PDF.co Web API – Barcode Reader API – C# – Read Barcode From URL Asynchronously

PDF.co Web API – Barcode Reader API – C# – Read Barcode From URL Asynchronously

Program.cs

using System;
using System.IO;
using System.Net;
using System.Threading;
using System.Threading.Tasks;
using Newtonsoft.Json.Linq;

// Cloud API asynchronous "Barcode Reader" job example.
// Allows to avoid timeout errors when processing huge or scanned PDF documents.


namespace ByteScoutWebApiExample
{
	class Program
	{
		// The authentication key (API Key).
		// Get your own by registering at https://app.pdf.co/documentation/api
		const String API_KEY = "***********************************";
		
		// Direct URL of source file (image or PDF) to search barcodes in.
		const string SourceFileURL = "https://s3-us-west-2.amazonaws.com/bytescout-com/files/demo-files/cloud-api/barcode-reader/sample.pdf";
		// Comma-separated list of barcode types to search. 
		// See valid barcode types in the documentation https://app.pdf.co/documentation/api/1.0/barcode/read_from_url.html
		const string BarcodeTypes = "Code128,Code39,Interleaved2of5,EAN13";
		// Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
		const string Pages = "";
		// (!) Make asynchronous job
		const bool Async = true;

		static void Main(string[] args)
		{
			// Create standard .NET web client instance
			WebClient webClient = new WebClient();

			// Set API Key
			webClient.Headers.Add("x-api-key", API_KEY);

			// Prepare URL for `Barcode Reader` API call
			string query = Uri.EscapeUriString(string.Format("https://api.pdf.co/v1/barcode/read/from/url?types={0}&pages={1}&url={2}&async={3}", 
				BarcodeTypes,
				Pages,
				SourceFileURL, 
				Async));

			try
			{
				// Execute request
				string response = webClient.DownloadString(query);

				// Parse JSON response
				JObject json = JObject.Parse(response);

				if (json["error"].ToObject<bool>() == false)
				{
					// Asynchronous job ID
					string jobId = json["jobId"].ToString();
					// URL of generated JSON file with decoded barcodes that will available after the job completion
					string resultFileUrl = json["url"].ToString();

					// Check the job status in a loop. 
					// If you don't want to pause the main thread you can rework the code 
					// to use a separate thread for the status checking and completion.
					do
					{
						string status = CheckJobStatus(jobId); // Possible statuses: "InProgress", "Failed", "Aborted", "Finished".

						// Display timestamp and status (for demo purposes)
						Console.WriteLine(DateTime.Now.ToLongTimeString() + ": " + status);

						if (status == "Finished")
						{
							// Download JSON results file as string
							string jsonFileString = webClient.DownloadString(resultFileUrl);

							JArray jsonFoundBarcodes = JArray.Parse(jsonFileString);
							
							// Display found barcodes in console
							foreach (JToken token in jsonFoundBarcodes)
							{
								Console.WriteLine("Found barcode:");
								Console.WriteLine("  Type: " + token["TypeName"]);
								Console.WriteLine("  Value: " + token["Value"]);
								Console.WriteLine("  Document Page Index: " + token["Page"]);
								Console.WriteLine("  Rectangle: " + token["Rect"]);
								Console.WriteLine("  Confidence: " + token["Confidence"]);
								Console.WriteLine();
							}
							break;
						}
						else if (status == "InProgress")
						{
							// Pause for a few seconds
							Thread.Sleep(3000);
						}
						else
						{
							Console.WriteLine(status);
							break;
						}
					}
					while (true);
				}
				else
				{
					// Display service reported error
					Console.WriteLine(json["message"].ToString());
				}
			}
			catch (WebException e)
			{
				// Display request error
				Console.WriteLine(e.ToString());
			}

			webClient.Dispose();


			Console.WriteLine();
			Console.WriteLine("Press any key...");
			Console.ReadKey();
		}

		static string CheckJobStatus(string jobId)
		{
			using (WebClient webClient = new WebClient())
			{
				// Set API Key
                webClient.Headers.Add("x-api-key", API_KEY);
				
				string url = "https://api.pdf.co/v1/job/check?jobid=" + jobId;

				string response = webClient.DownloadString(url);
				JObject json = JObject.Parse(response);

				return Convert.ToString(json["Status"]);
			}
		}
	}
}

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