Open PDF from Box cloud storage in ASP.NET MVC

17 Nov 20255 minutes to read

Follow these steps to load a PDF from Box cloud storage using the server-backed PDF Viewer.

Step 1: Set up a Box developer account and create a Box application

To access Box storage programmatically, you’ll need a developer account with Box. Go to the Box Developer Console, sign in or create a new account, and then create a new Box application. This application will provide you with the necessary credentials Client ID and Client Secret to authenticate and access Box APIs. Before accessing files, you need to authenticate your application to access your Box account. Box API supports OAuth 2.0 authentication for this purpose.

Step 2: Create a PDF Viewer sample in ASP.NET MVC

Follow instructions provided in the Syncfusion^® PDF Viewer Getting Started Guide to create a simple PDF Viewer sample in ASP.NET MVC.

Step 3: Modify the HomeController.cs file in the project

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

using Box.V2;
using Box.V2.Auth;
using Box.V2.Config;
using Box.V2.Models;

1. Modify the Load() method to load the PDF files from Box cloud file storage.

 private readonly string _clientId = "Your_Box_Storage_ClientID";
 private readonly string _clientSecret = "Your_Box_Storage_ClientSecret";
 private readonly string _accessToken = "Your_Box_Storage_Access_Token";
 private readonly string _folderId = "Your_Folder_ID";

 [System.Web.Mvc.HttpPost]

 public async Task<ActionResult> Load(jsonObjects jsonObject)
 {
     PdfRenderer pdfviewer = new PdfRenderer();
     MemoryStream stream = new MemoryStream();
     var jsonData = JsonConverter(jsonObject);
     object jsonResult = new object();
     if (jsonObject != null && jsonData.ContainsKey("document"))
     {
         if (bool.Parse(jsonData["isFileName"]))
         {
             string objectName = jsonData["document"];
             // Initialize the Box API client with your authentication credentials
             var auth = new OAuthSession(_accessToken, "YOUR_REFRESH_TOKEN", 3600, "bearer");
             var config = new BoxConfigBuilder(_clientId, _clientSecret, new Uri("http://boxsdk")).Build();
             var client = new BoxClient(config, auth);

             // Download the file from Box storage
             var items = await client.FoldersManager.GetFolderItemsAsync(_folderId, 1000, autoPaginate: true);
             var files = items.Entries.Where(i => i.Type == "file");

             // Filter the files based on the objectName
             var matchingFile = files.FirstOrDefault(file => file.Name == objectName);

             // Fetch the file from Box storage by its name
             var fileStream = await client.FilesManager.DownloadAsync(matchingFile.Id);
             stream = new MemoryStream();
             await fileStream.CopyToAsync(stream);

             // Reset the position to the beginning of the stream
             stream.Position = 0;
         }
         else
         {
             byte[] bytes = Convert.FromBase64String(jsonData["document"]);
             stream = new MemoryStream(bytes);

         }
     }
     jsonResult = pdfviewer.Load(stream, jsonData);
     return Content(JsonConvert.SerializeObject(jsonResult));
 }

NOTE

replace Your_Box_Storage_Access_Token with your actual box access token, and Your_Folder_ID with the ID of the folder in your box storage where you want to perform specific operations. Remember to use your valid box API credentials, as Your_Box_Storage_ClientID and Your_Box_Storage_ClientSecret” are placeholders for your application’s API key and secret.

Step 4: Configure the PDF Viewer component

Set the serviceUrl to your web service endpoint (replace the localhost URL with your server URL). Set documentPath to the PDF file name to load from Box cloud storage. Ensure the document name exists in your Box folder.

@{
    ViewBag.Title = "Home Page";
}

<div>
    <div style="height:500px;width:100%;">
        @Html.EJS().PdfViewer("pdfviewer").ServiceUrl(VirtualPathUtility.ToAbsolute("~/Home/")).DocumentPath("PDF_Succinctly.pdf").Render()
    </div>
</div>

NOTE

The Box.V2.Core NuGet package must be installed in your application to use the previous code example.

NOTE

Replace PDF_Succinctly.pdf with the actual document name that you want to load from Box cloud file storage. Make sure to pass the document name from the box folder to the documentPath property of the PDF viewer component

View sample in GitHub