Why Isn't My Dispatcher Displaying my Status Message? - wpf

Question

I am trying to display a status message when the delete operation starts, something like Deleting Items... so the user knows what's going on. I have a DeleteManager class that handles the display of messages when deleting any POCO:
public class DeleteManager : IDisposable
{
private readonly IStatusMessageService _status;
private readonly string _objectInstanceName;
private readonly string _objectTypeName;
private readonly string _singularFormat = "Are you sure you want to delete this {0}?";
private readonly string _pluralFormat = "Are you sure you want to delete these {0}?";
public readonly bool Confirmed;
private bool _multipleItems;
private readonly Dispatcher _dispatcher;
/// <summary>
/// Displays status messages and performs confirmation for deleting an object
/// </summary>
/// <param name="status">the instance of IStatusMessageService that will display messages</param>
/// <param name="objectInstanceName">The name of the instance of the object to delete</param>
/// <param name="objectTypeName">The type of object to delete - specify the plural if needed. </param>
/// <param name="multipleItems">Whether or not there are multiple items, to use plural strings.</param>
public DeleteManager(IStatusMessageService status, string objectTypeName, string objectInstanceName = null, bool multipleItems = false)
{
_dispatcher = Wpf.Application.Current.Dispatcher;
_status = status;
_objectInstanceName = objectInstanceName;
_objectTypeName = objectTypeName;
_multipleItems = multipleItems;
Confirmed = ConfirmDelete();
if (Confirmed)
{
var message = _multipleItems
? string.Format("Deleting multiple {0}...", _objectTypeName)
: string.Format("Deleting {0}: {1}...", _objectTypeName, _objectInstanceName);
// this is the message that doesn't display... dunno why
_dispatcher.BeginInvoke(new Action(() => _status.Status.StaticMessage(message)));
}
}
private bool ConfirmDelete()
{
var format = _multipleItems
? _pluralFormat
: _singularFormat;
var message = string.Format(format, (_objectInstanceName == null)
? _objectTypeName
: string.Format("{0} : \"{1}\"", _objectTypeName, _objectInstanceName));
return (bool)_dispatcher.Invoke(
new Func<bool>(() =>
// StatusControl is a modal window
StatusControl.ConfirmMessage("Delete Warning", message)));
}
public void Dispose()
{
if (Confirmed)
{
var message = _multipleItems
? string.Format("Multipe {0} Deleted.", _objectTypeName)
: string.Format("{0} Deleted: {1}.", _objectTypeName, _objectInstanceName);
// THIS message displays just fine.
_dispatcher.BeginInvoke(new Action(() => _status.Status.InfoMessage(message)));
}
}
}
... and it's being used like this:
var deleteId = Poco.Id;
using (var delete = new DeleteManager(StatusMessageService, "Poco", Poco.Name))
{
if (delete.Confirmed)
{
var success = _dataProvider.DeleteCurriculum(deleteId);
if (success)
{ EventAggregator.GetEvent<DeletedNotification>().Publish(deleteId); }
}
}
The InfoMessage() call in Dispose() displays just fine, but the StaticMessage() call in the constructor never displays... even if I change it to use InfoMessage() instead... I cannot determine why, nor how to fix it.