How to optimize PDF from URL asynchronously for PDF optimization API in VB.NET using PDF.co Web API

See how to optimize PDF from URL asynchronously to have PDF optimization API in VB.NET

Here you may find thousands pre-made source code pieces for easy implementation in your own programming projects. PDF.co Web API was made to help with PDF optimization API in VB.NET. PDF.co Web API is the Web API with a set of tools for documents manipulation, data conversion, data extraction, splitting and merging of documents. Includes image recognition, built-in OCR, barcode generation and barcode decoders to decode bar codes from scans, pictures and pdf.

VB.NET code snippet like this for PDF.co Web API works best when you need to quickly implement PDF optimization API in your VB.NET application. Sample code in VB.NET is all you need. Copy-paste it to your the code editor, then add a reference to PDF.co Web API and you are ready to try it! Further enhancement of the code will make it more vigorous.

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Module1.vb
      
Imports System.IO Imports System.Net Imports System.Threading Imports Newtonsoft.Json.Linq ' Cloud API asynchronous "Optimize PDF" job example. ' Allows to avoid timeout errors when processing huge or scanned PDF documents. Module Module1 ' The authentication key (API Key). ' Get your own by registering at https://app.pdf.co/documentation/api Const API_KEY As String = "***********************************" ' Direct URL of source PDF file. Const SourceFileUrl As String = "https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-optimize/sample.pdf" ' PDF document password. Leave empty for unprotected documents. Const Password As String = "" ' Destination PDF file name Const DestinationFile As String = ".\result.pdf" ' (!) Make asynchronous job Const Async As Boolean = True Sub Main() ' Create standard .NET web client instance Dim webClient As WebClient = New WebClient() ' Set API Key webClient.Headers.Add("x-api-key", API_KEY) ' Prepare URL for `Optimize PDF` API call Dim query As String = Uri.EscapeUriString(String.Format( "https://api.pdf.co/v1/pdf/optimize?name={0}&password={1}&url={2}&async={3}", Path.GetFileName(DestinationFile), Password, SourceFileUrl, Async)) Try ' Execute request Dim response As String = webClient.DownloadString(query) ' Parse JSON response Dim json As JObject = JObject.Parse(response) If json("error").ToObject(Of Boolean) = False Then ' Asynchronous job ID Dim jobId As String = json("jobId").ToString() ' URL of generated PDF file that will available after the job completion Dim resultFileUrl As String = 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 Dim status As String = CheckJobStatus(jobId) ' Possible statuses: "working", "failed", "aborted", "success". ' Display timestamp and status (for demo purposes) Console.WriteLine(DateTime.Now.ToLongTimeString() + ": " + status) If status = "success" Then ' Download PDF file webClient.DownloadFile(resultFileUrl, DestinationFile) Console.WriteLine("Generated PDF file saved as ""{0}"" file.", DestinationFile) Exit Do ElseIf status = "working" Then ' Pause for a few seconds Thread.Sleep(3000) Else Console.WriteLine(status) Exit Do End If Loop Else Console.WriteLine(json("message").ToString()) End If Catch ex As WebException Console.WriteLine(ex.ToString()) End Try webClient.Dispose() Console.WriteLine() Console.WriteLine("Press any key...") Console.ReadKey() End Sub Function CheckJobStatus(jobId As String) As String Using webClient As WebClient = New WebClient() ' Set API Key webClient.Headers.Add("x-api-key", API_KEY) Dim url As String = "https://api.pdf.co/v1/job/check?jobid=" + jobId Dim response As String = webClient.DownloadString(url) Dim json As JObject = JObject.Parse(response) return Convert.ToString(json("status")) End Using End Function End Module

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packages.config
      
<?xml version="1.0" encoding="utf-8"?> <packages> <package id="Newtonsoft.Json" version="10.0.3" targetFramework="net40" /> </packages>

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