滚动条滑到底完美解决方案(适合任何带滚动条或ScrollBar控件 (二)

2014-11-24 02:32:53 · 作者: · 浏览: 10
.ScrollableHeight < double.Epsilon || Scroll.VerticalOffset > double.Epsilon)
return;
}
break;
case DirectionType.Bottom:
{
if (Scroll.ScrollableHeight < double.Epsilon || Scroll.VerticalOffset + Scroll.ExtentHeight - Scroll.ScrollableHeight < Scroll.ScrollableHeight)
return;
}
break;
case DirectionType.Left:
{
if (Scroll.ScrollableWidth < double.Epsilon || Scroll.HorizontalOffset > double.Epsilon)
return;
}
break;
case DirectionType.Right:
{
if (Scroll.ScrollableWidth < double.Epsilon || Scroll.HorizontalOffset < Scroll.ScrollableWidth)
return;
}
break;
default: break;
}

if (ScrollTrigger != null)
{
ScrollTrigger(this.AssociatedObject, new EventArgs());
}
base.InvokeActions(null);

}


protected override void OnDetaching()
{
base.OnDetaching();
}
}

public class ScrollViewerTrigger:TriggerBase
{
ScrollViewer ScrollView;
public static readonly DependencyProperty DirectionTypeProperty = DependencyProperty.Register("DirectionType", typeof(DirectionType), typeof(ScrollViewerTrigger), new PropertyMetadata(DirectionType.Bottom));

public DirectionType DirectionType
{
get
{
return (DirectionType)base.GetValue(ScrollViewerTrigger.DirectionTypeProperty);
}
set
{
base.SetValue(ScrollViewerTrigger.DirectionTypeProperty, value);
}
}

public event EventHandler ScrollTrigger;

public static readonly DependencyProperty VerticalOffsetProperty = DependencyProperty.Register("VerticalOffset", typeof(double), typeof(ScrollViewerTrigger), new PropertyMetadata(0.0, new PropertyChangedCallback(VerticalOffsetPropertyChanged)));

public double VerticalOffset
{
get
{
return (double)base.GetValue(ScrollViewerTrigger.VerticalOffsetProperty);
}
set
{
base.SetValue(ScrollViewerTrigger.VerticalOffsetProperty, value);
}

}

public static void VerticalOffsetPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var behavior = d as ScrollViewerTrigger;
if (behavior != null)
behavior.OnVerticalOffsetChanged();
}

protected override void OnAttached()
{
base.OnAttached();

if (this.AssociatedObject != null && this.AssociatedObject is FrameworkElement)
{
(this.AssociatedObject as FrameworkElement).SizeChanged += control_SizeChanged;
}
}

void control_SizeChanged(object sender, SizeChangedEventArgs e)
{
if (this.AssociatedObject == null || !(this.AssociatedObject is FrameworkElement))
return;

ScrollViewer Scroll = this.AssociatedObject.GetFirstDescendantOfType();
if (Sc