How to convert PDF to PNG from uploaded file for PDF to image API in VB.NET and PDF.co Web API

How to convert PDF to PNG from uploaded file in VB.NET with easy ByteScout code samples to make PDF to image API. Step-by-step tutorial

Today you are going to learn how to convert PDF to PNG from uploaded file in VB.NET. PDF.co Web API was made to help with PDF to image 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 samples for VB.NET developers help to speed up the application’s code writing when using PDF.co Web API. 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! 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.

ByteScout free trial version is available for FREE download from our website. Programming tutorials along with source code samples are included.

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Module1.vb
      
Imports System.IO Imports System.Net Imports Newtonsoft.Json.Linq Module Module1 ' The authentication key (API Key). ' Get your own by registering at https://app.pdf.co/documentation/api Const API_KEY As String = "***********************************" ' Source PDF file const SourceFile as String = ".\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 = "" 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) ' 1. RETRIEVE THE PRESIGNED URL TO UPLOAD THE FILE. ' * If you already have the direct file URL, skip to the step 3. ' Prepare URL for `Get Presigned URL` API call Dim query As string = Uri.EscapeUriString(string.Format( "https://api.pdf.co/v1/file/upload/get-presigned-url?contenttype=application/octet-stream&name={0}", Path.GetFileName(SourceFile))) 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 ' Get URL to use for the file upload Dim uploadUrl As string = json("presignedUrl").ToString() ' Get URL of uploaded file to use with later API calls Dim uploadedFileUrl As string = json("url").ToString() ' 2. UPLOAD THE FILE TO CLOUD. webClient.Headers.Add("content-type", "application/octet-stream") webClient.UploadFile(uploadUrl, "PUT", SourceFile) ' You can use UploadData() instead if your file is byte array or Stream ' 3. CONVERT UPLOADED PDF FILE TO PNG ' Prepare URL for `PDF To PNG` API call query = Uri.EscapeUriString(String.Format( "https://api.pdf.co/v1/pdf/convert/to/png?password={0}&pages={1}&url={2}", Password, Pages, uploadedFileUrl)) ' Execute request response = webClient.DownloadString(query) ' Parse JSON response json = JObject.Parse(response) If json("error").ToObject(Of Boolean) = False Then ' Download generated PNG files Dim page As Integer = 1 For Each token As JToken In json("urls") 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 Else Console.WriteLine(json("message").ToString()) End If 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 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

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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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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