public static RestApiAuthMgrWinforms winFormsAuthMgr { get; set; }

public static void PrimaryEntryMethod()
{
    // HELP: Define your encryption items prior to instantiating authorization managers
    // You must define your own private application token. This ensures that your login details are not overwritten by someone else.
    string applicationToken = "RallyRestAPISample";
    // You must set a user specific salt for encryption.
    string encryptionKey = "UserSpecificSaltForEncryption";
    // You must define your own encryption routines.
    IEncryptionRoutines encryptionUtilities = new EncryptionUtilities();

    // HELP: Instantiate authorization manager
    winFormsAuthMgr = new RestApiAuthMgrWinforms(applicationToken, encryptionKey, encryptionUtilities);

    // HELP: Configure labels for UI. These are global and used by the authentication manager to build their UI.
    // If this is not called, the default labels will be used. In this sample we are changing a label and the default server URL.
    ApiAuthManager.Configure(loginWindowServerLabelText: "My Updated Server Label", loginWindowDefaultServer: new Uri("http://onprem-url"));

    // HELP: Set the logo that is shown in the login window
    RestApiAuthMgrWinforms.SetLogo(ImageResources.RallyLogo40x40);

    // Help: You can auto-authenticate if you want. We do not have it enabled for this application.
    // winFormsAuthMgr.AutoAuthenticate(true);
}

// HELP: This method shows you how to open a login window.
private void openWinformsLogin_Click(object sender, RoutedEventArgs e)
{
    // HELP: Delegates are provided so we can be notified that authentication or SSO authentication has completed.
    winFormsAuthMgr.ShowUserLoginWindow(AuthenticationComplete, SsoAuthenticationComplete);
}

// HELP: This delegate notifies us that authentication has completed.
private void AuthenticationComplete(RallyRestApi.AuthenticationResult authenticationResult, RallyRestApi api)
{
    UpdateAuthenticationResults(authenticationResult, api);
}

// HELP: This delegate notifies us that SSO authentication has completed.
private void SsoAuthenticationComplete(RallyRestApi.AuthenticationResult authenticationResult, RallyRestApi api)
{
    UpdateAuthenticationResults(authenticationResult, api);
}

// HELP: This method handles the passthrough from the delegates.
// This is where you would need to update your application to show the logged in state.
private void UpdateAuthenticationResults(RallyRestApi.AuthenticationResult authenticationResult, RallyRestApi api)
{
    // Change your applications behavoir based upon the new AuthenticationResult
}