How to add text and images to PDF in C# using PDF.co Web API

The tutorial shows how to add text and images to PDF in C#

The code below will help you to implement an C# app to add text and images to PDF. PDF.co Web API is the Web API with a set of tools for documents manipulation, data conversion, data extraction, splitting and merging of documents. Includes image recognition, built-in OCR, barcode generation and barcode decoders to decode bar codes from scans, pictures and pdf. It can add text and images to PDF in C#.

This code snippet below for PDF.co Web API works best when you need to quickly add text and images to PDF in your C# application. In order to implement the functionality, you should copy and paste this code for C# below into your code editor with your app, compile and run your application. Test C# sample code examples whether they respond your needs and requirements for the project.

Trial version of PDF.co Web API is available for free. Source code samples are included to help you with your C# app.

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AddTextByFindingTargetCoordinates.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> <RootNamespace>AddTextByFindingTargetCoordinates</RootNamespace> <AssemblyName>AddTextByFindingTargetCoordinates</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" /> </ItemGroup> <ItemGroup> <None Include="packages.config" /> </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>

AddTextByFindingTargetCoordinates.sln

      
Microsoft Visual Studio Solution File, Format Version 12.00 # Visual Studio 15 VisualStudioVersion = 15.0.26730.10 MinimumVisualStudioVersion = 10.0.40219.1 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AddTextByFindingTargetCoordinates", "AddTextByFindingTargetCoordinates.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 GlobalSection(ExtensibilityGlobals) = postSolution SolutionGuid = {238BD6FC-F70A-4B5C-B639-34E5B171A981} EndGlobalSection EndGlobal

Program.cs

      
using System; using System.Collections.Generic; using System.Globalization; 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 = "*****************************************"; // Direct URL of source PDF file. const string SourceFileUrl = "https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-edit/sample.pdf"; // Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'. const string Pages = ""; // PDF document password. Leave empty for unprotected documents. const string Password = ""; // Destination PDF file name const string DestinationFile = @".\result.pdf"; // Annotation params const string Type = "annotation"; const string Text = "Some notes will go here... Some notes will go here.... Some notes will go here....."; const string FontName = "Times New Roman"; const float FontSize = 12; const string FontColor = "FF0000"; 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); // * Add text annotation * // Find coordinates of key phrase to add annotation at the same Y coordinate var coordinates = FindCoordinates(API_KEY, SourceFileUrl, "Notes"); var X = coordinates.X; var Y = coordinates.Y + 25; // Prepare requests params as JSON // See documentation: https://apidocs.pdf.co/?#pdf-add-text-and-images-to-pdf Dictionary<string, string> parameters = new Dictionary<string, string>(); parameters.Add("name", Path.GetFileName(DestinationFile)); parameters.Add("password", Password); parameters.Add("pages", Pages); parameters.Add("url", SourceFileUrl); parameters.Add("type", Type); parameters.Add("x", X.ToString()); parameters.Add("y", Y.ToString()); parameters.Add("text", Text); parameters.Add("fontname", FontName); parameters.Add("size", FontSize.ToString(CultureInfo.InvariantCulture)); parameters.Add("color", FontColor); // Convert dictionary of params to JSON string jsonPayload = JsonConvert.SerializeObject(parameters); try { // URL of "PDF Edit" endpoint string url = "https://api.pdf.co/v1/pdf/edit/add"; // Execute POST request with JSON payload string response = webClient.UploadString(url, jsonPayload); // Parse JSON response JObject json = JObject.Parse(response); if (json["error"].ToObject<bool>() == false) { // Get URL of generated PDF file string resultFileUrl = json["url"].ToString(); // Download generated PDF file webClient.DownloadFile(resultFileUrl, DestinationFile); Console.WriteLine("Generated PDF file saved as \"{0}\" file.", DestinationFile); } else { Console.WriteLine(json["message"].ToString()); } } catch (WebException e) { Console.WriteLine(e.ToString()); } finally { webClient.Dispose(); } Console.WriteLine(); Console.WriteLine("Press any key..."); Console.ReadKey(); } /// <summary> /// Find text coordinates /// </summary> public static ResultCoordinates FindCoordinates(string apiKey, string sourceFileUrl, string searchString) { ResultCoordinates result = null; // Create standard .NET web client instance WebClient webClient = new WebClient(); // Set API Key webClient.Headers.Add("x-api-key", apiKey); // Prepare requests params as JSON // See documentation: https://apidocs.pdf.co/?#pdf-search-text Dictionary<string, string> parameters = new Dictionary<string, string>(); parameters.Add("url", sourceFileUrl); parameters.Add("searchString", searchString); // Convert dictionary of params to JSON string jsonPayload = JsonConvert.SerializeObject(parameters); try { // URL of "PDF Find" endpoint string url = "https://api.pdf.co/v1/pdf/find"; // Execute POST request with JSON payload string response = webClient.UploadString(url, jsonPayload); // Parse JSON response JObject json = JObject.Parse(response); if (json["status"].ToString() != "error") { JToken item = json["body"][0]; result = new ResultCoordinates { X = Convert.ToInt32(item["left"]), Y = Convert.ToInt32(item["top"]), Width = Convert.ToInt32(item["width"]), Height = Convert.ToInt32(item["height"]) }; } } catch (WebException e) { Console.WriteLine(e.ToString()); throw; } finally { webClient.Dispose(); } return result; } } public class ResultCoordinates { public int X { get; set; } public int Y { get; set; } public int Width { get; set; } public int Height { get; set; } } }

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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