OAuth is an open standard to authorize application to access user data from online servers without sharing user's credentials. It is specifically designed to work in 'Hypertext Transfer Protocol (HTTP)'. OAuth provides 'access tokens' to applications when the user gives approval, and through this access token the application can access the user's data in online servers.
In this tutorial we will explain how to make your own app which can read a person's Yahoo contacts. In a common language the app will be a Yahoo Contact Reader for anyone who authorizes it to use it. We will use C# to communicate with Yahoo API's and our app is made in ASP.NET platform.
In this tutorial we will develop a web app to get all Google contacts from a person account that authorizes the app. We will develop our app in asp.net platform and will use C# to communicate with Google Contacts API. Follow the steps as outlined in this tutorial.