备份一个支持虚拟化的wrappanel
2024-08-31 23:39:52
public class VirtualizingWrapPanel : VirtualizingPanel, IScrollInfo
{ #region Fields UIElementCollection _children;
ItemsControl _itemsControl;
IItemContainerGenerator _generator;
private Point _offset = new Point(, );
private Size _extent = new Size(, );
private Size _viewport = new Size(, );
private int firstIndex=;
private Size childSize;
private Size _pixelMeasuredViewport = new Size(, );
Dictionary<UIElement, Rect> _realizedChildLayout = new Dictionary<UIElement, Rect>();
WrapPanelAbstraction _abstractPanel; #endregion #region Properties private Size ChildSlotSize
{
get
{
return new Size(ItemWidth, ItemHeight);
}
} #endregion #region Dependency Properties [TypeConverter(typeof(LengthConverter))]
public double ItemHeight
{
get
{
return (double)base.GetValue(ItemHeightProperty);
}
set
{
base.SetValue(ItemHeightProperty, value);
}
} [TypeConverter(typeof(LengthConverter))]
public double ItemWidth
{
get
{
return (double)base.GetValue(ItemWidthProperty);
}
set
{
base.SetValue(ItemWidthProperty, value);
}
} public Orientation Orientation
{
get { return (Orientation)GetValue(OrientationProperty); }
set { SetValue(OrientationProperty, value); }
} public static readonly DependencyProperty ItemHeightProperty = DependencyProperty.Register("ItemHeight", typeof(double), typeof(VirtualizingWrapPanel), new FrameworkPropertyMetadata(double.PositiveInfinity));
public static readonly DependencyProperty ItemWidthProperty = DependencyProperty.Register("ItemWidth", typeof(double), typeof(VirtualizingWrapPanel), new FrameworkPropertyMetadata(double.PositiveInfinity));
public static readonly DependencyProperty OrientationProperty = StackPanel.OrientationProperty.AddOwner(typeof(VirtualizingWrapPanel), new FrameworkPropertyMetadata(Orientation.Horizontal)); #endregion #region Methods public void SetFirstRowViewItemIndex(int index)
{
SetVerticalOffset((index) / Math.Floor((_viewport.Width) / childSize.Width));
SetHorizontalOffset((index) / Math.Floor((_viewport.Height) / childSize.Height));
} private void Resizing(object sender, EventArgs e)
{
if (_viewport.Width != )
{
int firstIndexCache = firstIndex;
_abstractPanel = null;
MeasureOverride(_viewport);
SetFirstRowViewItemIndex(firstIndex);
firstIndex = firstIndexCache;
}
} public int GetFirstVisibleSection()
{
int section;
var maxSection = _abstractPanel.Max(x => x.Section);
if (Orientation == Orientation.Horizontal)
{
section = (int)_offset.Y;
}
else
{
section = (int)_offset.X;
}
if (section > maxSection)
section = maxSection;
return section;
} public int GetFirstVisibleIndex()
{
int section = GetFirstVisibleSection();
var item = _abstractPanel.Where(x => x.Section == section).FirstOrDefault();
if (item != null)
return item._index;
return ;
} private void CleanUpItems(int minDesiredGenerated, int maxDesiredGenerated)
{
for (int i = _children.Count - ; i >= ; i--)
{
GeneratorPosition childGeneratorPos = new GeneratorPosition(i, );
int itemIndex = _generator.IndexFromGeneratorPosition(childGeneratorPos);
if (itemIndex < minDesiredGenerated || itemIndex > maxDesiredGenerated)
{
_generator.Remove(childGeneratorPos, );
RemoveInternalChildRange(i, );
}
}
} private void ComputeExtentAndViewport(Size pixelMeasuredViewportSize, int visibleSections)
{
if (Orientation == Orientation.Horizontal)
{
_viewport.Height = visibleSections;
_viewport.Width = pixelMeasuredViewportSize.Width;
}
else
{
_viewport.Width = visibleSections;
_viewport.Height = pixelMeasuredViewportSize.Height;
} if (Orientation == Orientation.Horizontal)
{
_extent.Height = _abstractPanel.SectionCount + ViewportHeight - ; }
else
{
_extent.Width = _abstractPanel.SectionCount + ViewportWidth - ;
}
_owner.InvalidateScrollInfo();
} private void ResetScrollInfo()
{
_offset.X = ;
_offset.Y = ;
} private int GetNextSectionClosestIndex(int itemIndex)
{
var abstractItem = _abstractPanel[itemIndex];
if (abstractItem.Section < _abstractPanel.SectionCount - )
{
var ret = _abstractPanel.
Where(x => x.Section == abstractItem.Section + ).
OrderBy(x => Math.Abs(x.SectionIndex - abstractItem.SectionIndex)).
First();
return ret._index;
}
else
return itemIndex;
} private int GetLastSectionClosestIndex(int itemIndex)
{
var abstractItem = _abstractPanel[itemIndex];
if (abstractItem.Section > )
{
var ret = _abstractPanel.
Where(x => x.Section == abstractItem.Section - ).
OrderBy(x => Math.Abs(x.SectionIndex - abstractItem.SectionIndex)).
First();
return ret._index;
}
else
return itemIndex;
} private void NavigateDown()
{
var gen = _generator.GetItemContainerGeneratorForPanel(this);
UIElement selected = (UIElement)Keyboard.FocusedElement;
int itemIndex = gen.IndexFromContainer(selected);
int depth = ;
while (itemIndex == -)
{
selected = (UIElement)VisualTreeHelper.GetParent(selected);
itemIndex = gen.IndexFromContainer(selected);
depth++;
}
DependencyObject next = null;
if (Orientation == Orientation.Horizontal)
{
int nextIndex = GetNextSectionClosestIndex(itemIndex);
next = gen.ContainerFromIndex(nextIndex);
while (next == null)
{
SetVerticalOffset(VerticalOffset + );
UpdateLayout();
next = gen.ContainerFromIndex(nextIndex);
}
}
else
{
if (itemIndex == _abstractPanel._itemCount - )
return;
next = gen.ContainerFromIndex(itemIndex + );
while (next == null)
{
SetHorizontalOffset(HorizontalOffset + );
UpdateLayout();
next = gen.ContainerFromIndex(itemIndex + );
}
}
while (depth != )
{
next = VisualTreeHelper.GetChild(next, );
depth--;
}
(next as UIElement).Focus();
} private void NavigateLeft()
{
var gen = _generator.GetItemContainerGeneratorForPanel(this); UIElement selected = (UIElement)Keyboard.FocusedElement;
int itemIndex = gen.IndexFromContainer(selected);
int depth = ;
while (itemIndex == -)
{
selected = (UIElement)VisualTreeHelper.GetParent(selected);
itemIndex = gen.IndexFromContainer(selected);
depth++;
}
DependencyObject next = null;
if (Orientation == Orientation.Vertical)
{
int nextIndex = GetLastSectionClosestIndex(itemIndex);
next = gen.ContainerFromIndex(nextIndex);
while (next == null)
{
SetHorizontalOffset(HorizontalOffset - );
UpdateLayout();
next = gen.ContainerFromIndex(nextIndex);
}
}
else
{
if (itemIndex == )
return;
next = gen.ContainerFromIndex(itemIndex - );
while (next == null)
{
SetVerticalOffset(VerticalOffset - );
UpdateLayout();
next = gen.ContainerFromIndex(itemIndex - );
}
}
while (depth != )
{
next = VisualTreeHelper.GetChild(next, );
depth--;
}
(next as UIElement).Focus();
} private void NavigateRight()
{
var gen = _generator.GetItemContainerGeneratorForPanel(this);
UIElement selected = (UIElement)Keyboard.FocusedElement;
int itemIndex = gen.IndexFromContainer(selected);
int depth = ;
while (itemIndex == -)
{
selected = (UIElement)VisualTreeHelper.GetParent(selected);
itemIndex = gen.IndexFromContainer(selected);
depth++;
}
DependencyObject next = null;
if (Orientation == Orientation.Vertical)
{
int nextIndex = GetNextSectionClosestIndex(itemIndex);
next = gen.ContainerFromIndex(nextIndex);
while (next == null)
{
SetHorizontalOffset(HorizontalOffset + );
UpdateLayout();
next = gen.ContainerFromIndex(nextIndex);
}
}
else
{
if (itemIndex == _abstractPanel._itemCount - )
return;
next = gen.ContainerFromIndex(itemIndex + );
while (next == null)
{
SetVerticalOffset(VerticalOffset + );
UpdateLayout();
next = gen.ContainerFromIndex(itemIndex + );
}
}
while (depth != )
{
next = VisualTreeHelper.GetChild(next, );
depth--;
}
(next as UIElement).Focus();
} private void NavigateUp()
{
var gen = _generator.GetItemContainerGeneratorForPanel(this);
UIElement selected = (UIElement)Keyboard.FocusedElement;
int itemIndex = gen.IndexFromContainer(selected);
int depth = ;
while (itemIndex == -)
{
selected = (UIElement)VisualTreeHelper.GetParent(selected);
itemIndex = gen.IndexFromContainer(selected);
depth++;
}
DependencyObject next = null;
if (Orientation == Orientation.Horizontal)
{
int nextIndex = GetLastSectionClosestIndex(itemIndex);
next = gen.ContainerFromIndex(nextIndex);
while (next == null)
{
SetVerticalOffset(VerticalOffset - );
UpdateLayout();
next = gen.ContainerFromIndex(nextIndex);
}
}
else
{
if (itemIndex == )
return;
next = gen.ContainerFromIndex(itemIndex - );
while (next == null)
{
SetHorizontalOffset(HorizontalOffset - );
UpdateLayout();
next = gen.ContainerFromIndex(itemIndex - );
}
}
while (depth != )
{
next = VisualTreeHelper.GetChild(next, );
depth--;
}
(next as UIElement).Focus();
} #endregion #region Override protected override void OnKeyDown(KeyEventArgs e)
{
switch (e.Key)
{
case Key.Down:
NavigateDown();
e.Handled = true;
break;
case Key.Left:
NavigateLeft();
e.Handled = true;
break;
case Key.Right:
NavigateRight();
e.Handled = true;
break;
case Key.Up:
NavigateUp();
e.Handled = true;
break;
default:
base.OnKeyDown(e);
break;
}
} protected override void OnItemsChanged(object sender, ItemsChangedEventArgs args)
{
base.OnItemsChanged(sender, args);
_abstractPanel = null;
ResetScrollInfo();
} protected override void OnInitialized(EventArgs e)
{
this.SizeChanged += new SizeChangedEventHandler(this.Resizing);
base.OnInitialized(e);
_itemsControl = ItemsControl.GetItemsOwner(this);
_children = InternalChildren;
_generator = ItemContainerGenerator;
} protected override Size MeasureOverride(Size availableSize)
{
if (_itemsControl == null || _itemsControl.Items.Count == )
return availableSize;
if (_abstractPanel == null)
_abstractPanel = new WrapPanelAbstraction(_itemsControl.Items.Count); _pixelMeasuredViewport = availableSize; _realizedChildLayout.Clear(); Size realizedFrameSize = availableSize; int itemCount = _itemsControl.Items.Count;
int firstVisibleIndex = GetFirstVisibleIndex(); GeneratorPosition startPos = _generator.GeneratorPositionFromIndex(firstVisibleIndex); int childIndex = (startPos.Offset == ) ? startPos.Index : startPos.Index + ;
int current = firstVisibleIndex;
int visibleSections = ;
using (_generator.StartAt(startPos, GeneratorDirection.Forward, true))
{
bool stop = false;
bool isHorizontal = Orientation == Orientation.Horizontal;
double currentX = ;
double currentY = ;
double maxItemSize = ;
int currentSection = GetFirstVisibleSection();
while (current < itemCount)
{
bool newlyRealized; // Get or create the child
UIElement child = _generator.GenerateNext(out newlyRealized) as UIElement;
if (newlyRealized)
{
// Figure out if we need to insert the child at the end or somewhere in the middle
if (childIndex >= _children.Count)
{
base.AddInternalChild(child);
}
else
{
base.InsertInternalChild(childIndex, child);
}
_generator.PrepareItemContainer(child);
child.Measure(ChildSlotSize);
}
else
{
// The child has already been created, let's be sure it's in the right spot
Debug.Assert(child == _children[childIndex], "Wrong child was generated");
}
childSize = child.DesiredSize;
Rect childRect = new Rect(new Point(currentX, currentY), childSize);
if (isHorizontal)
{
maxItemSize = Math.Max(maxItemSize, childRect.Height);
if (childRect.Right > realizedFrameSize.Width) //wrap to a new line
{
currentY = currentY + maxItemSize;
currentX = ;
maxItemSize = childRect.Height;
childRect.X = currentX;
childRect.Y = currentY;
currentSection++;
visibleSections++;
}
if (currentY > realizedFrameSize.Height)
stop = true;
currentX = childRect.Right;
}
else
{
maxItemSize = Math.Max(maxItemSize, childRect.Width);
if (childRect.Bottom > realizedFrameSize.Height) //wrap to a new column
{
currentX = currentX + maxItemSize;
currentY = ;
maxItemSize = childRect.Width;
childRect.X = currentX;
childRect.Y = currentY;
currentSection++;
visibleSections++;
}
if (currentX > realizedFrameSize.Width)
stop = true;
currentY = childRect.Bottom;
}
_realizedChildLayout.Add(child, childRect);
_abstractPanel.SetItemSection(current, currentSection); if (stop)
break;
current++;
childIndex++;
}
}
CleanUpItems(firstVisibleIndex, current - ); ComputeExtentAndViewport(availableSize, visibleSections); return availableSize;
}
protected override Size ArrangeOverride(Size finalSize)
{
if (_children != null)
{
foreach (UIElement child in _children)
{
var layoutInfo = _realizedChildLayout[child];
child.Arrange(layoutInfo);
}
}
return finalSize;
} #endregion #region IScrollInfo Members private bool _canHScroll = false;
public bool CanHorizontallyScroll
{
get { return _canHScroll; }
set { _canHScroll = value; }
} private bool _canVScroll = false;
public bool CanVerticallyScroll
{
get { return _canVScroll; }
set { _canVScroll = value; }
} public double ExtentHeight
{
get { return _extent.Height; }
} public double ExtentWidth
{
get { return _extent.Width; }
} public double HorizontalOffset
{
get { return _offset.X; }
} public double VerticalOffset
{
get { return _offset.Y; }
} public void LineDown()
{
if (Orientation == Orientation.Vertical)
SetVerticalOffset(VerticalOffset + );
else
SetVerticalOffset(VerticalOffset + );
} public void LineLeft()
{
if (Orientation == Orientation.Horizontal)
SetHorizontalOffset(HorizontalOffset - );
else
SetHorizontalOffset(HorizontalOffset - );
} public void LineRight()
{
if (Orientation == Orientation.Horizontal)
SetHorizontalOffset(HorizontalOffset + );
else
SetHorizontalOffset(HorizontalOffset + );
} public void LineUp()
{
if (Orientation == Orientation.Vertical)
SetVerticalOffset(VerticalOffset - );
else
SetVerticalOffset(VerticalOffset - );
} public Rect MakeVisible(Visual visual, Rect rectangle)
{
var gen = (ItemContainerGenerator)_generator.GetItemContainerGeneratorForPanel(this);
var element = (UIElement)visual;
int itemIndex = gen.IndexFromContainer(element);
while (itemIndex == -)
{
element = (UIElement)VisualTreeHelper.GetParent(element);
itemIndex = gen.IndexFromContainer(element);
}
int section = _abstractPanel[itemIndex].Section;
Rect elementRect = _realizedChildLayout[element];
if (Orientation == Orientation.Horizontal)
{
double viewportHeight = _pixelMeasuredViewport.Height;
if (elementRect.Bottom > viewportHeight)
_offset.Y += ;
else if (elementRect.Top < )
_offset.Y -= ;
}
else
{
double viewportWidth = _pixelMeasuredViewport.Width;
if (elementRect.Right > viewportWidth)
_offset.X += ;
else if (elementRect.Left < )
_offset.X -= ;
}
InvalidateMeasure();
return elementRect;
} public void MouseWheelDown()
{
PageDown();
} public void MouseWheelLeft()
{
PageLeft();
} public void MouseWheelRight()
{
PageRight();
} public void MouseWheelUp()
{
PageUp();
} public void PageDown()
{
SetVerticalOffset(VerticalOffset + _viewport.Height * 0.8);
} public void PageLeft()
{
SetHorizontalOffset(HorizontalOffset - _viewport.Width * 0.8);
} public void PageRight()
{
SetHorizontalOffset(HorizontalOffset + _viewport.Width * 0.8);
} public void PageUp()
{
SetVerticalOffset(VerticalOffset - _viewport.Height * 0.8);
} private ScrollViewer _owner;
public ScrollViewer ScrollOwner
{
get { return _owner; }
set { _owner = value; }
} public void SetHorizontalOffset(double offset)
{
if (offset < || _viewport.Width >= _extent.Width)
{
offset = ;
}
else
{
if (offset + _viewport.Width >= _extent.Width)
{
offset = _extent.Width - _viewport.Width;
}
} _offset.X = offset; if (_owner != null)
_owner.InvalidateScrollInfo(); InvalidateMeasure();
firstIndex = GetFirstVisibleIndex();
} public void SetVerticalOffset(double offset)
{
if (offset < || _viewport.Height >= _extent.Height)
{
offset = ;
}
else
{
if (offset + _viewport.Height >= _extent.Height)
{
offset = _extent.Height - _viewport.Height;
}
} _offset.Y = offset; if (_owner != null)
_owner.InvalidateScrollInfo(); //_trans.Y = -offset; InvalidateMeasure();
firstIndex = GetFirstVisibleIndex();
} public double ViewportHeight
{
get { return _viewport.Height; }
} public double ViewportWidth
{
get { return _viewport.Width; }
} #endregion #region helper data structures class ItemAbstraction
{
public ItemAbstraction(WrapPanelAbstraction panel, int index)
{
_panel = panel;
_index = index;
} WrapPanelAbstraction _panel; public readonly int _index; int _sectionIndex = -;
public int SectionIndex
{
get
{
if (_sectionIndex == -)
{
return _index % _panel._averageItemsPerSection - ;
}
return _sectionIndex;
}
set
{
if (_sectionIndex == -)
_sectionIndex = value;
}
} int _section = -;
public int Section
{
get
{
if (_section == -)
{
return _index / _panel._averageItemsPerSection;
}
return _section;
}
set
{
if (_section == -)
_section = value;
}
}
} class WrapPanelAbstraction : IEnumerable<ItemAbstraction>
{
public WrapPanelAbstraction(int itemCount)
{
List<ItemAbstraction> items = new List<ItemAbstraction>(itemCount);
for (int i = ; i < itemCount; i++)
{
ItemAbstraction item = new ItemAbstraction(this, i);
items.Add(item);
} Items = new ReadOnlyCollection<ItemAbstraction>(items);
_averageItemsPerSection = itemCount;
_itemCount = itemCount;
} public readonly int _itemCount;
public int _averageItemsPerSection;
private int _currentSetSection = -;
private int _currentSetItemIndex = -;
private int _itemsInCurrentSecction = ;
private object _syncRoot = new object(); public int SectionCount
{
get
{
int ret = _currentSetSection + ;
if (_currentSetItemIndex + < Items.Count)
{
int itemsLeft = Items.Count - _currentSetItemIndex;
ret += itemsLeft / _averageItemsPerSection + ;
}
return ret;
}
} private ReadOnlyCollection<ItemAbstraction> Items { get; set; } public void SetItemSection(int index, int section)
{
lock (_syncRoot)
{
if (section <= _currentSetSection + && index == _currentSetItemIndex + )
{
_currentSetItemIndex++;
Items[index].Section = section;
if (section == _currentSetSection + )
{
_currentSetSection = section;
if (section > )
{
_averageItemsPerSection = (index) / (section);
}
_itemsInCurrentSecction = ;
}
else
_itemsInCurrentSecction++;
Items[index].SectionIndex = _itemsInCurrentSecction - ;
}
}
} public ItemAbstraction this[int index]
{
get { return Items[index]; }
} #region IEnumerable<ItemAbstraction> Members public IEnumerator<ItemAbstraction> GetEnumerator()
{
return Items.GetEnumerator();
} #endregion #region IEnumerable Members System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return GetEnumerator();
} #endregion
} #endregion
}
最新文章
- VS2013常用快捷键
- Mecanim动画系统 制作流程
- xampp改到phpmyadmin的root密碼無法登錄
- hdu4453 Looploop 2012年杭州现场赛 Splay
- Apache错误：(20014)Internal error: Error retrieving pid file logs/httpd.pid
- 小技巧：selenium java中如何使用chrome默认的profile
- JavaScript网页全屏API
- jquery取出checkbox多选的值(带全选功能)
- golang基础学习及web框架
- 北洋UAM-05LX（网口系列适用）ROS节点
- WPF应用Access数据库
- Hibernate 再接触 基础配置 续
- 【java】开发中常用字符串方法
- JavaScript 字符串(String)对象
- Oracle 大小写转换函数
- slub分配器
- 检查路径是否存在与创建指定路径（mfc)
- python redis 方法大全
- 创建数据收集器集(DSC)
- ios网络模拟