Xamarin.Forms - Bing News Search Using Cognitive Service

Introduction

Before starting, you can go through the following URL for an overview of Bing Web Search.

Xamarin.Forms code runs on multiple platforms - each of which has its own filesystem. This means that reading and writing files is most easily done using the native file APIs on each platform. Alternatively, embedded resources are a simpler solution to distribute data files with an app.

Cognitive Services

Xamarin and Cognitive Services together can infuse your apps, websites, and bots with intelligent algorithms to see, hear, speak, understand and interpret your user needs through natural methods of communication. Also, they help you transform your business with AI today.

Use AI to solve business problems

Vision
Speech
Knowledge
Search
Language

Bing News Search API

Bing News Search API provides an experience similar to Bing News.
Bing News Search API lets you send a search query to Bing and get back a list of relevant News from the Bing News Search API.

Prerequisites

Visual Studio 2017 or Later(Windows or Mac)
Bing Search API Key

Setting up a Xamarin.Forms Project

Start by creating a new Xamarin.Forms project. You’ll learn more by going through the steps yourself.

Visual Studio 2019 has more options in the opening window. Clone or check out the code from any repository or, open a project or solution for your computer.

Now, you need to click "Create a new project".

Now, filter by Project Type: Mobile

Choose the Mobile App (Xamarin. forms) project under C# and Mobile.

Name your app. You probably want your project and solution to use the same name as your app. Put it on your preferred location for projects and click "Create".

Now, select the blank app and target platforms - Android, iOS and Windows (UWP).

Subsequently, go to the solution. In there, you get all the files and sources of your project (.NET Standard). Now, select XAML page and double-click to open the MainPage.Xaml page.

You now have a basic Xamarin.Forms app. Click the Play button to try it out.

Get Bing Search API Key

In this step, get Bing Search API Key. Go to the following link.

https://azure.microsoft.com/en-in/services/cognitive-services/

Click "Try Cognitive Services for free".

Now, you can choose Bing Search APIs under Search APIs. Afterward, click "Get API Key".

Read the terms, and select your country/region. Afterward, click "Next".

Now, log in using your preferred account.

Now, the API key is activated. You can use it now.

Note

The trial key is available only for 7 days.

Setting up the User Interface

Go to MainPage.Xaml and write the following code.

MainPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:XamarinCognitive"
x:Class="XamarinCognitive.MainPage">
<StackLayout>
<StackLayout>
<StackLayout HorizontalOptions="Center" VerticalOptions="Start">
<Image x:Name="imgBanner" Source="banner.png" ></Image>
<Image Margin="0,0,0,10" x:Name="imgCognitive" HeightRequest="100" Source="cognitiveservice.png" ></Image>
<Label Margin="0,0,0,10" Text="Bing News Search" FontAttributes="Bold" FontSize="Large" TextColor="Gray" HorizontalTextAlignment="Center" ></Label>
<Entry x:Name="txtSearch" Placeholder="Type here.."></Entry>
<Button x:Name="btnSearch" WidthRequest="50" Text="Search" Clicked="BtnSearch_Clicked" />
<StackLayout HorizontalOptions="CenterAndExpand" Margin="10,0,0,10">
<ListView x:Name="listNews">
</ListView>
</StackLayout>
</StackLayout>
</StackLayout>
</StackLayout>
</ContentPage>

Click the play button to try it out.

NuGet Packages

Now, add the following NuGet Packages.

Newtonsoft.Json

Add Newtonsoft.Json NuGet

Go to Solution Explorer and select your solution. Right-click and select "Manage NuGet Packages for Solution". Search "Newtonsoft.Json" and add Package. Remember to install it for each project (.NET Standard, Android, iO, and UWP).

Create a Model

In this step, you can create a model for Deserializing your response.

ResponseModel.cs

using System;
using System.Collections.Generic;
using System.Text;
namespace XamarinCognitive
{
public class ResponseModel
{
public string _type { get; set; }
public string readLink { get; set; }
public QueryContext queryContext { get; set; }
public int totalEstimatedMatches { get; set; }
public List<Sort> sort { get; set; }
public List<Value> value { get; set; }
}
public class QueryContext
{
public string originalQuery { get; set; }
public bool adultIntent { get; set; }
}
public class Sort
{
public string name { get; set; }
public string id { get; set; }
public bool isSelected { get; set; }
public string url { get; set; }
}
public class Thumbnail
{
public string contentUrl { get; set; }
public int width { get; set; }
public int height { get; set; }
}
public class Image
{
public Thumbnail thumbnail { get; set; }
}
public class About
{
public string readLink { get; set; }
public string name { get; set; }
}
public class Provider
{
public string _type { get; set; }
public string name { get; set; }
}
public class Value
{
public string name { get; set; }
public string url { get; set; }
public Image image { get; set; }
public string description { get; set; }
public List<About> about { get; set; }
public List<Provider> provider { get; set; }
public DateTime datePublished { get; set; }
public string category { get; set; }
}
}

Bing Image Search

In this step, write the following code for Bing News Search.

MainPage.xaml.cs

using Xamarin.Forms;
using Newtonsoft.Json;
namespace XamarinCognitive
{
public partial class MainPage : ContentPage
{
public static string APIKey = "d9196daefdd64a******849a759ba8861";
public static string baseURl = "https://api.cognitive.microsoft.com/bing/v7.0/news/search";
struct SearchResult
{
public String jsonResult;
public Dictionary<String, String> relevantHeaders;
}
List<string> newsList = new List<string>();
public MainPage()
{
InitializeComponent();
}
private void BtnSearch_Clicked(object sender, EventArgs e)
{
SearchResult bingResult = BingNewsSearch(txtSearch.Text);
var res = JsonConvert.DeserializeObject<ResponseModel>(bingResult.jsonResult);
for (int i = 0; i < res.value.Count; i++)
{
newsList.Add(res.value[i].name);
}
listNews.ItemsSource = newsList;
}
//Bing News Search
static SearchResult BingNewsSearch(string searchQuery)
{
var uriQuery = baseURl + "?q=" + Uri.EscapeDataString(searchQuery);
WebRequest request = HttpWebRequest.Create(uriQuery);
request.Headers["Ocp-Apim-Subscription-Key"] = APIKey;
HttpWebResponse response = (HttpWebResponse)request.GetResponseAsync().Result;
string json = new StreamReader(response.GetResponseStream()).ReadToEnd();
var searchResult = new SearchResult();
searchResult.jsonResult = json;
searchResult.relevantHeaders = new Dictionary<String, String>();
foreach (String header in response.Headers)
{
if (header.StartsWith("BingAPIs-") || header.StartsWith("X-MSEdge-"))
searchResult.relevantHeaders[header] = response.Headers[header];
}
return searchResult;
}
}
}

Click the Play button to try it out.

I hope you have understood how to Search news using Bing Search API using Cognitive Service Bing Search API in Xamarin.Forms.

Thanks for reading. Please share comments and feedback. Happy Coding :)