Control does not refresh after CanExecute-Result does change
c#, commandbinding, wpf
Solution
Ok, I found out myself.
canSaveXML = true;
CommandManager.InvalidateRequerySuggested();
was code inside a background worker. Not good. You have to tell the dispatcher of the window to invoke CommandManager.InvalidateRequerySuggested();
Problem
in my window I have buttons for load and save methods. I use CommandBinding and the save-button has a CanExecute property to keep the user from saving the data before it is loaded. The CanExecute-Methode is connected to a simple bool value called "canSaveXML" ``` private void Save_CanExecute(object sender, CanExecuteRoutedEventArgs e) { if (canSaveXML == false) { e.CanExecute = false; } else { e.CanExecute = true; } e.Handled = true; } ``` My intention is to set canSaveXML = true after the data was loaded but the control does not refresh after the value did change. I did some reading and found out I have to call CommandManager.InvalidateRequerySuggested. I do that now and my code looks like this. ``` canSaveXML = true; CommandManager.InvalidateRequerySuggested(); ``` But the control (button) still does not refresh. I still is disabled untill I trigger anything on the UI or minimixe/maximize the window. After I did that the button is enabled. What is wrong here? In a MSDN sample CommandManager.InvalidateRequerySuggested is called with a dispatchertimer again and again but I refuse to believe that would be the only solution.