Quickstart: Search for entities and local businesses using C# and Bing Entity Search API
Use this quickstart to make your first call to Bing Entity Search API. This C# console application sends a search request to Bing and parses the response. Since it's a console application, it displays a text-based version of the response for illustrative purposes only. The source code for this sample is available on GitHub.
Grab your favorite .NET editor, JSON library, and Create Bing Search Service resource for Bing Entity Search and let's get started.
Create a project and declare dependencies
Create a new project and declare the code's dependencies. This example uses Newtonsoft to parse the JSON response. Use Newtonsoft's NuGet package to install its libraries.
using System;
using System.Net.Http.Headers;
using System.Net.Http;
using System.Threading.Tasks;
using System.Linq;
using System.Collections.Generic;
using Newtonsoft.Json;
Declare a namespace and class for your program
Add a namespace and class. This example uses EntitySearchQuickstart for the namespace and Program for the class.
namespace EntitySearchQuickstart
{
class Program
{
// The code in the following sections goes here.
}
}
Define variables
Add a few variables to the Program class. For simplicity, this example hardcodes the subscription key, but make sure you're pulling it from secured storage instead.
// In production, make sure you're pulling the subscription key from secured storage.
private static string _subscriptionKey = "<your key goes here>";
private static string _baseUri = "https://api.bing.microsoft.com/v7.0/entities";
// The user's search string.
private static string searchString = "bill gates";
// Bing uses the X-MSEdge-ClientID header to provide users with consistent
// behavior across Bing API calls. See the reference documentation
// for usage.
private static string _clientIdHeader = null;
Here are all the query parameters you can add to the base URI. The q parameter is required and you should always include the mkt parameter too. The rest are optional. For information about these parameters, see Query parameters.
private const string QUERY_PARAMETER = "?q="; // Required
private const string MKT_PARAMETER = "&mkt="; // Strongly suggested
private const string RESPONSE_FILTER_PARAMETER = "&responseFilter=";
private const string SAFE_SEARCH_PARAMETER = "&safeSearch=";
Declare the Main method
Our Main() method is pretty simple since we're going to implement the HTTP requests asynchronously.
static void Main()
{
RunAsync().Wait();
}
Where all the work happens
The RunAsync method is where all the work happens. It builds the query string that's appended to the base URI, waits for the asynchronous HTTP request to return, deserializes the response, and either prints the search results or an error message.
This example uses dictionaries instead of objects to access the response data.
static async Task RunAsync()
{
try
{
// Remember to encode query parameters like q, responseFilters, etc.
var queryString = QUERY_PARAMETER + Uri.EscapeDataString(searchString);
queryString += MKT_PARAMETER + "en-us";
HttpResponseMessage response = await MakeRequestAsync(queryString);
_clientIdHeader = response.Headers.GetValues("X-MSEdge-ClientID").FirstOrDefault();
// This example uses dictionaries instead of objects to access the response data.
var contentString = await response.Content.ReadAsStringAsync();
Dictionary<string, object> searchResponse = JsonConvert.DeserializeObject<Dictionary<string, object>>(contentString);
if (response.IsSuccessStatusCode)
{
PrintResponse(searchResponse);
}
else
{
PrintErrors(response.Headers, searchResponse);
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
Console.WriteLine("\nPress ENTER to exit...");
Console.ReadLine();
}
The HTTP call
Here's the HTTP request. It's your basic HTTP GET request. Use whatever HTTP client works for you.
// Makes the request to the Entity Search endpoint.
static async Task<HttpResponseMessage> MakeRequestAsync(string queryString)
{
var client = new HttpClient();
// Request headers. The subscription key is the only required header but you should
// include User-Agent (especially for mobile), X-MSEdge-ClientID, X-Search-Location
// and X-MSEdge-ClientIP (especially for local aware queries).
client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", _subscriptionKey);
return (await client.GetAsync(_baseUri + queryString));
}
That's all the more there is to sending a search request and getting back search results. To see what all the answers look like in the JSON response, see Handling the entity search response.
The rest of the sections walk you through one way of parsing the JSON response and displaying the search results. Be sure to read the use and display requirements to make sure you comply with all display requirements.
Using ranking to display the search results
If the request succeeds, the code calls the PrintResponse method to print the search results in the console window.
The example uses the RankingResponse answer to display the search results. The ranking determines which answers to display in the pole, mainline, and sidebar sections of the search results page. For information about using the RankingResponse answer, see Use ranking to display search results.
// Prints the JSON response data for pole, mainline, and sidebar.
static void PrintResponse(Dictionary<string, object> response)
{
Console.WriteLine("The response contains the following answers:\n");
var ranking = response["rankingResponse"] as Newtonsoft.Json.Linq.JToken;
Newtonsoft.Json.Linq.JToken position;
if ((position = ranking["pole"]) != null)
{
Console.WriteLine("Pole Position:\n");
DisplayAnswersByRank(position["items"], response);
}
if ((position = ranking["mainline"]) != null)
{
Console.WriteLine("Mainline Position:\n");
DisplayAnswersByRank(position["items"], response);
}
if ((position = ranking["sidebar"]) != null)
{
Console.WriteLine("Sidebar Position:\n");
DisplayAnswersByRank(position["items"], response);
}
}
Display all results for an answer or a single result
Each item in the ranking tells you whether to display all results from the answer together or to display a single result from the answer.
If the item includes the resultIndex field, use the index value to display that single result from the answer. But if the item doesn't include resultIndex, you display all results from the answer.
// Displays each result based on ranking. Ranking contains the results for
// the pole, mainline, or sidebar section of the search results.
static void DisplayAnswersByRank(Newtonsoft.Json.Linq.JToken items, Dictionary<string, object> response)
{
foreach (Newtonsoft.Json.Linq.JToken item in items)
{
var answerType = (string)item["answerType"];
Newtonsoft.Json.Linq.JToken index = -1;
// If the ranking item doesn't include an index of the result to
// display, then display all the results for that answer.
if ("Entities" == answerType)
{
if ((index = item["resultIndex"]) == null)
{
DisplayAllEntities(((Newtonsoft.Json.Linq.JToken)response["entities"])["value"]);
}
else
{
DisplayEntity(((Newtonsoft.Json.Linq.JToken)response["entities"])["value"].ElementAt((int)index));
}
}
else if ("Places" == answerType)
{
if ((index = item["resultIndex"]) == null)
{
DisplayAllPlaces(((Newtonsoft.Json.Linq.JToken)response["places"])["value"]);
}
else
{
DisplayPlace(((Newtonsoft.Json.Linq.JToken)response["places"])["value"].ElementAt((int)index));
}
}
else
{
Console.WriteLine("\nUnknown answer type: {0}\n", answerType);
}
}
}
Display answer results
This example accesses a few of the fields from each type of answer result and applies any contractual rules. You will likely use data from more of the fields than are shown in this example. For information about the fields that each answer result may include, see Response objects.
// Displays all entities in the Entities answer.
static void DisplayAllEntities(Newtonsoft.Json.Linq.JToken entities)
{
foreach (Newtonsoft.Json.Linq.JToken entity in entities)
{
DisplayEntity(entity);
}
}
// Displays a single entity.
static void DisplayEntity(Newtonsoft.Json.Linq.JToken entity)
{
string rule = null;
// Entities require attribution. Gets the list of attributions to apply.
Dictionary<string, string> rulesByField = null;
rulesByField = GetRulesByField(entity["contractualRules"]);
Console.WriteLine("\tEntity\n");
Console.WriteLine("\t\tName: " + entity["name"]);
if (entity["image"] != null)
{
Console.WriteLine("\t\tImage: " + entity["image"]["thumbnailUrl"]);
if (rulesByField.TryGetValue("image", out rule))
{
Console.WriteLine("\t\t\tImage from: " + rule);
}
}
if (entity["description"] != null)
{
Console.WriteLine("\t\tDescription: " + entity["description"]);
if (rulesByField.TryGetValue("description", out rule))
{
Console.WriteLine("\t\t\tData from: " + rulesByField["description"]);
}
}
else
{
// See if presentation info can shed light on what this entity is.
var hintCount = entity["entityPresentationInfo"]["entityTypeHints"].Count();
Console.WriteLine("\t\tEntity hint: " + entity["entityPresentationInfo"]["entityTypeHints"][hintCount - 1]);
}
Console.WriteLine();
}
// Displays all places in the Places answer.
static void DisplayAllPlaces(Newtonsoft.Json.Linq.JToken places)
{
foreach (Newtonsoft.Json.Linq.JToken place in places)
{
DisplayPlace(place);
}
}
// Displays a single place.
static void DisplayPlace(Newtonsoft.Json.Linq.JToken place)
{
Console.WriteLine("\tPlace\n");
Console.WriteLine("\t\tName: " + place["name"]);
Console.WriteLine("\t\tPhone: " + place["telephone"]);
Console.WriteLine("\t\tWebsite: " + place["url"]);
Console.WriteLine();
}
Handling contractual rules
You need to check each result to see if it includes one or more contractual rules. Some rules apply to the result as a whole and others apply to a specific field. If the rule applies to a specific field, it includes the targetPropertyName field, which contains the name of the target field.
This example, builds a dictionary of the rules that the calling method accesses when it displays the result. If the rule applies to the result as a whole, the key is global. Otherwise, the key is the name of the field that the rule targets.
// Checks if the result includes contractual rules and builds a dictionary of
// the rules.
static Dictionary<string, string> GetRulesByField(Newtonsoft.Json.Linq.JToken contractualRules)
{
if (null == contractualRules)
{
return null;
}
var rules = new Dictionary<string, string>();
foreach (Newtonsoft.Json.Linq.JToken rule in contractualRules as Newtonsoft.Json.Linq.JToken)
{
// Use the rule's type as the key.
string key = null;
string value = null;
var index = ((string)rule["_type"]).LastIndexOf('/');
var ruleType = ((string)rule["_type"]).Substring(index + 1);
string attribution = null;
if (ruleType == "LicenseAttribution")
{
attribution = (string)rule["licenseNotice"];
}
else if (ruleType == "LinkAttribution")
{
attribution = string.Format("{0}({1})", (string)rule["text"], (string)rule["url"]);
}
else if (ruleType == "MediaAttribution")
{
attribution = (string)rule["url"];
}
else if (ruleType == "TextAttribution")
{
attribution = (string)rule["text"];
}
// If the rule targets specific data in the result; for example, the
// snippet field, use the target's name as the key. Multiple rules
// can apply to the same field.
if ((key = (string) rule["targetPropertyName"]) != null)
{
if (rules.TryGetValue(key, out value))
{
rules[key] = value + " | " + attribution;
}
else
{
rules.Add(key, attribution);
}
}
else
{
// Otherwise, the rule applies to the result. Uses 'global' as the key
// value for this case.
key = "global";
if (rules.TryGetValue(key, out value))
{
rules[key] = value + " | " + attribution;
}
else
{
rules.Add(key, attribution);
}
}
}
return rules;
}
Handling errors
This section shows an option for handling errors that the service may return. For example, the service returns an error if your subscription key is not valid or is not valid for the specified endpoint. The service may also return an error if you specify a parameter value that's not valid.
// Print any errors that occur. Depending on which part of the service is
// throwing the error, the response may contain different error formats.
static void PrintErrors(HttpResponseHeaders headers, Dictionary<String, object> response)
{
Console.WriteLine("The response contains the following errors:\n");
object value;
if (response.TryGetValue("error", out value)) // typically 401, 403
{
PrintError(response["error"] as Newtonsoft.Json.Linq.JToken);
}
else if (response.TryGetValue("errors", out value))
{
// Bing API error
foreach (Newtonsoft.Json.Linq.JToken error in response["errors"] as Newtonsoft.Json.Linq.JToken)
{
PrintError(error);
}
// Included only when HTTP status code is 400; not included with 401 or 403.
IEnumerable<string> headerValues;
if (headers.TryGetValues("BingAPIs-TraceId", out headerValues))
{
Console.WriteLine("\nTrace ID: " + headerValues.FirstOrDefault());
}
}
}
static void PrintError(Newtonsoft.Json.Linq.JToken error)
{
string value = null;
Console.WriteLine("Code: " + error["code"]);
Console.WriteLine("Message: " + error["message"]);
if ((value = (string)error["parameter"]) != null)
{
Console.WriteLine("Parameter: " + value);
}
if ((value = (string)error["value"]) != null)
{
Console.WriteLine("Value: " + value);
}
}
Next steps
- For a more in depth web app example, see the Entity web app tutorial.