Xamarin Android Code for Office 365 API

GetContacts

async void GetContacts()
{
    DiscoveryClient discoveryClient = new DiscoveryClient(discoveryServiceEndpointUri,
        () =>
        {
            var authResult = authContext.AcquireTokenSilentSync(discoveryServiceResourceId, ClientId, AadUserInfo.UserId);

            return authResult.AccessToken;
        });

    var dcr = await discoveryClient.DiscoverCapabilityAsync("Contacts");

    OutlookServicesClient outlookContactsClient = new OutlookServicesClient(dcr.ServiceEndpointUri,
        async () =>
        {
            var authResult = authContext.AcquireTokenSilentSync(dcr.ServiceResourceId, ClientId, AadUserInfo.UserId);

            return await Task.FromResult<string>(authResult.AccessToken);
        });

    var c = await outlookContactsClient.Me.Contacts.ExecuteAsync();
    var cs = c.CurrentPage;
    foreach (var ci in cs)
    {
                
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.SetMessage(ci.DisplayName);
        builder.SetTitle("Contact");
        builder.SetCancelable(false);
        builder.SetPositiveButton("OK", (sender, args) => { });
        builder.Create().Show();
    }

    if(AadUserInfo == null)
    {
        AadUserInfo = new UserInfo();
    }
}