Microsoft Graph - Saving file attachments through C#?

Question

Is it possible to save file attachments in C# through Microsoft Graph API?

I know I can get the properties of the attachment (https://developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/api/attachment_get) - can we also save it to a certain location?

Answer 1

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; // Cast from Attachment
            var folder = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
            var filePath = Path.Combine(folder, item.Name);
            System.IO.File.WriteAllBytes(filePath, item.ContentBytes);
        }
    }
}