How to merge PDF documents from urls asynchronously for PDF merging API in VB.NET and PDF.co Web API

Step By Step Tutorial: how to merge PDF documents from urls asynchronously for PDF merging API in VB.NET

The coding tutorials are designed to help you test the features without need to write your own code. PDF.co Web API was made to help with PDF merging API in VB.NET. PDF.co Web API is the flexible Web API that includes full set of functions from e-signature requests to data extraction, OCR, images recognition, pdf splitting and pdf splitting. Can also generate barcodes and read barcodes from images, scans and pdf.

VB.NET code snippet like this for PDF.co Web API works best when you need to quickly implement PDF merging API in your VB.NET application. For implimentation of this functionality, please copy and paste code below into your app using code editor. Then compile and run your app. Tutorials are available along with installed PDF.co Web API if you’d like to dive deeper into the topic and the details of the API.

Our website provides free trial version of PDF.co Web API that includes source code samples to help with your VB.NET project.

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Module1.vb
      
Imports System.IO Imports System.Net Imports System.Threading Imports Newtonsoft.Json.Linq ' Cloud API asynchronous "Merge 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 URLs of PDF files to merge Dim SourceFiles As String() = { "https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-merge/sample1.pdf", "https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-merge/sample2.pdf"} ' 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 `Merge PDF` API call Dim query As String = Uri.EscapeUriString(String.Format( "https://api.pdf.co/v1/pdf/merge?name={0}&url={1}&async={2}", Path.GetFileName(DestinationFile), String.Join(",", SourceFiles), 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>

ON-PREMISE OFFLINE SDK

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Explore PDF.co Web API Documentation

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ON-DEMAND REST WEB API

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ON-PREMISE OFFLINE SDK

60 Day Free Trial or Visit PDF.co Web API Home Page

Explore PDF.co Web API Documentation

Explore Samples

Sign Up for PDF.co Web API Online Training

ON-DEMAND REST WEB API

Get Your API Key

Explore Web API Docs

Explore Web API Samples

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