How to upload to Google Drive API from memory with C# 4

Google drive API standard examples.

Most of if not all of the upload samples and examples for the Google drive api refer to it as file upload data. This implies that you have a file on your disk that you wish to upload. Even all of my own How to upload a file to Google Drive with C# .net. This then leads you to wonder what would happen if the data you wish to upload isn’t actually on your disk. What if its in memory?

What if the data isn’t in a file?

Lets consider this for a moment. What if your system generates invoices. You build up the invoice and its all stored within a variable within your application. Now you want to upload the invoice to Google drive for storage, this is probably a bad example as you would probably want to store them in the database.

Now if we look at all the upload samples for the Google drive api they are going to make you think that you will first need to save the file to disk before creating a file stream to upload it to Google drive. The fact of the matter is you dont have to. You can upload a memory stream as well.

var uploadString = "Test";
var fileName = "ploadFileString.txt";
// Upload file Metadata
var fileMetadata = new Google.Apis.Drive.v3.Data.File()
    {
     Name = fileName,
     Parents = new List<string>() { "1R_QjyKyvET838G6loFSRu27C-3ASMJJa" }  // folder to upload the file to
     };

var fsSource = new MemoryStream(Encoding.UTF8.GetBytes(uploadString ?? ""));

string uploadedFileId;
            
// Create a new file, with metadata and stream.
var request = service.Files.Create(fileMetadata, fsSource, "text/plain");
request.Fields = "*";
var results = await request.UploadAsync(CancellationToken.None);

if (results.Status == UploadStatus.Failed)
   {
   Console.WriteLine($"Error uploading file: {results.Exception.Message}");
   }
// the file id of the new file we created
uploadedFileId = request.ResponseBody?.Id;

In the above code I have a string variable called uploadString this variable is storing some text that I wish to upload to google drive to a text file called fileName. The key part of this code is where I concert the uploadString to a memory stream. Normally we would create a File Steam if we are reading the file from disk.

Conclusion

You can use any type of stream to upload the file to Google drive api. Normally we think of uploading Files so we would use a file stream reading all the file data into the stream and then uploading it. However if is possible that the data may already reside within your application in memory in which case you can just upload the data as a memory stream.

I would like to take the time to thank user Richard on stack overflow for asking this question How to save a file to Google Drive from Flutter web without a local file on disk? The question was related to Flutter but I was intrigued as it was not something I tried before. Works like a charm.