Amit Kumar

Here i am going to explain, how to create generic web api client request, 1. It will helps you to manage all HTTP request from single class. 2. It will helps you to reduce your number of duplicate code as well. (No more repeat code for HTTP client). Use NuGet Package Manager to install the Web API Client Libraries package. From the Tools menu, select NuGet Package Manager > Package Manager Console. In the Package Manager Console (PMC), type the following command: Install-Package Microsoft.AspNet.WebApi.Client Following is the sample code for Generic HTTP request: using System; using System.Net.Http; using System.Net.Http.Headers; using System.Text; using System.Threading.Tasks; namespace ApiRequestSample {     public class GenericHttpRequest     {         protected static string HeaderName { get { return "AuthenticationToken"; } }         protected static string HeaderValue { get { return "XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXX

Basic authentication sends additional information in every HTTP request, using basic authentication, we would pass the user’s credentials or the authentication token in the header of the HTTP request. That header information will be checked at the server side. If the information sent in header is correct then it will give 200 OK as response, if not then it will give 401 unauthorised access as response. Following the code sample of HTTP Basic Authentication: Step 1: Create Helper Class for Basic Authentication using System.Linq; using System.Net; using System.Net.Http; using System.Threading; using System.Threading.Tasks; using System.Web;   namespace ApiServer.Helper {     /// <summary>     /// Purpose: This class is used for authencation of HTTP request by end user.     /// </summary>     public class BasicAuthentication : DelegatingHandler     {         protected async override Task<HttpResponseMessage> SendAsync(HttpRequestMe

In xamarin.forms, their is no event available to check listview scroll state. So, in that case, we have to customize the Listview control in xamarin.forms. Following is the sample code to detect scroll state of listview: Portable Library:  In a portable library project, add class “CustomListview.cs”  public class CustomListview : ListView {     public CustomListview() { }     public CustomListview(ListViewCachingStrategy cachingStrategy) : base(cachingStrategy) { }     public event EventHandler<ScrollStateChangedEventArgs> ScrollStateChanged;     public static void OnScrollStateChanged(object sender, ScrollStateChangedEventArgs e)     {         var customListview = (CustomListview)sender;         customListview.ScrollStateChanged?.Invoke(customListview, e);     }     public event EventHandler<ItemTappedIOSEventArgs> ItemTappedIOS;     public static void OnItemTappedIOS(object sender, ItemTappedIOSEventArgs e)     {         var custom

In this post, i am going to explain how to send mutipart/form-data from client side. A HTTP multipart request helps to send files/images and data over to a HTTP server. It is a very common approach used by browsers and any other HTTP clients to upload files to the server. using System; using System.Linq; using System.Net.Http; using Xamarin.Forms; namespace ClientApi {     public partial class MainPage : ContentPage     {         public MainPage()         {             InitializeComponent();         }         /// <summary>         /// Purpose: Post multipart data i.e. image or file         /// </summary>         protected async void SaveAttachment(byte[] attachment, string fileName, string attachmentType, string orgFileName)         {             try             {                 using (var httpClient = new HttpClient())                 {                     MultipartFormDataContent form = new MultipartFormDataContent();                    

In this post, i am going to explain how to upload and save image or file using Asp.Net WebApi. Key Notes regarding the code: 1. HttpResponseMessage : A HttpResponseMessage enables us to work with the HTTP convention. In straightforward words a HttpResponseMessage is a method for restoring a message/information from your activity. 2. EXIF Orientation : It changes the orientation of the picture and image captured by mobile phone. To handle this problem, refer to the below snipets. using System; using System.Drawing; using System.Drawing.Imaging; using System.IO; using System.Net; using System.Net.Http; using System.Web; using System.Web.Http; namespace WebApplication1.Controllers {     public class FileController : ApiController     {         public enum MessageType         {             Image = 0,             File = 1         }         /// <summary>         /// Purpose: Upload file or image         /// </summary>         [HttpPost]