Cloud API - PDF To Image API - VB.NET - Convert PDF To PNG From Uploaded File - ByteScout

Cloud API – PDF To Image API – VB.NET – Convert PDF To PNG From Uploaded File

  • Home
  • /
  • Articles
  • /
  • Cloud API – PDF To Image API – VB.NET – Convert PDF To PNG From Uploaded File

Cloud API – PDF To Image API – VB.NET – Convert PDF To PNG From Uploaded File

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


  Click here to get your Free Trial version of the SDK

Tutorials:

prev
next