How to call a .NET web service from android?

Calling a .NET Web Service from Android

This article will guide you on how to consume a .NET web service from an Android application. We will cover the essential steps and concepts required to establish communication between your Android app and the .NET web service.

Prerequisites

• Android Studio
• A .NET Web Service
• Basic understanding of Android development
• Knowledge of XML and JSON

Creating a .NET Web Service

First, you need a .NET web service to interact with. Let’s create a simple web service using ASP.NET Web API. You can create this service using Visual Studio or a similar IDE.

Sample .NET Web Service

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace MyWebService
{
    public class MyController : ApiController
    {
        // Sample endpoint to return a string
        [HttpGet]
        public string GetGreeting()
        {
            return "Hello from .NET Web Service!";
        }
    }
}

In this example, we created a MyController with a GetGreeting method. This method returns a simple string “Hello from .NET Web Service!”.

Calling the .NET Web Service from Android

Now, let’s consume this .NET web service from an Android application. We’ll use the HttpURLConnection class to make HTTP requests to the web service.

Setting up the Project

• Create a new Android project in Android Studio.
• Add internet permission in your AndroidManifest.xml file:

Making the HTTP Request

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import android.os.AsyncTask;
import android.util.Log;

public class MyAsyncTask extends AsyncTask<Void, Void, String> {

    @Override
    protected String doInBackground(Void... params) {
        try {
            // Replace with your actual web service URL
            URL url = new URL("http://your-server-address/MyWebService/api/MyController/GetGreeting");
            URLConnection conn = url.openConnection();
            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String inputLine;
            StringBuffer response = new StringBuffer();
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();
            return response.toString();
        } catch (Exception e) {
            Log.e("Error", "Error in making HTTP request: " + e.getMessage());
        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        // Handle the response here
        Log.d("Response", result);
    }
}

In this code, we define an AsyncTask to perform the HTTP request. This asynchronous task allows us to handle the request and process the response on a separate thread, avoiding blocking the UI thread.

Using the Response

Once you have the response string from the web service, you can parse it using libraries like Gson or Jackson. The response can be in JSON, XML, or another format based on your web service’s configuration.

Alternative Methods

While HttpURLConnection is a basic method, other more convenient libraries exist for consuming web services. These libraries can handle serialization, error handling, and other common tasks, simplifying your code:

Conclusion

By following these steps, you can successfully communicate between your Android app and a .NET web service. This allows you to leverage the power of .NET to build robust backend logic and provide data to your mobile application. Remember to choose the appropriate libraries and handle network operations effectively for a seamless user experience.