app.xml.cs の OnLaunched メソッドに以下のコードがありますが、ダイアログがまったく表示されません。
CredentialPickerOptions credPickerOptions = new CredentialPickerOptions();
credPickerOptions.Message = Message.Text;
credPickerOptions.Caption = Caption.Text;
credPickerOptions.TargetName = Target.Text;
credPickerOptions.AlwaysDisplayDialog = (AlwaysShowDialog.IsChecked == true);
CredentialPickerOptions options = new CredentialPickerOptions()
{
AuthenticationProtocol = AuthenticationProtocol.Basic,
CredentialSaveOption = Windows.Security.Credentials.UI.CredentialSaveOption.Selected,
CallerSavesCredential = true,
Caption = "Basic Login",
Message = "Please enter your credentials",
TargetName = "."
};
CredentialPickerResults results = await CredentialPicker.PickAsync(options);