Getting previews and thumbnails

Notes:

• Thumbnails are available on for files with the following file extensions: "jpg", "jpeg", "png", "tiff", "tif", "gif", and "bmp".
• Photos that are larger than 20MB in size won't be converted to a thumbnail.
• Previews are only generated for files with the following extensions: .doc, .docx, .docm, .ppt, .pps, .ppsx, .ppsm, .pptx, .pptm, .xls, .xlsx, .xlsm, .rtf, .pdf

The library doesn't make any assumption when performing calls to ThumbnailsAsync and PreviewsAsync - it just makes the call to the Dropbox API. It is your responsibility to either make sure the file support thumbnails/previews, or handle the expected exception.

// Create you client object
var options = new Options
    {
        ClientId = "...",
        ClientSecret = "...",
        RedirectUri = "...",

        AccessToken = "..."
    };

var client = new Client(options);

// Make the PreviewsAsync / ThumbnailsAsync call
var preview = await client.Core.Metadata.PreviewsAsync(path);

// Save the returned Stream to a file. Make sure to dispose the Stream afterwards
using (preview.Content)
using (var fs = File.OpenWrite(filename))
{
    await preview.Content.CopyToAsync(fs);
}