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

How to convert PDF to JPEG from uploaded file for PDF to image API in VB.NET: How To Tutorial

Here you may find thousands pre-made source code pieces for easy implementation in your own programming projects. PDF to image API in VB.NET can be implemented with PDF.co Web API. 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. This VB.NET sample code should be copied and pasted into your project. After doing this just compile your project and click Run. Enjoy writing a code with ready-to-use sample VB.NET codes to add PDF to image API functions using PDF.co Web API in VB.NET.

Trial version of ByteScout is available for free download from our website. This and other source code samples for VB.NET and other programming languages are available.

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ByteScoutWebApiExample.sln

      
Microsoft Visual Studio Solution File, Format Version 12.00 # Visual Studio 15 VisualStudioVersion = 15.0.26730.10 MinimumVisualStudioVersion = 10.0.40219.1 Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "ByteScoutWebApiExample", "ByteScoutWebApiExample.vbproj", "{9B91124C-66C3-4BD9-B29E-168C1ABB15AC}" EndProject Global GlobalSection(SolutionConfigurationPlatforms) = preSolution Debug|Any CPU = Debug|Any CPU Release|Any CPU = Release|Any CPU EndGlobalSection GlobalSection(ProjectConfigurationPlatforms) = postSolution {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Debug|Any CPU.Build.0 = Debug|Any CPU {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Release|Any CPU.ActiveCfg = Release|Any CPU {9B91124C-66C3-4BD9-B29E-168C1ABB15AC}.Release|Any CPU.Build.0 = Release|Any CPU EndGlobalSection GlobalSection(SolutionProperties) = preSolution HideSolutionNode = FALSE EndGlobalSection GlobalSection(ExtensibilityGlobals) = postSolution SolutionGuid = {4576C9BB-A42D-46A8-9198-7E2982E122FA} EndGlobalSection EndGlobal

ByteScoutWebApiExample.vbproj

      
<?xml version="1.0" encoding="utf-8"?> <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003"> <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" /> <PropertyGroup> <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration> <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform> <ProjectGuid>{9B91124C-66C3-4BD9-B29E-168C1ABB15AC}</ProjectGuid> <OutputType>Exe</OutputType> <StartupObject>ByteScoutWebApiExample.Module1</StartupObject> <RootNamespace>ByteScoutWebApiExample</RootNamespace> <AssemblyName>ByteScoutWebApiExample</AssemblyName> <FileAlignment>512</FileAlignment> <MyType>Console</MyType> <TargetFrameworkVersion>v4.0</TargetFrameworkVersion> </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' "> <PlatformTarget>AnyCPU</PlatformTarget> <DebugSymbols>true</DebugSymbols> <DebugType>full</DebugType> <DefineDebug>true</DefineDebug> <DefineTrace>true</DefineTrace> <OutputPath>bin\Debug\</OutputPath> <DocumentationFile>ByteScoutWebApiExample.xml</DocumentationFile> <NoWarn>42016,41999,42017,42018,42019,42032,42036,42020,42021,42022</NoWarn> </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' "> <PlatformTarget>AnyCPU</PlatformTarget> <DebugType>pdbonly</DebugType> <DefineDebug>false</DefineDebug> <DefineTrace>true</DefineTrace> <Optimize>true</Optimize> <OutputPath>bin\Release\</OutputPath> <DocumentationFile>ByteScoutWebApiExample.xml</DocumentationFile> <NoWarn>42016,41999,42017,42018,42019,42032,42036,42020,42021,42022</NoWarn> </PropertyGroup> <PropertyGroup> <OptionExplicit>On</OptionExplicit> </PropertyGroup> <PropertyGroup> <OptionCompare>Binary</OptionCompare> </PropertyGroup> <PropertyGroup> <OptionStrict>Off</OptionStrict> </PropertyGroup> <PropertyGroup> <OptionInfer>On</OptionInfer> </PropertyGroup> <ItemGroup> <Reference Include="Newtonsoft.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL"> <HintPath>packages\Newtonsoft.Json.10.0.3\lib\net40\Newtonsoft.Json.dll</HintPath> </Reference> <Reference Include="System" /> <Reference Include="System.Data" /> <Reference Include="System.Deployment" /> <Reference Include="System.Xml" /> <Reference Include="System.Core" /> <Reference Include="System.Xml.Linq" /> <Reference Include="System.Data.DataSetExtensions" /> </ItemGroup> <ItemGroup> <Import Include="Microsoft.VisualBasic" /> <Import Include="System" /> <Import Include="System.Collections" /> <Import Include="System.Collections.Generic" /> <Import Include="System.Data" /> <Import Include="System.Diagnostics" /> <Import Include="System.Linq" /> <Import Include="System.Xml.Linq" /> </ItemGroup> <ItemGroup> <Compile Include="Module1.vb" /> <Compile Include="My Project\AssemblyInfo.vb" /> <Compile Include="My Project\Application.Designer.vb"> <AutoGen>True</AutoGen> <DependentUpon>Application.myapp</DependentUpon> </Compile> <Compile Include="My Project\Resources.Designer.vb"> <AutoGen>True</AutoGen> <DesignTime>True</DesignTime> <DependentUpon>Resources.resx</DependentUpon> </Compile> <Compile Include="My Project\Settings.Designer.vb"> <AutoGen>True</AutoGen> <DependentUpon>Settings.settings</DependentUpon> <DesignTimeSharedInput>True</DesignTimeSharedInput> </Compile> </ItemGroup> <ItemGroup> <EmbeddedResource Include="My Project\Resources.resx"> <Generator>VbMyResourcesResXFileCodeGenerator</Generator> <LastGenOutput>Resources.Designer.vb</LastGenOutput> <CustomToolNamespace>My.Resources</CustomToolNamespace> <SubType>Designer</SubType> </EmbeddedResource> </ItemGroup> <ItemGroup> <None Include="My Project\Application.myapp"> <Generator>MyApplicationCodeGenerator</Generator> <LastGenOutput>Application.Designer.vb</LastGenOutput> </None> <None Include="My Project\Settings.settings"> <Generator>SettingsSingleFileGenerator</Generator> <CustomToolNamespace>My</CustomToolNamespace> <LastGenOutput>Settings.Designer.vb</LastGenOutput> </None> <None Include="packages.config" /> <Content Include="sample.pdf"> <CopyToOutputDirectory>Always</CopyToOutputDirectory> </Content> </ItemGroup> <Import Project="$(MSBuildToolsPath)\Microsoft.VisualBasic.targets" /> </Project>

Module1.vb

      
Imports System.IO Imports System.Net Imports Newtonsoft.Json 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 ' Set JSON content type webClient.Headers.Add("Content-Type", "application/json") ' 3. CONVERT UPLOADED PDF FILE TO JPEG ' Prepare URL for `PDF To JPEG` API call Dim url As String = "https://api.pdf.co/v1/pdf/convert/to/jpg" ' Prepare requests params as JSON ' See documentation: https : //apidocs.pdf.co Dim parameters As New Dictionary(Of String, Object) parameters.Add("password", Password) parameters.Add("pages", Pages) parameters.Add("url", uploadedFileUrl) ' Convert dictionary of params to JSON Dim jsonPayload As String = JsonConvert.SerializeObject(parameters) ' Execute POST request with JSON payload response = webClient.UploadString(url, jsonPayload) ' Parse JSON response json = JObject.Parse(response) If json("error").ToObject(Of Boolean) = False Then ' Download generated JPEG 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}.jpg", 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

packages.config

      
<?xml version="1.0" encoding="utf-8"?> <packages> <package id="Newtonsoft.Json" version="10.0.3" targetFramework="net40" /> </packages>

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