Xamarin.Forms - Bing Web Search Using Cognitive Service

In this blog post, you will learn how to Search web pages using Cognitive Service in Xamarin forms.

Introduction

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 Web Search

1. Bing Web Search API is a RESTful service that provides an experience similar to Bing by returning search results that Bing determines are relevant to a user's questions. Search results are easily configured to include web pages, images, videos, news, translations, and more. 
2. Bing Web Search API is easy to call from any programming language that can make HTTP requests and parse JSON responses 

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 have more option in the opening window. Clone or checkout code from any repository or, open project or solution for your computer.
Now you can 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 in your preferred Location for projects and click Create.

Now, Select the Blank App and target Platform both 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 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="imgEmail" HeightRequest="100" Source="cognitiveservice.png" ></Image>
	<Label Margin="0,0,0,10" Text="Bing Web 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="listWebpage">
	</ListView>
	</StackLayout>
	</StackLayout>
	</StackLayout>
	</StackLayout>
	</ContentPage>

view raw MainPage.xaml hosted with ❤ by GitHub

Click the play button to try it out.

NuGet Packages

Now, add the following NuGet Packages.

1. 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

	namespace XamarinCognitive
	{
	public class ResponseModel
	{
	public string _type { get; set; }
	public QueryContext queryContext { get; set; }
	public WebPages webPages { get; set; }
	public Entities entities { get; set; }
	public RelatedSearches relatedSearches { get; set; }
	public Videos videos { get; set; }
	public RankingResponse rankingResponse { get; set; }
	}
	public class QueryContext
	{
	public string originalQuery { get; set; }
	}
	public class About
	{
	public string name { get; set; }
	}
	public class DeepLink
	{
	public string name { get; set; }
	public string url { get; set; }
	public string snippet { get; set; }
	}
	public class License
	{
	public string name { get; set; }
	public string url { get; set; }
	}
	public class SnippetAttribution
	{
	public License license { get; set; }
	public string licenseNotice { get; set; }
	}
	public class Item
	{
	public string _type { get; set; }
	public string text { get; set; }
	public string url { get; set; }
	}
	public class ListItem
	{
	public List<Item> items { get; set; }
	}
	public class ListData
	{
	public List<ListItem> listItems { get; set; }
	}
	public class Section
	{
	public string _type { get; set; }
	public string name { get; set; }
	public string siteName { get; set; }
	public string description { get; set; }
	public List<ListData> listData { get; set; }
	}
	public class RichCaption
	{
	public string _type { get; set; }
	public List<Section> sections { get; set; }
	}
	public class SearchTag
	{
	public string name { get; set; }
	public string content { get; set; }
	}
	public class Value
	{
	public string id { get; set; }
	public string name { get; set; }
	public string url { get; set; }
	public List<About> about { get; set; }
	public bool isFamilyFriendly { get; set; }
	public string displayUrl { get; set; }
	public string snippet { get; set; }
	public List<DeepLink> deepLinks { get; set; }
	public DateTime dateLastCrawled { get; set; }
	public string language { get; set; }
	public bool isNavigational { get; set; }
	public SnippetAttribution snippetAttribution { get; set; }
	public RichCaption richCaption { get; set; }
	public List<SearchTag> searchTags { get; set; }
	}
	public class WebPages
	{
	public string webSearchUrl { get; set; }
	public int totalEstimatedMatches { get; set; }
	public List<Value> value { get; set; }
	}
	public class License2
	{
	public string name { get; set; }
	public string url { get; set; }
	}
	public class ContractualRule
	{
	public string _type { get; set; }
	public string targetPropertyName { get; set; }
	public bool mustBeCloseToContent { get; set; }
	public License2 license { get; set; }
	public string licenseNotice { get; set; }
	public string text { get; set; }
	public string url { get; set; }
	}
	public class Provider
	{
	public string _type { get; set; }
	public string url { get; set; }
	}
	public class Image
	{
	public string name { get; set; }
	public string thumbnailUrl { get; set; }
	public List<Provider> provider { get; set; }
	public string hostPageUrl { get; set; }
	public int width { get; set; }
	public int height { get; set; }
	public int sourceWidth { get; set; }
	public int sourceHeight { get; set; }
	}
	public class EntityPresentationInfo
	{
	public string entityScenario { get; set; }
	public List<string> entityTypeHints { get; set; }
	public string entityTypeDisplayHint { get; set; }
	}
	public class Value2
	{
	public string id { get; set; }
	public List<ContractualRule> contractualRules { get; set; }
	public string webSearchUrl { get; set; }
	public string name { get; set; }
	public string url { get; set; }
	public Image image { get; set; }
	public string description { get; set; }
	public EntityPresentationInfo entityPresentationInfo { get; set; }
	public string bingId { get; set; }
	}
	public class Entities
	{
	public List<Value2> value { get; set; }
	}
	public class Value3
	{
	public string text { get; set; }
	public string displayText { get; set; }
	public string webSearchUrl { get; set; }
	}
	public class RelatedSearches
	{
	public string id { get; set; }
	public List<Value3> value { get; set; }
	}
	public class Publisher
	{
	public string name { get; set; }
	}
	public class Thumbnail
	{
	public int width { get; set; }
	public int height { get; set; }
	}
	public class Value4
	{
	public string webSearchUrl { get; set; }
	public string name { get; set; }
	public string description { get; set; }
	public string thumbnailUrl { get; set; }
	public DateTime datePublished { get; set; }
	public List<Publisher> publisher { get; set; }
	public bool isAccessibleForFree { get; set; }
	public string contentUrl { get; set; }
	public string hostPageUrl { get; set; }
	public string encodingFormat { get; set; }
	public string hostPageDisplayUrl { get; set; }
	public int width { get; set; }
	public int height { get; set; }
	public string duration { get; set; }
	public string motionThumbnailUrl { get; set; }
	public string embedHtml { get; set; }
	public bool allowHttpsEmbed { get; set; }
	public int viewCount { get; set; }
	public Thumbnail thumbnail { get; set; }
	public bool allowMobileEmbed { get; set; }
	public bool isSuperfresh { get; set; }
	}
	public class Videos
	{
	public string id { get; set; }
	public string readLink { get; set; }
	public string webSearchUrl { get; set; }
	public bool isFamilyFriendly { get; set; }
	public List<Value4> value { get; set; }
	public string scenario { get; set; }
	}
	public class Value5
	{
	public string id { get; set; }
	}
	public class Item2
	{
	public string answerType { get; set; }
	public int resultIndex { get; set; }
	public Value5 value { get; set; }
	}
	public class Mainline
	{
	public List<Item2> items { get; set; }
	}
	public class Value6
	{
	public string id { get; set; }
	}
	public class Item3
	{
	public string answerType { get; set; }
	public int? resultIndex { get; set; }
	public Value6 value { get; set; }
	}
	public class Sidebar
	{
	public List<Item3> items { get; set; }
	}
	public class RankingResponse
	{
	public Mainline mainline { get; set; }
	public Sidebar sidebar { get; set; }
	}
	}

view raw ResponseModel.cs hosted with ❤ by GitHub

Bing Web Search In this step, write the following code for Bing Web Search. MainPage.xaml.cs

	using System.IO;
	using System.Linq;
	using System.Net;
	using System.Text;
	using System.Threading.Tasks;
	using Xamarin.Forms;
	using Newtonsoft.Json;
	namespace XamarinCognitive
	{
	public partial class MainPage : ContentPage
	{
	public static string APIKey = "a30148ca5fc*********49b554fc4f683";
	public static string baseURl = "https://api.cognitive.microsoft.com/bing/v7.0/search";
	struct SearchResult
	{
	public String jsonResult;
	public Dictionary<String, String> relevantHeaders;
	}
	List<string> webResults = new List<string>();
	public MainPage()
	{
	InitializeComponent();
	}
	private void BtnSearch_Clicked(object sender, EventArgs e)
	{
	SearchResult bingResult=BingWebSearch(txtSearch.Text);
	var res = JsonConvert.DeserializeObject<ResponseModel>(bingResult.jsonResult);
	for(int i=0;i<res.webPages.value.Count;i++)
	{
	webResults.Add(res.webPages.value[i].name);
	}
	listWebpage.ItemsSource = webResults;
	}
	//Bing Web Search
	static SearchResult BingWebSearch(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()
	{
	jsonResult = json,
	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;
	}
	}
	}

view raw MainPage.xaml.cs hosted with ❤ by GitHub

Click the Play button to try it out. Android

UWP

I hope you have understood how to Search web pages using Cognitive Service Bing Search API in Xamarin.Forms. Thanks for reading. Please share comments and feedback. Happy Coding 😃