File uploading Dropbox v2.0 API

Question

I'm using the new Dropbox SDK v2 for .NET.

I'm trying to upload a document to a Dropbox account.

public async Task UploadDoc()
    {
        using (var dbx = new DropboxClient("XXXXXXXXXX"))
        {
            var full = await dbx.Users.GetCurrentAccountAsync();
            await Upload(dbx, @"/MyApp/test", "test.txt","Testing!");
        }
    }
async Task Upload(DropboxClient dbx, string folder, string file, string content)
    {
        using (var mem = new MemoryStream(Encoding.UTF8.GetBytes(content)))
        {
            var updated = await dbx.Files.UploadAsync(
                folder + "/" + file,
                WriteMode.Overwrite.Instance,
                body: mem);

            Console.WriteLine("Saved {0}/{1} rev {2}", folder, file, updated.Rev);
        }
    }

This code snippet actually creates a test.txt document on the Dropbox account with the "Testing!" content, but I want to upload a document, with a given path (for example: "C:\MyDocuments\test.txt"), is that possible?

Any help would be very much appreciated.

Answer 1

The UploadAsync method will use whatever data you pass to the body parameter as the uploaded file content.

If you want to upload the contents of a local file, you'll need to give it a stream for that file.

There's an example here that shows how to use this method to upload a local file (including logic for handling large files):

This example uses the Dropbox .NET library to upload a file to a Dropbox account, using upload sessions for larger files:

private async Task Upload(string localPath, string remotePath)
{
    const int ChunkSize = 4096 * 1024;
    using (var fileStream = File.Open(localPath, FileMode.Open))
    {
        if (fileStream.Length <= ChunkSize)
        {
            await this.client.Files.UploadAsync(remotePath, body: fileStream);
        }
        else
        {
            await this.ChunkUpload(remotePath, fileStream, (int)ChunkSize);
        }
    }
}

private async Task ChunkUpload(String path, FileStream stream, int chunkSize)
{
    ulong numChunks = (ulong)Math.Ceiling((double)stream.Length / chunkSize);
    byte[] buffer = new byte[chunkSize];
    string sessionId = null;
    for (ulong idx = 0; idx < numChunks; idx++)
    {
        var byteRead = stream.Read(buffer, 0, chunkSize);

        using (var memStream = new MemoryStream(buffer, 0, byteRead))
        {
            if (idx == 0)
            {
                var result = await this.client.Files.UploadSessionStartAsync(false, memStream);
                sessionId = result.SessionId;
            }
            else
            {
                var cursor = new UploadSessionCursor(sessionId, (ulong)chunkSize * idx);

                if (idx == numChunks - 1)
                {
                    FileMetadata fileMetadata = await this.client.Files.UploadSessionFinishAsync(cursor, new CommitInfo(path), memStream);
                    Console.WriteLine (fileMetadata.PathDisplay);
                }
                else
                {
                    await this.client.Files.UploadSessionAppendV2Async(cursor, false, memStream);
                }
            }
        }
    }
}

Answer 2

You can use the following method if you just want to upload a file with a given path:

private async Task Upload(DropboxClient dbx, string folder, string file, string fileToUpload)
    {
        using (var mem = new MemoryStream(File.ReadAllBytes(fileToUpload)))
        {
            var updated = await dbx.Files.UploadAsync(
                folder + "/" + file,
                WriteMode.Overwrite.Instance,
                body: mem);
            Console.WriteLine("Saved {0}/{1} rev {2}", folder, file, updated.Rev);
        }
    }

Parameter example:

folder = "/YourDropboxFolderName";
file = "fileName.pdf";
fileToUpload = @"C:\Users\YourUserName\fileName.pdf";