Once you have particular Microsoft Graph message, you can e.g. pass it to a method as parameter. Then you need to make another request to get attachments by message Id, iterate through attachments and cast it to FileAttachment
to get access to the ContentBytes
property and finally save this byte array to the file.
private static async Task SaveAttachments(Message message)
{
var attachments =
await _client.Me.MailFolders.Inbox.Messages[message.Id].Attachments.Request().GetAsync();
foreach (var attachment in attachments.CurrentPage)
{
if (attachment.GetType() == typeof(FileAttachment))
{
var item = (FileAttachment)attachment;
var folder = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
var filePath = Path.Combine(folder, item.Name);
System.IO.File.WriteAllBytes(filePath, item.ContentBytes);
}
}
}