Save PDF files to Google Drive

21 Oct 20255 minutes to read

To save a PDF file to Google Drive using the ASP.NET MVC PDF Viewer, follow the steps below. This approach uses a server-backed web service.

Step 1: Set up the Google Drive API

Create a project in the Google Cloud Console and enable the Google Drive API. Obtain the necessary credentials to access the API. For more information, see the official guide

Step 2: Create an ASP.NET MVC PDF Viewer sample

Follow the instructions in this 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 System.IO;
using Google.Apis.Drive.v3;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;
using Google.Apis.Util.Store;

1. Modify the Download() method to save the downloaded PDF files to the Google Drive folder.

    // Specify the path to the credentials file
    private string credentialsPath = "Your Path to the OAuth 2.0 Client IDs json file";
    // Specify the folder ID where you want to upload the PDF on Google Drive
    private readonly string folderId = "Your Google Drive Folder ID";
    private readonly string ApplicationName = "Your Application Name";
    private readonly string tokenjson = "Path to create token.json file";

  public async Task<ActionResult> Download(jsonObjects jsonObject)
 {
     PdfRenderer pdfviewer = new PdfRenderer();
     var jsonData = JsonConverter(jsonObject);
     string[] Scopes = { DriveService.Scope.DriveFile };

     // Download the PDF document
     string documentBase = pdfviewer.GetDocumentAsBase64(jsonData);
     byte[] documentBytes = Convert.FromBase64String(documentBase.Split(',')[1]);
     string documentId = jsonData["documentId"];
     string result = Path.GetFileNameWithoutExtension(documentId);
     string fileName = result + "_downloaded.pdf";

     UserCredential credential;

     using (var streammen = new FileStream(credentialsPath, FileMode.Open, FileAccess.Read))
     {
         // The file token.json stores the user's access and refresh tokens and is created
         // automatically when the authorization flow completes for the first time.
         string tokenPath = tokenjson;
         credential = await GoogleWebAuthorizationBroker.AuthorizeAsync(
             GoogleClientSecrets.Load(streammen).Secrets,
             Scopes,
             "user",
             CancellationToken.None,
             new FileDataStore(tokenPath, true));
     }

     // Create the Drive API service
     var service = new DriveService(new BaseClientService.Initializer()
     {
         HttpClientInitializer = credential,
         ApplicationName = ApplicationName,
     });

     // Create file metadata
     var fileMetadata = new Google.Apis.Drive.v3.Data.File()
     {
         Name = fileName,
         Parents = new List<string> { folderId }
     };

     FilesResource.CreateMediaUpload request;

     // Upload the file to Google Drive
     using (var stream = new MemoryStream(documentBytes))
     {
         request = service.Files.Create(fileMetadata, stream, "application/pdf");
         request.Fields = "id";
         var uploadedFile = await request.UploadAsync();
     }

     return Content(documentBase);
 }

NOTE

Replace the placeholders with the actual Google Drive folder ID, application name, and the path to the OAuth 2.0 Client IDs JSON file. The folder ID is the unique identifier in the folder URL. For example, in https://drive.google.com/drive/folders/abc123xyz456, the ID is abc123xyz456.

Step 4: Set the PDF Viewer properties in the ASP.NET MVC PDF Viewer component

Set the documentPath property of the PDF Viewer component to the desired PDF file name that you wish to load from Google Drive. Ensure that the document exists in the target 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

Install the Google.Apis.Drive.v3 NuGet package in the application to use the previous code example.

View sample in GitHub