Pergunta

These two methods don't seem to be called anywhere. Are they needed in order to use attached behaviors or are they just conveniences to get the property?

public static bool GetIsBroughtIntoViewWhenSelected(TreeViewItem treeViewItem)
{
    return (bool)treeViewItem.GetValue(IsBroughtIntoViewWhenSelectedProperty);
}

public static void SetIsBroughtIntoViewWhenSelected(
  TreeViewItem treeViewItem, bool value)
{
    treeViewItem.SetValue(IsBroughtIntoViewWhenSelectedProperty, value);
}

Full Code from Example at http://www.codeproject.com/Articles/28959/Introduction-to-Attached-Behaviors-in-WPF

public static class TreeViewItemBehavior
{
    #region IsBroughtIntoViewWhenSelected

    public static bool GetIsBroughtIntoViewWhenSelected(TreeViewItem treeViewItem)
    {
        return (bool)treeViewItem.GetValue(IsBroughtIntoViewWhenSelectedProperty);
    }

    public static void SetIsBroughtIntoViewWhenSelected(
      TreeViewItem treeViewItem, bool value)
    {
        treeViewItem.SetValue(IsBroughtIntoViewWhenSelectedProperty, value);
    }

    public static readonly DependencyProperty IsBroughtIntoViewWhenSelectedProperty =
        DependencyProperty.RegisterAttached(
        "IsBroughtIntoViewWhenSelected",
        typeof(bool),
        typeof(TreeViewItemBehavior),
        new UIPropertyMetadata(false, OnIsBroughtIntoViewWhenSelectedChanged));

    static void OnIsBroughtIntoViewWhenSelectedChanged(
      DependencyObject depObj, DependencyPropertyChangedEventArgs e)
    {
        TreeViewItem item = depObj as TreeViewItem;
        if (item == null)
            return;

        if (e.NewValue is bool == false)
            return;

        if ((bool)e.NewValue)
            item.Selected += OnTreeViewItemSelected;
        else
            item.Selected -= OnTreeViewItemSelected;
    }

    static void OnTreeViewItemSelected(object sender, RoutedEventArgs e)
    {
        // Only react to the Selected event raised by the TreeViewItem
        // whose IsSelected property was modified. Ignore all ancestors
        // who are merely reporting that a descendant's Selected fired.
        if (!Object.ReferenceEquals(sender, e.OriginalSource))
            return;

        TreeViewItem item = e.OriginalSource as TreeViewItem;
        if (item != null)
            item.BringIntoView();
    }

    #endregion // IsBroughtIntoViewWhenSelected
Foi útil?

Solução

No; they aren't required.

Those are simply convenience methods for interacting with the property from C# code; if you don't need to, there is no need to write them.

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