Convert Images To PDF From Uploaded Files | VB.NET | Image To PDF APIByteScout PDF SDK

Convert Images To PDF From Uploaded Files | VB.NET | Image To PDF API

Module1.vb:

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 image files
    Dim ImageFiles() As String = New String() {".\image1.png", ".\image2.jpg"}
    ' Destination PDF file name
    Const DestinationFile As String = ".\result.pdf"

    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. UPLOAD FILES TO CLOUD

        Dim uploadedFiles As List(Of String) = New List(Of String)()

        Try
            For Each imageFile As String In ImageFiles

                ' 1a. RETRIEVE THE PRESIGNED URL TO UPLOAD THE FILE.

                ' 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(imageFile)))

                ' 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()

                    ' 1b. UPLOAD THE FILE TO CLOUD.

                    webClient.Headers.Add("content-type", "application/octet-stream")
                    webClient.UploadFile(uploadUrl, "PUT", imageFile) ' You can use UploadData() instead if your file is byte[] or Stream

                    uploadedFiles.Add(uploadedFileUrl)
                Else
                    Console.WriteLine(json("message").ToString())
                End If

            Next

            If uploadedFiles.Count > 0 Then

                ' 2. CREATE PDF DOCUMENT FROM UPLOADED IMAGE FILES

                ' Prepare URL for `Image To PDF` API call
                Dim query As String = Uri.EscapeUriString(String.Format(
                    "https://api.pdf.co/v1/pdf/convert/from/image?name={0}&url={1}",
                    Path.GetFileName(DestinationFile),
                    String.Join(",", uploadedFiles)))

                ' 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 of generated PDF file
                    Dim resultFileUrl As String = json("url").ToString()

                    ' Download PDF file
                    webClient.DownloadFile(resultFileUrl, DestinationFile)

                    Console.WriteLine("Generated PDF file saved as ""{0}"" file.", DestinationFile)

                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