Open PDF files

6 Jul 20249 minutes to read

You might need to open and view the PDF files from various location. In this section, you can find the information about how to open PDF files from URL, database and as base64 string.

Opening a PDF from URL

If you have your PDF files in the web, you can open it in the viewer using URL.

Step 1: Create a Simple PDF Viewer Sample in JavaScript

Start by following the steps provided in this link to create a simple PDF viewer sample in JavaScript. This will give you a basic setup of the PDF viewer component.

Step 2: Modify the PdfViewerController.cs File in the Web Service Project

  1. Create a web service project in .NET Core 3.0 or above. You can refer to this link for instructions on how to create a web service project.

  2. Open the PdfViewerController.cs file in your web service project.

  3. Modify the Load() method to open it in the viewer using URL

public IActionResult Load([FromBody] Dictionary<string, string> jsonData)
{
  // Initialize the PDF viewer object with memory cache object
  PdfRenderer pdfviewer = new PdfRenderer(_cache);
  MemoryStream stream = new MemoryStream();
  object jsonResult = new object();

  if (jsonObject != null && jsonObject.ContainsKey("document"))
  {
    if (bool.Parse(jsonObject["isFileName"]))
    {
      string documentPath = GetDocumentPath(jsonData["document"]);
      if (!string.IsNullOrEmpty(documentPath))
      {
        byte[] bytes = System.IO.File.ReadAllBytes(documentPath);
        stream = new MemoryStream(bytes);
      }
      else
      {
        string fileName = jsonData["document"].Split(new string[] { "://" }, StringSplitOptions.None)[0];
        if (fileName == "http" || fileName == "https")
        {
          WebClient WebClient = new WebClient();
          byte[] pdfDoc = WebClient.DownloadData(jsonData["document"]);
          stream = new MemoryStream(pdfDoc);
        }
        else
        {
          return this.Content(jsonData["document"] + " is not found");
        }
      }
    }
    else
    {
      byte[] bytes = Convert.FromBase64String(jsonObject["document"]);
      stream = new MemoryStream(bytes);
    }
  }
  jsonResult = pdfviewer.Load(stream, jsonObject);
  return Content(JsonConvert.SerializeObject(jsonResult));
}

Step 3: Set the PDF Viewer Properties in React PDF viewer component

Modify the serviceUrl property of the PDF viewer component with the accurate URL of your web service project, replacing https://localhost:44396/pdfviewer with the actual URL of your server.Modify the documentPath with the correct PDF Document URL want to load.

import { PdfViewer, Toolbar, Magnification, Navigation, LinkAnnotation,ThumbnailView,
         BookmarkView, TextSelection, Annotation, FormFields, FormDesigner} from '@syncfusion/ej2-pdfviewer';

PdfViewer.Inject( Toolbar,Magnification,Navigation, LinkAnnotation,ThumbnailView,
                  BookmarkView, TextSelection, Annotation, FormFields, FormDesigner);

let viewer: PdfViewer = new PdfViewer();
// Replace correct PDF Document URL want to load
viewer.documentPath="https://cdn.syncfusion.com/content/PDFViewer/flutter-succinctly.pdf"
// Replace the "localhost:44396" with the actual URL of your server
viewer.serviceUrl = 'https://localhost:44396/pdfviewer';
viewer.appendTo('#pdfViewer');

View sample in GitHub

Opening a PDF from base64 data

The following steps explains how the PDF file can be loaded in PDF Viewer as base64 string.

Step 1: Create a Simple PDF Viewer Sample in Angular

Start by following the steps provided in this link to create a simple PDF viewer sample in Angular. This will give you a basic setup of the PDF viewer component.

Step 2: Use the following code snippet to load PDF document using base64 string.

<button id='load'>LoadDocumentFromBase64</button>

// Load PDF document from Base64 string
document.getElementById('load').addEventListener('click', () => {
  viewer.load(
    'data:application/pdf;base64,'+ AddBase64String, null);
}

View sample in GitHub

Opening a PDF from database

To load a PDF file from SQL Server database in a PDF Viewer, you can follow the steps below

Step 1: Create a Simple PDF Viewer Sample in JavaScript

Start by following the steps provided in this link to create a simple PDF viewer sample in JavaScript. This will give you a basic setup of the PDF viewer component.

Step 2: Modify the PdfViewerController.cs File in the Web Service Project

  1. Create a web service project in .NET Core 3.0 or above. You can refer to this link for instructions on how to create a web service project.

  2. Open the PdfViewerController.cs file in your web service project.

  3. Import the required namespaces at the top of the file:

using System.IO;
using System.Data.SqlClient;
  1. Add the following private fields and constructor parameters to the PdfViewerController class, In the constructor, assign the values from the configuration to the corresponding fields
private IConfiguration _configuration;
public readonly string _connectionString;

public PdfViewerController(IWebHostEnvironment hostingEnvironment, IMemoryCache cache, IConfiguration configuration)
{
  _hostingEnvironment = hostingEnvironment;
  _cache = cache;
  _configuration = configuration;
  _connectionString = _configuration.GetValue<string>("ConnectionString");
}
  1. Modify the Load() method to open it in the viewer using URL
public IActionResult Load([FromBody] Dictionary<string, string> jsonData)
{
  // Initialize the PDF viewer object with memory cache object
  PdfRenderer pdfviewer = new PdfRenderer(_cache);
  MemoryStream stream = new MemoryStream();
  object jsonResult = new object();

  if (jsonObject != null && jsonObject.ContainsKey("document"))
  {
    if (bool.Parse(jsonObject["isFileName"]))
    {
      string documentPath = GetDocumentPath(jsonData["document"]);
      if (!string.IsNullOrEmpty(documentPath))
      {
        byte[] bytes = System.IO.File.ReadAllBytes(documentPath);
        stream = new MemoryStream(bytes);
      }
      string documentName = jsonObject["document"];

      string connectionString = _connectionString;
      System.Data.SqlClient.SqlConnection connection = new System.Data.SqlClient.SqlConnection(connectionString);

      //Searches for the PDF document from the database
      string query = "SELECT FileData FROM Table WHERE FileName = '" + documentName + "'";
      System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand(query, connection);
      connection.Open();

      using (SqlDataReader reader = command.ExecuteReader())
      {
        if (reader.Read())
        {
          byte[] byteArray = (byte[])reader["FileData"];
          stream = new MemoryStream(byteArray);
        }
      }
    }
    else
    {
      byte[] bytes = Convert.FromBase64String(jsonObject["document"]);
      stream = new MemoryStream(bytes);
    }
  }
  jsonResult = pdfviewer.Load(stream, jsonObject);
  return Content(JsonConvert.SerializeObject(jsonResult));
}
  1. Open the appsettings.json file in your web service project, Add the following lines below the existing "AllowedHosts" configuration
{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "ConnectionString": "Your connection string for SQL server"
}

NOTE

Replace Your Connection string from SQL server with the actual connection string for your SQL Server database

NOTE

The System.Data.SqlClient package must be installed in your application to use the previous code example. You need to modify the connectionString variable in the previous code example as per the connection string of your database.

View sample in GitHub