PDF.co Web API – PDF Merging API – VB.NET – Merge PDF Documents From URLs Asynchronously

On-demand (REST Web API) version:
 Web API (on-demand version)

On-premise offline SDK for Windows:
 60 Day Free Trial (on-premise)

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" />
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.VisualBasic.targets" />
</Project>
    

Module1.vb

      
Imports System.IO
Imports System.Net
Imports System.Threading
Imports Newtonsoft.Json
Imports Newtonsoft.Json.Linq


' Cloud API asynchronous "Merge PDF" job example.
' Allows to avoid timeout errors when processing huge or scanned PDF documents.

Module Module1

	' The authentication key (API Key).
	' Get your own by registering at https://app.pdf.co/documentation/api
	Const API_KEY As String = "***********************************"

	' Direct URLs of PDF files to merge
	Dim SourceFiles As String() = {
		"https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-merge/sample1.pdf",
		"https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-merge/sample2.pdf"}
	' Destination PDF file name
	Const DestinationFile As String = ".\result.pdf"
	' (!) Make asynchronous job
	Const Async As Boolean = True


	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)

        ' Set JSON content type
        webClient.Headers.Add("Content-Type", "application/json")

		' Prepare URL for `Merge PDF` API call
		Dim url As String = "https://api.pdf.co/v1/pdf/merge"

        ' Prepare requests params as JSON
        ' See documentation: https : //apidocs.pdf.co
        Dim parameters As New Dictionary(Of String, Object)
		parameters.Add("name", Path.GetFileName(DestinationFile))
		parameters.Add("url", String.Join(",", SourceFiles))
		parameters.Add("async", Async)

        ' Convert dictionary of params to JSON
        Dim jsonPayload As String = JsonConvert.SerializeObject(parameters)

		Try
			' Execute POST request with JSON payload
			Dim response As String = webClient.UploadString(url, jsonPayload)

			' 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 PDF file that will available after the job completion
				Dim resultFileUrl 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 PDF file
						webClient.DownloadFile(resultFileUrl, DestinationFile)

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

			' Set API Key
			webClient.Headers.Add("x-api-key", API_KEY)
			
			Dim url As String = "https://api.pdf.co/v1/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

    

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

Get 60 Day Free Trial

See also:

• Explore Documentation
• Explore Source Code Samples
• Watch Video Course

ON-DEMAND REST WEB API

Get Your API Key

See also:

• Web API Docs
• Learn About Security
• Explore Source Code Samples