Consume Web API Using WebClient In C#

We can Get and Post data from a Web API using Web client. Web client provides common methods for sending and receiving data from Server. Here, I have not used any authentication and authorization mechanism. This is simple - it's just for sending and receiving data from API.

First, you have to assign the API Endpoint on a variable. Here, I have created one static class to assign the API Endpoint.

public static class StaticItems
{
public static string EndPoint = "http://localhost:8088/api/";
}

Here, I have also created a class of name City.

public class CityInfo
{
public int CityID { get; set; }
public int CountryID { get; set; }
public int StateID { get; set; }
public string Name { get; set; }
public decimal Latitude { get; set; }
public decimal Longitude { get; set; }
}

Receiving Data from API

This function retrieves data from API. Here, this function returns the list of cities. The data received from the API is in JSON format so I have deserialized that JSON data to an Object List. The Keyword DownloadString is used for retrieving data from Server.

public List < CityInfo > CityGet() {
try {
using(WebClient webClient = new WebClient()) {
webClient.BaseAddress = StaticItems.EndPoint;
var json = webClient.DownloadString("City/CityGetForDDL");
var list = JsonConvert.DeserializeObject < List < CityInfo >> (json);
return list.ToList();
}
} catch (WebException ex) {
throw ex;
}
}

Sending Data to Api

This function sends data to the API. Here, I have converted the object of the city into JSON.

The keyword UploadString is used for sending data to the Server.

public ReturnMessageInfo CitySave(CityInfo city) {
ReturnMessageInfo result = new ReturnMessageInfo();
try {
using(WebClient webClient = new WebClient()) {
webClient.BaseAddress = StaticItems.EndPoint;
var url = "City/CityAddUpdate";
webClient.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");
webClient.Headers[HttpRequestHeader.ContentType] = "application/json";
string data = JsonConvert.SerializeObject(city);
var response = webClient.UploadString(url, data);
result = JsonConvert.DeserializeObject < ReturnMessageInfo > (response);
return result;
}
} catch (Exception ex) {
throw ex;
}
}

Conclusion

Web client is easy to use for consuming the Web API. You can also use httpClient instead of WebClient. I hope you learned a little more about Web client and how a Web Client is used for sending and receiving data from Web API in C#. Let me know your queries in the comments section.

6 Comments

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Abanoub haliem5y ago
I have an exception " The underlying connection was closed: An unexpected error occurred on a send ."
Michael Brown5y ago
Every time I send to the server, the data is null????
amit6y ago
When i m trying to access web api with the help of httpclient, i m getting following error... The type or namespace name 'HttpClient' could not be found (are you missing a using directive or an assembly reference?)
- Dean Potter5y ago
  You add using system.net.http to import the namespace.
Pankajkumar Patel7y ago
Good article
- Bhuban Magar7y ago
  Thnk you @Pankaj Patel