Open and Save Presentation in Dropbox Cloud Storage
3 Aug 202614 minutes to read
Prerequisites
- Create a Dropbox API App from the Dropbox App Console. In the App Console, set the required permission scope to
files.content.read(for opening) andfiles.content.write(for saving), then generate an access token for the app. This token authenticates programmatic access to your Dropbox account. - Store the access token securely using
appsettings.json, environment variables, or the Secret Manager — do not hard-code it in production code.
Open Presentation from Dropbox Cloud Storage
Steps to open a Presentation from Dropbox Cloud Storage.
Step 1: Create a new ASP.NET Core Web Application (Model-View-Controller).
Step 2: Name the project.
Step 3: Install the following Nuget packages in your application from NuGet.org.
Step 4: Add a new form in Index.cshtml that posts to the EditDocument action, as shown below.
@{Html.BeginForm("EditDocument", "Home", FormMethod.Get);
{
<div>
<input type="submit" value="Edit Document" style="width:150px;height:27px" />
</div>
}
Html.EndForm();
}Step 5: Include the following namespaces in HomeController.cs.
using System.IO;
using Dropbox.Api;
using Dropbox.Api.Files;
using Syncfusion.Presentation;Step 6: Include the below code snippet in HomeController.cs to open a Presentation from Dropbox Cloud Storage.
public async Task<IActionResult> EditDocument()
{
try
{
//Retrieve the document from Dropbox
MemoryStream stream = await GetDocumentFromDropBox();
//Set the position to the beginning of the MemoryStream
stream.Position = 0;
//Create an instance of PowerPoint Presentation file
using (IPresentation pptxDocument = Presentation.Open(stream))
{
//Get the first slide from the PowerPoint presentation
ISlide slide = pptxDocument.Slides[0];
//Get the first shape of the slide
IShape shape = slide.Shapes[0] as IShape;
//Change the text of the shape
if (shape.TextBody.Text == "Company History")
shape.TextBody.Text = "Company Profile";
//Saving the PowerPoint file to a MemoryStream
MemoryStream outputStream = new MemoryStream();
pptxDocument.Save(outputStream);
//Download the PowerPoint file in the browser
FileStreamResult fileStreamResult = new FileStreamResult(outputStream, "application/powerpoint");
fileStreamResult.FileDownloadName = "EditPowerPoint.pptx";
return fileStreamResult;
}
}
catch (Exception ex)
{
Console.WriteLine($"Error: {ex.Message}");
return Content("Error occurred while processing the file.");
}
}Download file from Dropbox cloud storage
This is the helper method to download a Presentation from Dropbox cloud storage.
/// <summary>
/// Download file from Dropbox cloud storage
/// </summary>
/// <returns></returns>
public async Task<MemoryStream> GetDocumentFromDropBox()
{
//TODO: Replace with your Dropbox access token. In production, read this from configuration or a secret store.
var accessToken = "Access_Token";
//Define the file path in Dropbox where the file is located. For ex: "/Template.pptx" or "/Apps/Template.pptx"
var filePathInDropbox = "/PowerPointTemplate.pptx";
try
{
//Create a new DropboxClient instance using the provided access token
using (var dbx = new DropboxClient(accessToken))
{
//Start a download request for the specified file in Dropbox
using (var response = await dbx.Files.DownloadAsync(filePathInDropbox))
{
//Get the content of the downloaded file as a stream
var content = await response.GetContentAsStreamAsync();
MemoryStream stream = new MemoryStream();
content.CopyTo(stream);
return stream;
}
}
}
catch (Exception ex)
{
Console.WriteLine($"Error retrieving document from Dropbox: {ex.Message}");
throw; // or handle the exception as needed
}
}You can download a complete working sample from GitHub.
By executing the program, you will get the Presentation as follows.
Save Presentation to Dropbox Cloud Storage
Steps to save a Presentation to Dropbox Cloud Storage.
Step 1: Create a new ASP.NET Core Web Application (Model-View-Controller).
Step 2: Name the project.
Step 3: Install the following Nuget packages in your application from NuGet.org.
Step 4: Add a new form in Index.cshtml that posts to the UploadDocument action, as shown below.
@{Html.BeginForm("UploadDocument", "Home", FormMethod.Get);
{
<div>
<input type="submit" value="Upload Document" style="width:150px;height:27px" />
</div>
}
Html.EndForm();
}Step 5: Include the following namespaces in HomeController.cs.
using System.IO;
using Dropbox.Api.Files;
using Dropbox.Api;
using Syncfusion.Drawing;
using Syncfusion.Presentation;Step 6: Include the below code snippet in HomeController.cs to save a Presentation to Dropbox Cloud Storage.
public async Task<IActionResult> UploadDocument()
{
//Create a new instance of PowerPoint Presentation file
using (IPresentation pptxDocument = Presentation.Create())
{
//Add a new slide to file and apply background color
ISlide slide = pptxDocument.Slides.Add(SlideLayoutType.TitleOnly);
//Specify the fill type and fill color for the slide background
slide.Background.Fill.FillType = FillType.Solid;
slide.Background.Fill.SolidFill.Color = ColorObject.FromArgb(232, 241, 229);
//Add title content to the slide by accessing the title placeholder of the TitleOnly layout-slide
IShape titleShape = slide.Shapes[0] as IShape;
titleShape.TextBody.AddParagraph("Company History").HorizontalAlignment = HorizontalAlignmentType.Center;
//Add description content to the slide by adding a new TextBox
IShape descriptionShape = slide.AddTextBox(53.22, 141.73, 874.19, 77.70);
descriptionShape.TextBody.Text = "IMN Solutions PVT LTD is the software company, established in 1987, by George Milton. The company has been listed as the trusted partner for many high-profile organizations since 1988 and got awards for quality products from reputed organizations.";
//Add bullet points to the slide
IShape bulletPointsShape = slide.AddTextBox(53.22, 270, 437.90, 116.32);
//Add a paragraph for a bullet point
IParagraph firstPara = bulletPointsShape.TextBody.AddParagraph("The company acquired the MCY corporation for 20 billion dollars and became the top revenue maker for the year 2015.");
//Format how the bullets should be displayed
firstPara.ListFormat.Type = ListType.Bulleted;
firstPara.LeftIndent = 35;
firstPara.FirstLineIndent = -35;
//Add another paragraph for the next bullet point
IParagraph secondPara = bulletPointsShape.TextBody.AddParagraph("The company is participating in top open source projects in automation industry.");
//Format how the bullets should be displayed
secondPara.ListFormat.Type = ListType.Bulleted;
secondPara.LeftIndent = 35;
secondPara.FirstLineIndent = -35;
//Gets a picture as a stream (Image.jpg is shipped with the GitHub sample under Data/)
using (FileStream pictureStream = new FileStream(Path.GetFullPath("Data/Image.jpg"), FileMode.Open))
{
//Adds the picture to a slide by specifying its size and position.
slide.Shapes.AddPicture(pictureStream, 499.79, 238.59, 364.54, 192.16);
}
//Add an auto-shape to the slide
IShape stampShape = slide.Shapes.AddShape(AutoShapeType.Explosion1, 48.93, 430.71, 104.13, 80.54);
//Format the auto-shape color by setting the fill type and text
stampShape.Fill.FillType = FillType.None;
stampShape.TextBody.AddParagraph("IMN").HorizontalAlignment = HorizontalAlignmentType.Center;
//Saves the PowerPoint to MemoryStream
MemoryStream stream = new MemoryStream();
pptxDocument.Save(stream);
//Reset the stream position so the upload reads from the beginning
stream.Position = 0;
//Upload the document to Dropbox
await UploadDocumentToDropBox(stream);
return Ok("PowerPoint uploaded to Dropbox Cloud Storage.");
}
}Upload file to Dropbox cloud storage
This is the helper method to upload a Presentation to Dropbox cloud storage.
/// <summary>
/// Upload file to Dropbox
/// </summary>
/// <param name="stream">MemoryStream containing the PowerPoint file to upload</param>
public async Task UploadDocumentToDropBox(MemoryStream stream)
{
//TODO: Replace with your Dropbox access token. In production, read this from configuration or a secret store.
var accessToken = "Access_Token";
//Define the file path in Dropbox where the file should be saved. For ex: "/Template.pptx" or "/Apps/Template.pptx"
var filePathInDropbox = "FilePath";
try
{
//Create a new DropboxClient instance using the provided access token
using (var dbx = new DropboxClient(accessToken))
{
//Upload the file to Dropbox, overwriting any existing file at the same path.
//Use WriteMode.Add.Instance instead of Overwrite to receive a conflict if the file already exists.
await dbx.Files.UploadAsync(filePathInDropbox, WriteMode.Overwrite.Instance, body: stream);
}
Console.WriteLine("Upload completed successfully");
}
catch (Exception e)
{
Console.WriteLine("Unknown encountered on server. Message:'{0}' when writing an object", e.Message);
}
}You can download a complete working sample from GitHub.
By executing the program, the resulting PowerPoint file is uploaded to Dropbox and the page returns a success message.
