How to replace text from PDF in C# and PDF.co Web API

What is PDF.co Web API? It is the Rest API that provides set of data extraction functions, tools for documents manipulation, splitting and merging of pdf files. Includes built-in OCR, images recognition, can generate and read barcodes from images, scans and pdf.

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ByteScoutWebApiExample.csproj

      
<?xml version="1.0" encoding="utf-8"?> <Project ToolsVersion="12.0" DefaultTargets="Build" 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>{1E1C2C34-017E-4605-AE2B-55EA3313BE51}</ProjectGuid> <OutputType>Exe</OutputType> <AppDesignerFolder>Properties</AppDesignerFolder> <RootNamespace>ByteScoutWebApiExample</RootNamespace> <AssemblyName>ByteScoutWebApiExample</AssemblyName> <TargetFrameworkVersion>v4.0</TargetFrameworkVersion> <FileAlignment>512</FileAlignment> </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' "> <PlatformTarget>AnyCPU</PlatformTarget> <DebugSymbols>true</DebugSymbols> <DebugType>full</DebugType> <Optimize>false</Optimize> <OutputPath>bin\Debug\</OutputPath> <DefineConstants>DEBUG;TRACE</DefineConstants> <ErrorReport>prompt</ErrorReport> <WarningLevel>4</WarningLevel> </PropertyGroup> <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' "> <PlatformTarget>AnyCPU</PlatformTarget> <DebugType>pdbonly</DebugType> <Optimize>true</Optimize> <OutputPath>bin\Release\</OutputPath> <DefineConstants>TRACE</DefineConstants> <ErrorReport>prompt</ErrorReport> <WarningLevel>4</WarningLevel> </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> <Private>True</Private> </Reference> <Reference Include="System" /> <Reference Include="System.Core" /> <Reference Include="System.Xml.Linq" /> <Reference Include="System.Data" /> <Reference Include="System.Xml" /> </ItemGroup> <ItemGroup> <Compile Include="Program.cs" /> <Compile Include="Properties\AssemblyInfo.cs" /> </ItemGroup> <ItemGroup> <None Include="packages.config" /> <Content Include="sample.pdf"> <CopyToOutputDirectory>Always</CopyToOutputDirectory> </Content> </ItemGroup> <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" /> <!-- To modify your build process, add your task inside one of the targets below and uncomment it. Other similar extension points exist, see Microsoft.Common.targets. <Target Name="BeforeBuild"> </Target> <Target Name="AfterBuild"> </Target> --> </Project>

ByteScoutWebApiExample.sln

      
Microsoft Visual Studio Solution File, Format Version 12.00 # Visual Studio 2013 VisualStudioVersion = 12.0.40629.0 MinimumVisualStudioVersion = 10.0.40219.1 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ByteScoutWebApiExample", "ByteScoutWebApiExample.csproj", "{1E1C2C34-017E-4605-AE2B-55EA3313BE51}" EndProject Global GlobalSection(SolutionConfigurationPlatforms) = preSolution Debug|Any CPU = Debug|Any CPU Release|Any CPU = Release|Any CPU EndGlobalSection GlobalSection(ProjectConfigurationPlatforms) = postSolution {1E1C2C34-017E-4605-AE2B-55EA3313BE51}.Debug|Any CPU.ActiveCfg = Debug|Any CPU {1E1C2C34-017E-4605-AE2B-55EA3313BE51}.Debug|Any CPU.Build.0 = Debug|Any CPU {1E1C2C34-017E-4605-AE2B-55EA3313BE51}.Release|Any CPU.ActiveCfg = Release|Any CPU {1E1C2C34-017E-4605-AE2B-55EA3313BE51}.Release|Any CPU.Build.0 = Release|Any CPU EndGlobalSection GlobalSection(SolutionProperties) = preSolution HideSolutionNode = FALSE EndGlobalSection EndGlobal

Program.cs

      
using System; using System.Collections.Generic; using System.IO; using System.Net; using Newtonsoft.Json; using Newtonsoft.Json.Linq; namespace ByteScoutWebApiExample { class Program { // The authentication key (API Key). // Get your own by registering at https://app.pdf.co/documentation/api const String API_KEY = "***********************************"; // Source PDF file const string SourceFile = @".\sample.pdf"; // PDF document password. Leave empty for unprotected documents. const string Password = ""; // Destination PDF file name const string DestinationFile = @".\result.pdf"; static void Main(string[] args) { // Create standard .NET web client instance WebClient 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 a direct file URL, skip to the step 3. // Prepare URL for `Get Presigned URL` API call string query = 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 string response = webClient.DownloadString(query); // Parse JSON response JObject json = JObject.Parse(response); if (json["error"].ToObject<bool>() == false) { // Get URL to use for the file upload string uploadUrl = json["presignedUrl"].ToString(); string uploadedFileUrl = 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[] or Stream // 3. Replace Text FROM UPLOADED PDF FILE // URL for `Replace Text from PDF` API call var url = "https://api.pdf.co/v1/pdf/edit/replace-text"; // Prepare requests params as JSON Dictionary<string, object> parameters = new Dictionary<string, object>(); parameters.Add("name", Path.GetFileName(DestinationFile)); parameters.Add("password", Password); parameters.Add("url", uploadedFileUrl); parameters.Add("searchString", "The most conspicuous feature of"); parameters.Add("replaceString", "replaced text"); // Convert dictionary of params to JSON string jsonPayload = 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<bool>() == false) { // Get URL of generated PDF file string resultFileUrl = 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()); } } else { Console.WriteLine(json["message"].ToString()); } } catch (WebException e) { Console.WriteLine(e.ToString()); } webClient.Dispose(); Console.WriteLine(); Console.WriteLine("Press any key..."); Console.ReadKey(); } } }

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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