In this post, I describe how to authenticate to OneDrive using any Azure AD account or personal Microsoft account and upload and download files. At the end of this post, you will have an understanding of how to leverage Azure, Microsoft Identity, the Microsoft Graph API, and OneDrive for storage in your application. This post requires a Microsoft account and OneDrive subscription. The free one will work. It also requires an Azure subscription with permissions to modify Active Directory. I have not been charged yet with this example but Azure costs may apply depending on usage.

In this post, I examine a WPF application to play mp3 music. I will show how WPF can utilize the MVVM pattern to make code more testable. At the end of this post, you will have an understanding of the MVVM pattern and how to apply it to a WPF application with unit tests. The application is written in .NET core 3.1 and Visual Studio 2019.