Important Update
These source code samples are listed and grouped by their programming language and functions they use. ByteScout Cloud API Server was designed to assist PDF to image API in VB.NET. ByteScout Cloud API Server is the ready to deploy Web API Server that can be deployed in less than thirty minutes into your own in-house Windows server (no Internet connnection is required to process data!) or into private cloud server. Can store data on in-house local server based storage or in Amazon AWS S3 bucket. Processing data solely on the server using built-in ByteScout powered engine, no cloud services are used to process your data!.
VB.NET code snippet like this for ByteScout Cloud API Server works best when you need to quickly implement PDF to image API in your VB.NET application. This VB.NET sample code can be used by copying and pasting into your project. Once done,just compile your project and click Run. Want to see how it works with your data then code testing will allow the function to be tested and work properly.
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Imports System.IO
Imports System.Net
Imports System.Threading
Imports Newtonsoft.Json.Linq
' Please NOTE: In this sample we're assuming Cloud Api Server is hosted at "https://localhost".
' If it's not then please replace this with with your hosting url.
' Cloud API asynchronous "PDF To PNG" job example.
' Allows to avoid timeout errors when processing huge or scanned PDF documents.
Module Module1
' Source PDF file
Const SourceFileUrl As String = "https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-to-image/sample.pdf"
' Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
Const Pages As String = ""
' PDF document password. Leave empty for unprotected documents.
Const Password As String = ""
' (!) Make asynchronous job
Const Async As Boolean = True
Sub Main()
' Create standard .NET web client instance
Dim webClient As WebClient = New WebClient()
' Prepare URL for `PDF To PNG` API call
Dim query As String = Uri.EscapeUriString(String.Format(
"https://localhost/pdf/convert/to/png?password={0}&pages={1}&url={2}&async={3}",
Password,
Pages,
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 JSON file available after the job completion; it will contain URLs of result PNG files.
Dim resultJsonFileUrl 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 JSON file as string
Dim jsonFileString As String = webClient.DownloadString(resultJsonFileUrl)
Dim resultFilesUrls As JArray = JArray.Parse(jsonFileString)
' Download generated PNG files
Dim page As Integer = 1
For Each token As JToken In resultFilesUrls
Dim resultFileUrl As String = token.ToString()
Dim localFileName As String = String.Format(".\page{0}.png", page)
webClient.DownloadFile(resultFileUrl, localFileName)
Console.WriteLine("Downloaded ""{0}"".", localFileName)
page = page + 1
Next
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()
Dim url As String = "https://localhost/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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<?xml version="1.0" encoding="utf-8"?>
<packages>
<package id="Newtonsoft.Json" version="10.0.3" targetFramework="net40" />
</packages>
60 Day Free Trial or Visit ByteScout Cloud API Server Home Page
Explore ByteScout Cloud API Server Documentation
Explore Samples
Sign Up for ByteScout Cloud API Server Online Training
Get Your API Key
Explore Web API Docs
Explore Web API Samples
60 Day Free Trial or Visit ByteScout Cloud API Server Home Page
Explore ByteScout Cloud API Server Documentation
Explore Samples
Sign Up for ByteScout Cloud API Server Online Training
Get Your API Key
Explore Web API Docs
Explore Web API Samples