/// <summary>
/// When the expander expands, need to put the error message in the
/// adorner layer because the controls below it, may have their own
/// adorner validation error messages, this places the expander
/// popup on top of all other adorder layer elements.
/// </summary>
void _objErrorsExpander_Expanded(object sender, RoutedEventArgs e)
{
//this forces the ErrorMessage to be reread from it's source
this.InvalidateProperty(ErrorMessageProperty);
var expanderGrid = VisualTreeSearchAssistant.FindVisualChild <Grid>(_errorsExpander);
_errorsExpanderAdornerLayer = AdornerLayer.GetAdornerLayer(expanderGrid);
String[] delimiter = { Environment.NewLine };
String[] errorMessages = this.ErrorMessage.Split(delimiter, StringSplitOptions.RemoveEmptyEntries);
Array.Sort(errorMessages);
var txt = new TextBlock {
Width = this.Width, TextWrapping = TextWrapping.Wrap, Text = string.Join(Environment.NewLine + Environment.NewLine, errorMessages), Padding = new Thickness(5), Foreground = this.ErrorPopUpForeground, Background = this.ErrorPopUpBackground, Effect = new System.Windows.Media.Effects.DropShadowEffect {
ShadowDepth = 2
}
};
//need to move the TextBlock down below the expander and indent a little
var obj = new TranslateTransform(5, _errorsExpander.ActualHeight + 2);
txt.RenderTransform = obj;
_textBlockAdorner = new TextBlockAdorner(expanderGrid, txt);
_textBlockAdorner.MouseLeave -= _objTextBlockAdorner_MouseLeave;
_textBlockAdorner.MouseEnter -= _objTextBlockAdorner_MouseEnter;
_errorsExpanderAdornerLayer.Add(_textBlockAdorner);
}
/// <summary>
/// When the expander collapses, need to remove the TextBlock adorner
/// </summary>
void _objErrorsExpander_Collapsed(object sender, RoutedEventArgs e)
{
if (_errorsExpanderAdornerLayer != null)
{
_textBlockAdorner.MouseLeave -= _objTextBlockAdorner_MouseLeave;
_textBlockAdorner.MouseEnter -= _objTextBlockAdorner_MouseEnter;
_errorsExpanderAdornerLayer.Remove(_textBlockAdorner);
_textBlockAdorner = null;
_errorsExpanderAdornerLayer = null;
}
}