//The State should be called before any await key word to avoid the system.InvalidOperationException: You can only use State between OnNavigatedTo and OnNavigatedFrom Exception
//http://blog.ariankulp.com/2014/04/you-can-only-use-state-between.html
protected override async void OnNavigatedTo(NavigationEventArgs e)
{
progressIndicator = RetrieveProgressIndicator();
loadingPanel = RetrieveLoadingContainer();
if (isManagingProgressIndicatorItself == false)
{
progressIndicator.IsVisible = true;
if(loadingPanel != null && displayLoaderPanelNextTime == true)
{
loadingPanel.Visibility = Visibility.Visible;
}
}
SendPage();
mainContener = RetrieveMainContainer();
connectivityContainer = RetrieveConnectivityContainer();
LoadQueryString();
try
{
if (viewModel == null && isMVVMUsed == true)
{
if (State.ContainsKey(M4MPhoneApplicationPage.VIEW_MODEL_KEY) == true)
{
viewModel = State[M4MPhoneApplicationPage.VIEW_MODEL_KEY] as M4MBaseViewModel;
}
else
{
viewModel = await ComputeViewModel();
}
}
}
catch (M4MConnectivityException exception)
{
OnDisplayConnectivityLayout();
throw new M4MConnectivityException(exception);
}
OnFullfillDisplayObjects();
if (connectivityContainer != null)
{
connectivityContainer.Visibility = Visibility.Collapsed;
}
if (mainContener != null)
{
mainContener.Visibility = Visibility.Visible;
}
if (isManagingProgressIndicatorItself == false)
{
progressIndicator.IsVisible = false;
if(loadingPanel != null)
{
loadingPanel.Visibility = Visibility.Collapsed;
}
}
base.OnNavigatedTo(e);
}
/// <summary>
/// Invokes this method when you want to reload the business objects, from memory, local persistence, via web services, necessary for the entity processing.
/// </summary>
/// <returns></returns>
protected async Task Refresh()
{
if (isManagingProgressIndicatorItself == false)
{
progressIndicator.IsVisible = true;
if(loadingPanel != null && displayLoaderPanelNextTime == true)
{
if (connectivityContainer != null)
{
connectivityContainer.Visibility = Visibility.Collapsed;
}
mainContener.Visibility = Visibility.Collapsed;
loadingPanel.Visibility = Visibility.Visible;
}
}
if (viewModel == null)
{
try
{
viewModel = await ComputeViewModel();
}
catch (M4MConnectivityException exception)
{
OnDisplayConnectivityLayout();
throw new M4MConnectivityException(exception);
}
OnFullfillDisplayObjects();
if (connectivityContainer != null)
{
connectivityContainer.Visibility = Visibility.Collapsed;
}
if (isManagingProgressIndicatorItself == false)
{
progressIndicator.IsVisible = false;
if(loadingPanel != null)
{
loadingPanel.Visibility = Visibility.Collapsed;
}
}
if (mainContener != null)
{
mainContener.Visibility = Visibility.Visible;
}
}
else
{
try
{
await RefreshViewModel();
}
catch (M4MConnectivityException exception)
{
if (isManagingProgressIndicatorItself == false)
{
progressIndicator.IsVisible = false;
if(displayLoaderPanelNextTime == true)
{
OnDisplayConnectivityLayout();
}
}
throw new M4MConnectivityException(exception);
}
}
if (isManagingProgressIndicatorItself == false)
{
progressIndicator.IsVisible = false;
if (loadingPanel != null)
{
loadingPanel.Visibility = Visibility.Collapsed;
}
}
if (mainContener != null)
{
mainContener.Visibility = Visibility.Visible;
}
}
