IConverter C＃，wpf，checkbox.Checked

Question

XAML Code

<TreeView.Resources>
  <local:BoolToVisibleOrHidden x:Key="BoolToVisConverter" Collapse="True"/>
</TreeView.Resources>
<TreeViewItem Header="First Child" Name="_firstChild"  
  Visibility="{Binding Path=VisibleOnCheck, Mode=OneWay, NotifyOnTargetUpdated=True, Converter={StaticResource BoolToVisConverter}}" />
 <CheckBox Name="_checkBoxvisible" IsChecked="{Binding Path= VisibleOnCheck, Mode=TwoWay}" Content="show" Checked="CheckBox />

CheckBox Checked

private void CheckBox(object sender, RoutedEventArgs e)
{
  if (MessageBox.Show("", "", MessageBoxButton.YesNo) == 
    System.Windows.Forms.DialogResult.Yes)
  {   
    VisibleOnCheck = true;
  } 
  else
  {
    VisibleOnCheck = false; 
  }
}

MODEL CODE

Private bool __visible;
public bool VisibleOnCheck
{
    get { return _ visible; }
    set { _visible = value; OnPropertyChanged("VisibleOnCheck "); }
}

public class BoolToVisibleOrHidden : IValueConverter
{
    #region Constructors

    public BoolToVisibleOrHidden() { }
    #endregion

    #region Propertie Collapse

    public bool Collapse { get; set; }
    public bool Reverse { get; set; }

    #endregion

    #region IValueConverter Members

    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        bool bValue = (bool)value;

            if (bValue != Reverse)
            {
                return Visibility.Visible;
            }
            else
            {
                if (Collapse)
                    return Visibility.Collapsed;
                else
                    return Visibility.Hidden;
            }
    }

    public object ConvertBack(object value, Type targetType, object parameter,
                              System.Globalization.CultureInfo culture)
    {
        Visibility visibility = (Visibility) value;

        if (visibility == Visibility.Visible)
            return !Reverse;
        else
            return Reverse;
    }

    #endregion
    }

I want ,Treeview item header should visible when MessageBox .Yes clicked, but here its visible's MessageBox and TreeviewItem same time without clicking Messagebox.yes, can any one help please.

Answer 1

You have a TwoWay binding on the CheckBox to VisibleOnCheck , so if you check the Checkbox its going to toggle the Visibility on the TreeViewItem .

If you want to handle the VisibleOnCheck in the Checked event handler based on the DialogResult you will have to remove the TwoWay binding or the binding altogether.

<CheckBox Name="_checkBoxvisible" Content="show" Checked="CheckBox />

I would also suggest using the WPF MessageBox over the Winforms one, seems a bit odd to drag in another framework for a MessageBox .

private void CheckBox(object sender, RoutedEventArgs e)
{
   VisibleOnCheck = MessageBox.Show("","", MessageBoxButton.YesNo) == MessageBoxResult.Yes;
} 

---

Edit

Since the problem is due to both controls binding to VisibleOnCheck you could just bind the TreeViewItem Visibility directly to the Checkbox in the Xaml

<TextBlock Text="TreeViewItem" Visibility="{Binding IsChecked, ElementName=chkbx, Converter={StaticResource BooleanToVisibilityConverter}}" />
<CheckBox x:Name="chkbx" Content="CheckBox" Checked="Checked"   />

and in the event just set the IsChecked based on your Dialog result

private void Checked(object sender, RoutedEventArgs e)
{
     (sender as CheckBox).IsChecked = MessageBox.Show("","", MessageBoxButton.YesNo) == MessageBoxResult.Yes;
}