I finalized a backup program (now using DotNetZip). During collecting the files, adding them to the zip and saving the zip file, the program issues progress information in 3 different WPF TextBlocks. I centralized the actual assignment in a method. Also there are some status updates in between.
Originally I had a mix of MvvM and directly assigning a value to a control using it's name. I decided to use MvvM all over, checked all the "bells & whistles" like get/set/RaisePropertyChanged("Name") and public partial class MainWindow : Window, INotifyPropertyChanged. Plus
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TextBlock x:Name="ProgressText" Text="{Binding Progress, UpdateSourceTrigger=PropertyChanged}"In my general method I have this code:
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public void ShowMessage(string cMessage,string cCtrl,bool lUpdateUI)
this.Dispatcher.Invoke(() =>
{
//ProgressText.Text=cMessage;
Progress=cMessage;
});Now what happens is that some of the messages are not updated in the UI (while I do not see the difference, processs wise). That comes expected, and by calling ExtensionMethods.ProcessUITasks(), a not recommended (why not?) but great working C# equivalent of VO's ApplicationExecWhileEvent I can fix this.
But my question is: updating also does not work on more or less the same places when I use MvvM. And I can also fix that with ProcessUITasks!
I thought that one of the advantages of MvvM would be that Windows takes care of UI updating. But it works more or less the same as directly updating the TextBlock and it needs a forced UI update just as much.
Not sure what advantages remain using MvvM except some academic, like separating program logic and UI, which has no value in a program like this. Or do I miss something?
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public static void ProcessUITasks()
// From http://stackoverflow.com/questions/8128670/force-redraw-before-long-running-operations
// When called, forces the UI to redraw. It is however not recommended
{
DispatcherFrame frame = new DispatcherFrame();
Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, new DispatcherOperationCallback(delegate (object parameter)
{
frame.Continue = false;
return null;
}), null);
Dispatcher.PushFrame(frame);
}// ProcessUITasks
