有没有办法自动占用WrapPanel中的空白区域？
WrapPanel的子项按顺序填充，如附加的屏幕截图。
因此，根据每个孩子的长度，面板会留出很长的空白。
我怎样才能利用空白区重新安排孩子们？
到目前为止，似乎只有少数人使用WrapPanel而且没有足够的例子。
这有什么自动方式吗？ 或者我只需要制作自己的算法？
WrapPanel在显示内容方面起着非常重要的作用，但显示空间有限。
谢谢 ！
这是一个WrapPanel，可以选择使用FFDH算法重新排列元素，也可以选择拉伸它们以删除空白区域（ 示例 ）。
public class StretchyWrapPanel : Panel { public static readonly DependencyProperty ItemWidthProperty = DependencyProperty.Register(nameof(ItemWidth), typeof(double), typeof(StretchyWrapPanel), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsMeasure, (o, e) => { ((StretchyWrapPanel)o)._itemWidth = (double)e.NewValue; })); private double _itemWidth = double.NaN; [TypeConverter(typeof(LengthConverter))] public double ItemWidth { get => _itemWidth; set => SetValue(ItemWidthProperty, value); } public static readonly DependencyProperty ItemHeightProperty = DependencyProperty.Register(nameof(ItemHeight), typeof(double), typeof(StretchyWrapPanel), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsMeasure, (o, e) => { ((StretchyWrapPanel)o)._itemHeight = (double)e.NewValue; })); private double _itemHeight = double.NaN; [TypeConverter(typeof(LengthConverter))] public double ItemHeight { get => _itemHeight; set => SetValue(ItemHeightProperty, value); } public static readonly DependencyProperty OrientationProperty = DependencyProperty.Register(nameof(Orientation), typeof(Orientation), typeof(StretchyWrapPanel), new FrameworkPropertyMetadata(Orientation.Horizontal, FrameworkPropertyMetadataOptions.AffectsArrange, (o, e) => { ((StretchyWrapPanel)o)._orientation = (Orientation)e.NewValue; })); private Orientation _orientation = Orientation.Horizontal; public Orientation Orientation { get => _orientation; set => SetValue(OrientationProperty, value); } public static readonly DependencyProperty StretchToFillProperty = DependencyProperty.Register(nameof(StretchToFill), typeof(bool), typeof(StretchyWrapPanel), new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.AffectsArrange, (o, e) => { ((StretchyWrapPanel)o)._stretchToFill = (bool)e.NewValue; })); private bool _stretchToFill = true; public bool StretchToFill { get => _stretchToFill; set => SetValue(StretchToFillProperty, value); } public static readonly DependencyProperty StretchProportionallyProperty = DependencyProperty.Register(nameof(StretchProportionally), typeof(bool), typeof(StretchyWrapPanel), new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.AffectsArrange, (o, e) => { ((StretchyWrapPanel)o)._stretchProportionally = (bool)e.NewValue; })); private bool _stretchProportionally = true; public bool StretchProportionally { get => _stretchProportionally; set => SetValue(StretchProportionallyProperty, value); } public static readonly DependencyProperty RearrangeForBestFitProperty = DependencyProperty.Register(nameof(RearrangeForBestFit), typeof(bool), typeof(StretchyWrapPanel), new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.AffectsMeasure, (o, e) => { ((StretchyWrapPanel)o)._rearrangeForBestFit = (bool)e.NewValue; })); private bool _rearrangeForBestFit; public bool RearrangeForBestFit { get => _rearrangeForBestFit; set => SetValue(RearrangeForBestFitProperty, value); } private struct UVSize { internal UVSize(Orientation orientation, Size size) { U = V = 0d; _isHorizontal = orientation == Orientation.Horizontal; Width = size.Width; Height = size.Height; } internal UVSize(Orientation orientation, double width, double height) { U = V = 0d; _isHorizontal = orientation == Orientation.Horizontal; Width = width; Height = height; } internal UVSize(Orientation orientation) { U = V = 0d; _isHorizontal = orientation == Orientation.Horizontal; } internal double U; internal double V; private bool _isHorizontal; internal double Width { get => _isHorizontal ? U : V; set { if (_isHorizontal) { U = value; } else { V = value; } } } internal double Height { get => _isHorizontal ? V : U; set { if (_isHorizontal) { V = value; } else { U = value; } } } } protected override Size MeasureOverride(Size constraint) { return RearrangeForBestFit ? MeasureBestFit(constraint) : MeasureKeepInOrder(constraint); } private Size MeasureKeepInOrder(Size constraint) { var orientation = Orientation; var uLimit = new UVSize(orientation, constraint.Width, constraint.Height).U; var curLineSize = new UVSize(orientation); var panelSize = new UVSize(orientation); var itemWidth = ItemWidth; var itemHeight = ItemHeight; var itemWidthSet = !double.IsNaN(itemWidth); var itemHeightSet = !double.IsNaN(itemHeight); var childConstraint = new Size( itemWidthSet ? itemWidth : constraint.Width, itemHeightSet ? itemHeight : constraint.Height); var children = InternalChildren; for (int i = 0, count = children.Count; i < count; i++) { var child = children[i]; if (child == null) continue; // Flow passes its own constrint to children child.Measure(childConstraint); // This is the size of the child in UV space var sz = new UVSize(orientation, itemWidthSet ? itemWidth : child.DesiredSize.Width, itemHeightSet ? itemHeight : child.DesiredSize.Height); if (curLineSize.U + sz.U > uLimit) { // Need to switch to another line panelSize.U = Math.Max(curLineSize.U, panelSize.U); panelSize.V += curLineSize.V; curLineSize = sz; if (sz.U > uLimit) { // The element is wider then the constrint - give it a separate line panelSize.U = Math.Max(sz.U, panelSize.U); panelSize.V += sz.V; curLineSize = new UVSize(orientation); } } else { // Continue to accumulate a line curLineSize.U += sz.U; curLineSize.V = Math.Max(sz.V, curLineSize.V); } } // The last line size, if any should be added panelSize.U = Math.Max(curLineSize.U, panelSize.U); panelSize.V += curLineSize.V; // Go from UV space to W/H space return new Size(panelSize.Width, panelSize.Height); } private Size MeasureBestFit(Size constraint) { var orientation = Orientation; var uLimit = new UVSize(orientation, constraint.Width, constraint.Height).U; var itemWidth = ItemWidth; var itemHeight = ItemHeight; var itemWidthSet = !double.IsNaN(itemWidth); var itemHeightSet = !double.IsNaN(itemHeight); var childConstraint = new Size( itemWidthSet ? itemWidth : constraint.Width, itemHeightSet ? itemHeight : constraint.Height); var children = InternalChildren; // First-Fit Decreasing Height (FFDH) algorithm var lines = new List(); for (int i = 0, count = children.Count; i < count; i++) { var child = children[i]; if (child == null) continue; // Flow passes its own constrint to children child.Measure(childConstraint); // This is the size of the child in UV space var childSize = new UVSize(orientation, itemWidthSet ? itemWidth : child.DesiredSize.Width, itemHeightSet ? itemHeight : child.DesiredSize.Height); for (var j = 0; j < lines.Count; j++) { var line = lines[j]; if (line.U + childSize.U <= uLimit) { lines[j] = new UVSize(orientation) { U = childSize.U, V = Math.Max(childSize.V, line.V) }; goto Next; } } lines.Add(childSize); Next: { } } var panelSize = new UVSize(orientation); for (var i = 0; i < lines.Count; i++) { var line = lines[i]; panelSize.U = Math.Max(line.U, panelSize.U); panelSize.V += line.V; } // Go from UV space to W/H space return new Size(panelSize.Width, panelSize.Height); } protected override Size ArrangeOverride(Size finalSize) { return RearrangeForBestFit ? ArrangeBestFit(finalSize) : ArrangeKeepInOrder(finalSize); } private static UVSize GetChildSize(Orientation orientation, UIElement child, UVSize fixedChildSize) { var childSize = new UVSize(orientation, child.DesiredSize); if (!double.IsNaN(fixedChildSize.U)) childSize.U = fixedChildSize.U; if (!double.IsNaN(fixedChildSize.V)) childSize.V = fixedChildSize.V; return childSize; } private Size ArrangeKeepInOrder(Size finalSize) { var orientation = Orientation; var fixedChildSize = new UVSize(orientation, ItemWidth, ItemHeight); var children = InternalChildren; var firstInLine = 0; var uLimit = new UVSize(orientation, finalSize).U; var currentLineSize = new UVSize(orientation); var accumulatedV = 0d; for (int i = 0, count = children.Count; i < count; i++) { var child = children[i]; if (child == null) continue; var childSize = GetChildSize(orientation, child, fixedChildSize); if (currentLineSize.U + childSize.U > uLimit) { // Need to switch to another line if (!double.IsNaN(fixedChildSize.U)) { ArrangeLineFixedSize(orientation, children, accumulatedV, currentLineSize.V, firstInLine, i, fixedChildSize.U); } else if (!StretchToFill) { ArrangeLineDefault(orientation, children, accumulatedV, currentLineSize.V, firstInLine, i); } else { ArrangeLineStretch(orientation, children, accumulatedV, currentLineSize.V, firstInLine, i, uLimit, StretchProportionally); } accumulatedV += currentLineSize.V; currentLineSize = childSize; firstInLine = i; } else { // Continue to accumulate a line currentLineSize.U += childSize.U; currentLineSize.V = Math.Max(childSize.V, currentLineSize.V); } } // Arrange the last line, if any if (!double.IsNaN(fixedChildSize.U)) { ArrangeLineFixedSize(orientation, children, accumulatedV, currentLineSize.V, firstInLine, children.Count, fixedChildSize.U); } else if (!StretchToFill) { ArrangeLineDefault(orientation, children, accumulatedV, currentLineSize.V, firstInLine, children.Count); } else { ArrangeLineStretch(orientation, children, accumulatedV, currentLineSize.V, firstInLine, children.Count, uLimit, StretchProportionally); } return finalSize; } private static void ArrangeLineDefault(Orientation orientation, UIElementCollection children, double v, double lineV, int start, int end) { var position = new UVSize(orientation){ U = 0d, V = v }; for (var i = start; i < end; i++) { var child = children[i]; if (child != null) { var childSize = new UVSize(orientation, child.DesiredSize) { V = lineV }; child.Arrange(new Rect(position.Width, position.Height, childSize.Width, childSize.Height)); position.U += childSize.U; } } } private static void ArrangeLineStretch(Orientation orientation, UIElementCollection children, double v, double lineV, int start, int end, double limitU, bool stretchProportionally) { var totalU = 0d; for (var i = start; i < end; i++) { totalU += new UVSize(orientation, children[i].DesiredSize).U; } var position = new UVSize(orientation) { U = 0d, V = v }; var uExtra = stretchProportionally ? limitU / totalU : (limitU - totalU) / (end - start); for (var i = start; i < end; i++) { var child = children[i]; if (child != null) { var childSize = new UVSize(orientation, child.DesiredSize) { V = lineV }; childSize.U = stretchProportionally ? childSize.U * uExtra : Math.Max(childSize.U + uExtra, 1d); child.Arrange(new Rect(position.Width, position.Height, childSize.Width, childSize.Height)); position.U += childSize.U; } } } private static void ArrangeLineFixedSize(Orientation orientation, UIElementCollection children, double v, double lineV, int start, int end, double itemU) { var position = new UVSize(orientation) { U = 0d, V = v }; var childSize = new UVSize(orientation){ U = itemU, V = lineV }; for (var i = start; i < end; i++) { var child = children[i]; if (child != null) { child.Arrange(new Rect(position.Width, position.Height, childSize.Width, childSize.Height)); position.U += childSize.U; } } } private class ArrangeBestFitLine { public UVSize Size; public readonly List ItemIndices = new List (); public void ArrangeDefault(Orientation orientation, UIElementCollection children, double v) { var position = new UVSize(orientation){ U = 0d, V = v }; for (var i = 0; i < ItemIndices.Count; i++) { var child = children[ItemIndices[i]]; if (child != null) { var childSize = new UVSize(orientation, child.DesiredSize) { V = Size.V }; child.Arrange(new Rect(position.Width, position.Height, childSize.Width, childSize.Height)); position.U += childSize.U; } } } public void ArrangeStretch(Orientation orientation, UIElementCollection children, double v, double limitU, bool stretchProportionally) { var totalU = 0d; for (var i = 0; i < ItemIndices.Count; i++) { totalU += new UVSize(orientation, children[ItemIndices[i]].DesiredSize).U; } var position = new UVSize(orientation) { U = 0d, V = v }; var uExtra = stretchProportionally ? limitU / totalU : (limitU - totalU) / ItemIndices.Count; for (var i = 0; i < ItemIndices.Count; i++) { var child = children[ItemIndices[i]]; if (child != null) { var childSize = new UVSize(orientation, child.DesiredSize) { V = Size.V }; childSize.U = stretchProportionally ? childSize.U * uExtra : Math.Max(childSize.U + uExtra, 1d); child.Arrange(new Rect(position.Width, position.Height, childSize.Width, childSize.Height)); position.U += childSize.U; } } } public void ArrangeFixedSize(Orientation orientation, UIElementCollection children, double v, double itemU) { var position = new UVSize(orientation) { U = 0d, V = v }; var childSize = new UVSize(orientation){ U = itemU, V = Size.V }; for (var i = 0; i < ItemIndices.Count; i++) { var child = children[ItemIndices[i]]; if (child != null) { child.Arrange(new Rect(position.Width, position.Height, childSize.Width, childSize.Height)); position.U += childSize.U; } } } } private Size ArrangeBestFit(Size finalSize) { var orientation = Orientation; var fixedChildSize = new UVSize(orientation, ItemWidth, ItemHeight); var uLimit = new UVSize(orientation, finalSize).U; // First-Fit Decreasing Height (FFDH) algorithm var lines = new List(); var children = InternalChildren; for (int i = 0, count = children.Count; i < count; i++) { var child = children[i]; if (child == null) continue; var childSize = GetChildSize(orientation, child, fixedChildSize); for (var j = 0; j < lines.Count; j++) { var line = lines[j]; if (line.Size.U + childSize.U <= uLimit) { line.Size.U += childSize.U; line.Size.V = Math.Max(childSize.V, line.Size.V); line.ItemIndices.Add(i); goto Next; } } lines.Add(new ArrangeBestFitLine { Size = childSize, ItemIndices = { i } }); Next: { } } var accumulatedV = 0d; for (var i = 0; i < lines.Count; i++) { var line = lines[i]; if (!double.IsNaN(fixedChildSize.U)) { line.ArrangeFixedSize(orientation, children, accumulatedV, fixedChildSize.U); } else if (!StretchToFill) { line.ArrangeDefault(orientation, children, accumulatedV); } else { line.ArrangeStretch(orientation, children, accumulatedV, uLimit, StretchProportionally); } accumulatedV += line.Size.V; } return finalSize; } } 你在WrapPanel中的所有元素都是相同的高度吗？ 在任何一种情况下，为什么不从像https://marketplace.visualstudio.com/items?itemName=DevExpress.WPFTreeMapControl这样的TreeMap控件开始并自定义它？
编辑1 – 根据评论
它实现起来应该不会太难 – 我很确定通过从面板inheritance并在其MeasureOverride和ArrangeOverride方法中挂钩重新排列的代码，可以实现所需的最小function。 看看这里（实现类似的控制），如果你选择这样做可能是一个好的开始： https ： //codeblitz.wordpress.com/2009/03/20/wpf-auto-arrange-animated-panel/
这个简单的小组应该做的工作：
public class MySpecialWrapPanel : Panel { protected override Size MeasureOverride(Size availableSize) { foreach (UIElement child in InternalChildren) { child.Measure(availableSize); } return new Size(); } protected override Size ArrangeOverride(Size finalSize) { var x = 0d; var y = 0d; var height = 0d; var children = InternalChildren.Cast().ToList(); while (children.Count > 0) { var child = children.First(); if (x > 0d && x + child.DesiredSize.Width > finalSize.Width) { // try to find child that fits var fit = children.FirstOrDefault( c => x + c.DesiredSize.Width <= finalSize.Width); child = fit ?? child; if (x + child.DesiredSize.Width > finalSize.Width) { x = 0d; y = height; } } children.Remove(child); child.Arrange( new Rect(x, y, child.DesiredSize.Width, child.DesiredSize.Height)); x += child.DesiredSize.Width; height = Math.Max(height, y + child.DesiredSize.Height); } return finalSize; } }
你需要一个自定义算法。 我相信这里提到的StretchyWrapPanel是一个好的开始。 在测量子项目之后，您可以使用自定义逻辑（例如bin packing ）对它们进行排序。