各位好，最近有个需求，需要实现Virtulizing WrapPanel 参照msdn blog上的这篇教程以及MSDN的官方例子,
写了个自定义的Warp Panel, Wrap的功能到时能正常实现,可是就是不能滑动了,调试的时候将断点设置在IScrollInfo里的接口函数里,但是断点怎么也进不去了,所以在此请教一下是哪出问题了,谢谢!
public class VTWrapPanel : VirtualizingPanel, IScrollInfo
{
private TranslateTransform _trans = new TranslateTransform();
public VTWrapPanel()
{
this.RenderTransform = _trans;
}
#region VirtualizingPanel
#region 私有字段
private Size _extent = new Size(0, 0);
private Size _viewport = new Size(0, 0);
#endregion
#region 重载方法
/// <summary>
/// 计算布局
/// </summary>
/// <param name="availableSize"></param>
/// <returns></returns>
protected override Size MeasureOverride(Size availableSize)
{
Size childSize = new Size(
availableSize.Width,
(availableSize.Height * 2) / this.Children.Count);
Size extent = new Size(
availableSize.Width,
childSize.Height * this.Children.Count);
if (extent != _extent)
{
_extent = extent;
if (_owner != null)
_owner.InvalidateScrollInfo();
}
if (availableSize != _viewport)
{
_viewport = availableSize;
if (_owner != null)
_owner.InvalidateScrollInfo();
}
foreach (UIElement child in this.Children)
{
child.Measure(childSize);
}
return availableSize;
}
protected override Size ArrangeOverride(Size finalSize)
{
Size childSize = new Size(
finalSize.Width,
(finalSize.Height * 2) / this.Children.Count);
Size extent = new Size(
finalSize.Width,
childSize.Height * this.Children.Count);
if (extent != _extent)
{
_extent = extent;
if (_owner != null)
_owner.InvalidateScrollInfo();
}
if (finalSize != _viewport)
{
_viewport = finalSize;
if (_owner != null)
_owner.InvalidateScrollInfo();
}
for (int i = 0; i < this.Children.Count; i++)
{
this.Children[i].Arrange(new Rect(0, childSize.Height * i, childSize.Width, childSize.Height));
}
return finalSize;
}
#endregion
#endregion
#region IScrollInfo
#region 私有字段
private ScrollViewer _owner;
private bool _canHScroll = false;
private bool _canVScroll = false;
private Point _offset;
#endregion
#region 公共属性
public ScrollViewer ScrollOwner
{
get { return _owner; }
set { _owner = value; }
}
public bool CanHorizontallyScroll
{
get { return _canHScroll; }
set { _canHScroll = value; }
}
public bool CanVerticallyScroll
{
get { return _canVScroll; }
set { _canVScroll = value; }
}
public double HorizontalOffset
{
get { return _offset.X; }
}
public double VerticalOffset
{
get { return _offset.Y; }
}
public double ExtentHeight
{
get { return _extent.Height; }
}
public double ExtentWidth
{
get { return _extent.Width; }
}
public double ViewportHeight
{
get { return _viewport.Height; }
}
public double ViewportWidth
{
get { return _viewport.Width; }
}
#endregion
#region Scroll commands
public void LineUp()
{
SetVerticalOffset(this.VerticalOffset - 1);
}
public void LineDown()
{
SetVerticalOffset(this.VerticalOffset + 1);
}
public void LineLeft()
{
SetHorizontalOffset(this.HorizontalOffset - 1);
}
public void LineRight()
{
SetHorizontalOffset(this.HorizontalOffset + 1);
}
/// <summary>
/// ensure the visiblity of one of the children in the Panel
/// REF:http://blogs.msdn.com/b/bencon/archive/2006/12/09/iscrollinfo-tutorial-part-iv.aspx
/// </summary>
/// <param name="visual"> the thing that we need to make visible - it will be one of the children of the Panel</param>
/// <param name="rectangle">the rectangle of the Visual that needs to be visible</param>
/// <returns>the rectangle of the Visual that you managed to make visible</returns>
public Rect MakeVisible(UIElement visual, Rect rectangle)
{
for (int i = 0; i < this.Children.Count; i++)
{
if ((UIElement)this.Children[i] == visual)
{
// we found the visual! Let's scroll it into view. First we need to know how big each child is.
Size finalSize = this.RenderSize;
Size childSize = new Size(
finalSize.Width,
(finalSize.Height * 2) / this.Children.Count);
// now we can calculate the vertical offset that we need and set it
SetVerticalOffset(childSize.Height * i);
// child size is always smaller than viewport, because that is what makes the Panel
return rectangle;
}
}
throw new ArgumentException("Given visual is not in this Panel");
}
public void MouseWheelDown()
{
throw new NotImplementedException();
}
public void MouseWheelLeft()
{
throw new NotImplementedException();
}
public void MouseWheelRight()
{
throw new NotImplementedException();
}
public void MouseWheelUp()
{
throw new NotImplementedException();
}
public void PageDown()
{
throw new NotImplementedException();
}
public void PageLeft()
{
throw new NotImplementedException();
}
public void PageRight()
{
throw new NotImplementedException();
}
public void PageUp()
{
throw new NotImplementedException();
}
#endregion
public void SetHorizontalOffset(double offset)
{
//首先检查offset是不是小于0，或者是否大于比当前的宽度，如果是的话，将其置为0
if (offset < 0 || _viewport.Width >= _extent.Width)
{
offset = 0;
}
else
{
if (offset + _viewport.Width >= _extent.Width)
{
offset = _extent.Width - _viewport.Width;
}
}
_offset.X = offset;
if (_owner != null)
_owner.InvalidateScrollInfo();
_trans.X = -offset;
}
public void SetVerticalOffset(double offset)
{
if (offset < 0 || _viewport.Height >= _extent.Height)
{
offset = 0;
}
else
{
if (offset + _viewport.Height >= _extent.Height)
{
offset = _extent.Height - _viewport.Height;
}
}
_offset.Y = offset;
if (_owner != null)
_owner.InvalidateScrollInfo();
_trans.Y = -offset;
}
#endregion
}
