OAuth is open standard for authorization of authority. It’s important point of OAuth that authority is specified by contents provider, and it’s represent as the Scope.
A client app asserts two authority, one is that identity is correct, and another is that how any scope of information the identity can access.
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OAuth is almost background process of an app also includes a loop of the dialog which is input account and password by user. So developers put a button control which call OAuth on a XAML file, and aquire response then relate the process to appropriate process.
The AuthLauncher_Click handler processes in the code behind defines three processes.
The first is aquire the value of the FlipView which is selected by user. After that, specify identity provider that user selected.
The second is throwing request to identity provider selected by user, it using fixed value as Facebook in sample code.
The last one is aquire first response which represent that identity is correct then pull the token value and throw with it as second request which aquires an information of user on Facebook.
If Facebook app has created, this sample works well.