get the status code as well.
To send a POST request, for example posting a new data:
var url = "https://northwind.vercel.app/api/categories";
var data = new Category() { Name = "Lorem", Description = "Ipsum" };
var jsonData = Newtonsoft.Json.JsonConvert.SerializeObject(data);
var requestContent = new StringContent(jsonData, Encoding.Unicode, "application/json");
var response = await client.PostAsync(url, requestContent);
if (response.StatusCode == System.Net.HttpStatusCode.Created)
{
var content = await response.Content.ReadAsStringAsync();
var createdCategory = JsonConvert.DeserializeObject<Category>(content);
MessageBox.Show(createdCategory.Id.ToString())
}
To learn more and see some best practices or see an example without JsonConvert, see my other post.