WPF - كيف يمكنني مركز كل العناصر في WrapPanel?

Question

أنا باستخدام WrapPanel كما ItemsPanel من ItemsControl.الآن العناصر في السيطرة التفاف مثل هذا:

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|890      |

أود منهم أن التفاف مثل هذا:

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|   890   |

من الناحية النظرية, تخطيط عملية محاذاة كل سطر من البنود بحيث انها تركزت في WrapPanel's حدود.

يمكن للشخص أن يفسر كيف أن هذا أمر ممكن من فضلك ؟

Answer 1

وبنيت في WrapPanel لن تسمح لك محاذاة مضمونه - فقط في حد ذاته. هنا هو الاسلوب الذي يسمح لك تعيين HorizontalContentAlignment:

using System;
using System.Windows;
using System.Windows.Controls;

public class AlignableWrapPanel : Panel
{
    public HorizontalAlignment HorizontalContentAlignment
    {
        get { return (HorizontalAlignment)GetValue(HorizontalContentAlignmentProperty); }
        set { SetValue(HorizontalContentAlignmentProperty, value); }
    }

    public static readonly DependencyProperty HorizontalContentAlignmentProperty =
        DependencyProperty.Register("HorizontalContentAlignment", typeof(HorizontalAlignment), typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(HorizontalAlignment.Left, FrameworkPropertyMetadataOptions.AffectsArrange));

    protected override Size MeasureOverride(Size constraint)
    {
        Size curLineSize = new Size();
        Size panelSize = new Size();

        UIElementCollection children = base.InternalChildren;

        for (int i = 0; i < children.Count; i++)
        {
            UIElement child = children[i] as UIElement;

            // Flow passes its own constraint to children
            child.Measure(constraint);
            Size sz = child.DesiredSize;

            if (curLineSize.Width + sz.Width > constraint.Width) //need to switch to another line
            {
                panelSize.Width = Math.Max(curLineSize.Width, panelSize.Width);
                panelSize.Height += curLineSize.Height;
                curLineSize = sz;

                if (sz.Width > constraint.Width) // if the element is wider then the constraint - give it a separate line                    
                {
                    panelSize.Width = Math.Max(sz.Width, panelSize.Width);
                    panelSize.Height += sz.Height;
                    curLineSize = new Size();
                }
            }
            else //continue to accumulate a line
            {
                curLineSize.Width += sz.Width;
                curLineSize.Height = Math.Max(sz.Height, curLineSize.Height);
            }
        }

        // the last line size, if any need to be added
        panelSize.Width = Math.Max(curLineSize.Width, panelSize.Width);
        panelSize.Height += curLineSize.Height;

        return panelSize;
    }

    protected override Size ArrangeOverride(Size arrangeBounds)
    {
        int firstInLine = 0;
        Size curLineSize = new Size();
        double accumulatedHeight = 0;
        UIElementCollection children = this.InternalChildren;

        for (int i = 0; i < children.Count; i++)
        {
            Size sz = children[i].DesiredSize;

            if (curLineSize.Width + sz.Width > arrangeBounds.Width) //need to switch to another line
            {
                ArrangeLine(accumulatedHeight, curLineSize, arrangeBounds.Width, firstInLine, i);

                accumulatedHeight += curLineSize.Height;
                curLineSize = sz;

                if (sz.Width > arrangeBounds.Width) //the element is wider then the constraint - give it a separate line                    
                {
                    ArrangeLine(accumulatedHeight, sz, arrangeBounds.Width, i, ++i);
                    accumulatedHeight += sz.Height;
                    curLineSize = new Size();
                }
                firstInLine = i;
            }
            else //continue to accumulate a line
            {
                curLineSize.Width += sz.Width;
                curLineSize.Height = Math.Max(sz.Height, curLineSize.Height);
            }
        }

        if (firstInLine < children.Count)
            ArrangeLine(accumulatedHeight, curLineSize, arrangeBounds.Width, firstInLine, children.Count);

        return arrangeBounds;
    }

    private void ArrangeLine(double y, Size lineSize, double boundsWidth, int start, int end)
    {
        double x = 0;
        if (this.HorizontalContentAlignment == HorizontalAlignment.Center)
        {
            x = (boundsWidth - lineSize.Width) / 2;
        }
        else if (this.HorizontalContentAlignment == HorizontalAlignment.Right)
        {
            x = (boundsWidth - lineSize.Width);
        }

        UIElementCollection children = InternalChildren;
        for (int i = start; i < end; i++)
        {
            UIElement child = children[i];
            child.Arrange(new Rect(x, y, child.DesiredSize.Width, lineSize.Height));
            x += child.DesiredSize.Width;
        }
    }
}

Answer 2

ومما يؤسف له أن الأسهم سوف WrapPanel لا تفعل ما كنت طالبا، لأن نيته هي لملء كل المساحة المتاحة أفقيا (أو عموديا) قبل التفاف. وربما لديك لتصميم WrapPanel الخاص للتعامل مع هذه القضية. هل يمكن أن تبدأ مع هذه العينة يوضح كيفية إنشاء الخاصة بك WrapPanel .

Answer 3

والنسخة مع VerticalContentAlignment (لوحات العمودي):

public class AlignableWrapPanel : Panel {
    public AlignableWrapPanel() {
        _orientation = Orientation.Horizontal;
    }

    private static bool IsWidthHeightValid(object value) {
        var v = (double)value;
        return (double.IsNaN(v)) || (v >= 0.0d && !double.IsPositiveInfinity(v));
    }

    public static readonly DependencyProperty ItemWidthProperty = DependencyProperty.Register("ItemWidth", typeof(double),
            typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsMeasure),
            IsWidthHeightValid);

    [TypeConverter(typeof(LengthConverter))]
    public double ItemWidth {
        get { return (double)GetValue(ItemWidthProperty); }
        set { SetValue(ItemWidthProperty, value); }
    }

    public static readonly DependencyProperty ItemHeightProperty = DependencyProperty.Register("ItemHeight", typeof(double),
            typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(double.NaN, FrameworkPropertyMetadataOptions.AffectsMeasure),
            IsWidthHeightValid);

    [TypeConverter(typeof(LengthConverter))]
    public double ItemHeight {
        get { return (double)GetValue(ItemHeightProperty); }
        set { SetValue(ItemHeightProperty, value); }
    }

    public static readonly DependencyProperty OrientationProperty = StackPanel.OrientationProperty.AddOwner(typeof(AlignableWrapPanel),
            new FrameworkPropertyMetadata(Orientation.Horizontal, FrameworkPropertyMetadataOptions.AffectsMeasure, OnOrientationChanged));

    public Orientation Orientation {
        get { return _orientation; }
        set { SetValue(OrientationProperty, value); }
    }

    private static void OnOrientationChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
        var p = (AlignableWrapPanel)d;
        p._orientation = (Orientation)e.NewValue;
    }

    private Orientation _orientation;

    private struct UvSize {
        internal UvSize(Orientation orientation, double width, double height) {
            U = V = 0d;
            _orientation = orientation;
            Width = width;
            Height = height;
        }

        internal UvSize(Orientation orientation) {
            U = V = 0d;
            _orientation = orientation;
        }

        internal double U;
        internal double V;
        private readonly Orientation _orientation;

        internal double Width {
            get { return (_orientation == Orientation.Horizontal ? U : V); }
            private set { if (_orientation == Orientation.Horizontal) U = value; else V = value; }
        }

        internal double Height {
            get { return (_orientation == Orientation.Horizontal ? V : U); }
            private set { if (_orientation == Orientation.Horizontal) V = value; else U = value; }
        }
    }

    protected override Size MeasureOverride(Size constraint) {
        var curLineSize = new UvSize(Orientation);
        var panelSize = new UvSize(Orientation);
        var uvConstraint = new UvSize(Orientation, constraint.Width, constraint.Height);
        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 > uvConstraint.U) {
                //need to switch to another line 
                panelSize.U = Math.Max(curLineSize.U, panelSize.U);
                panelSize.V += curLineSize.V;
                curLineSize = sz;

                if (!(sz.U > uvConstraint.U)) continue;
                //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);
    }

    protected override Size ArrangeOverride(Size finalSize) {
        var firstInLine = 0;
        var itemWidth = ItemWidth;
        var itemHeight = ItemHeight;
        double accumulatedV = 0;
        var itemU = (Orientation == Orientation.Horizontal ? itemWidth : itemHeight);
        var curLineSize = new UvSize(Orientation);
        var uvFinalSize = new UvSize(Orientation, finalSize.Width, finalSize.Height);
        var itemWidthSet = !double.IsNaN(itemWidth);
        var itemHeightSet = !double.IsNaN(itemHeight);
        var useItemU = (Orientation == Orientation.Horizontal ? itemWidthSet : itemHeightSet);

        var children = InternalChildren;

        for (int i = 0, count = children.Count; i < count; i++) {
            var child = children[i];
            if (child == null) continue;

            var sz = new UvSize(
                    Orientation,
                    (itemWidthSet ? itemWidth : child.DesiredSize.Width),
                    (itemHeightSet ? itemHeight : child.DesiredSize.Height));

            if (curLineSize.U + sz.U > uvFinalSize.U) {
                //need to switch to another line 
                ArrangeLine(finalSize, accumulatedV, curLineSize, firstInLine, i, useItemU, itemU);

                accumulatedV += curLineSize.V;
                curLineSize = sz;

                if (sz.U > uvFinalSize.U) {
                    //the element is wider then the constraint - give it a separate line 
                    //switch to next line which only contain one element 
                    ArrangeLine(finalSize, accumulatedV, sz, i, ++i, useItemU, itemU);

                    accumulatedV += sz.V;
                    curLineSize = new UvSize(Orientation);
                }

                firstInLine = i;
            } else {
                //continue to accumulate a line
                curLineSize.U += sz.U;
                curLineSize.V = Math.Max(sz.V, curLineSize.V);
            }
        }

        //arrange the last line, if any
        if (firstInLine < children.Count) {
            ArrangeLine(finalSize, accumulatedV, curLineSize, firstInLine, children.Count, useItemU, itemU);
        }

        return finalSize;
    }

    private void ArrangeLine(Size finalSize, double v, UvSize line, int start, int end, bool useItemU, double itemU) {
        double u;
        var isHorizontal = Orientation == Orientation.Horizontal;

        if (_orientation == Orientation.Vertical) {
            switch (VerticalContentAlignment) {
                case VerticalAlignment.Center:
                    u = (finalSize.Height - line.U) / 2;
                    break;
                case VerticalAlignment.Bottom:
                    u = finalSize.Height - line.U;
                    break;
                default:
                    u = 0;
                    break;
            }
        } else {
            switch (HorizontalContentAlignment) {
                case HorizontalAlignment.Center:
                    u = (finalSize.Width - line.U) / 2;
                    break;
                case HorizontalAlignment.Right:
                    u = finalSize.Width - line.U;
                    break;
                default:
                    u = 0;
                    break;
            }
        }

        var children = InternalChildren;
        for (var i = start; i < end; i++) {
            var child = children[i];
            if (child == null) continue;
            var childSize = new UvSize(Orientation, child.DesiredSize.Width, child.DesiredSize.Height);
            var layoutSlotU = (useItemU ? itemU : childSize.U);
            child.Arrange(new Rect(
                    isHorizontal ? u : v,
                    isHorizontal ? v : u,
                    isHorizontal ? layoutSlotU : line.V,
                    isHorizontal ? line.V : layoutSlotU));
            u += layoutSlotU;
        }
    }

    public static readonly DependencyProperty HorizontalContentAlignmentProperty = DependencyProperty.Register(nameof(HorizontalContentAlignment), typeof(HorizontalAlignment),
            typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(HorizontalAlignment.Left, FrameworkPropertyMetadataOptions.AffectsArrange));

    public HorizontalAlignment HorizontalContentAlignment {
        get { return (HorizontalAlignment)GetValue(HorizontalContentAlignmentProperty); }
        set { SetValue(HorizontalContentAlignmentProperty, value); }
    }

    public static readonly DependencyProperty VerticalContentAlignmentProperty = DependencyProperty.Register(nameof(VerticalContentAlignment), typeof(VerticalAlignment),
            typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(VerticalAlignment.Top, FrameworkPropertyMetadataOptions.AffectsArrange));

    public VerticalAlignment VerticalContentAlignment {
        get { return (VerticalAlignment)GetValue(VerticalContentAlignmentProperty); }
        set { SetValue(VerticalContentAlignmentProperty, value); }
    }
}

Answer 4

والجواب البسيط هو أنه لا يمكنك توسيط محاذاة محتويات WrapPanel. يمكنك توسيط محاذاة الفريق نفسه، ولكن ستظل اليسار محاذاة السطر الأخير في لوحة.

والاقتراحات Alterate:

واستخدام الشبكة مع الصفوف والأعمدة. إذا كنت لا إضافة عناصر إلى جمع حيوي، وهذا يمكن أن تعمل بشكل جيد.

إنشاء نسختك الخاصة من WrapPanel أن يعمل بالطريقة كنت في حاجة إليها ل. هذه الوثيقة MSDN يصف كيفية عمل لوحات ويتضمن القسم الخاص خلق لوحات مخصصة. كما أن لديها وصلة لوحة مخصصة عينة.

Answer 5

وهنا هو إصدار سيلفرلايت

وشكر خاص ل@DTig،

using System.Windows.Controls;
using System.Windows;
using Telerik.Windows;
using System;
using System.Linq;

public class AlignableWrapPanel : Panel
{
    public HorizontalAlignment HorizontalContentAlignment
    {
        get { return (HorizontalAlignment)GetValue(HorizontalContentAlignmentProperty); }
        set { SetValue(HorizontalContentAlignmentProperty, value); }
    }

    public static readonly DependencyProperty HorizontalContentAlignmentProperty =
        DependencyProperty.Register("HorizontalContentAlignment", typeof(HorizontalAlignment), typeof(AlignableWrapPanel), new FrameworkPropertyMetadata(HorizontalAlignment.Left, FrameworkPropertyMetadataOptions.AffectsArrange));

    protected override Size MeasureOverride(Size constraint)
    {
        Size curLineSize = new Size();
        Size panelSize = new Size();

        UIElementCollection children = base.Children;

        for (int i = 0; i < children.Count; i++)
        {
            UIElement child = children[i] as UIElement;

            // Flow passes its own constraint to children
            child.Measure(constraint);
            Size sz = child.DesiredSize;

            if (curLineSize.Width + sz.Width > constraint.Width) //need to switch to another line
            {
                panelSize.Width = Math.Max(curLineSize.Width, panelSize.Width);
                panelSize.Height += curLineSize.Height;
                curLineSize = sz;

                if (sz.Width > constraint.Width) // if the element is wider then the constraint - give it a separate line                    
                {
                    panelSize.Width = Math.Max(sz.Width, panelSize.Width);
                    panelSize.Height += sz.Height;
                    curLineSize = new Size();
                }
            }
            else //continue to accumulate a line
            {
                curLineSize.Width += sz.Width;
                curLineSize.Height = Math.Max(sz.Height, curLineSize.Height);
            }
        }

        // the last line size, if any need to be added
        panelSize.Width = Math.Max(curLineSize.Width, panelSize.Width);
        panelSize.Height += curLineSize.Height;

        return panelSize;
    }

    protected override Size ArrangeOverride(Size arrangeBounds)
    {
        int firstInLine = 0;
        Size curLineSize = new Size();
        double accumulatedHeight = 0;
        UIElementCollection children = this.Children;

        for (int i = 0; i < children.Count; i++)
        {
            Size sz = children[i].DesiredSize;

            if (curLineSize.Width + sz.Width > arrangeBounds.Width) //need to switch to another line
            {
                ArrangeLine(accumulatedHeight, curLineSize, arrangeBounds.Width, firstInLine, i);

                accumulatedHeight += curLineSize.Height;
                curLineSize = sz;

                if (sz.Width > arrangeBounds.Width) //the element is wider then the constraint - give it a separate line                    
                {
                    ArrangeLine(accumulatedHeight, sz, arrangeBounds.Width, i, ++i);
                    accumulatedHeight += sz.Height;
                    curLineSize = new Size();
                }
                firstInLine = i;
            }
            else //continue to accumulate a line
            {
                curLineSize.Width += sz.Width;
                curLineSize.Height = Math.Max(sz.Height, curLineSize.Height);
            }
        }

        if (firstInLine < children.Count)
            ArrangeLine(accumulatedHeight, curLineSize, arrangeBounds.Width, firstInLine, children.Count);

        return arrangeBounds;
    }

    private void ArrangeLine(double y, Size lineSize, double boundsWidth, int start, int end)
    {
        double x = 0;
        if (this.HorizontalContentAlignment == HorizontalAlignment.Center)
        {
            x = (boundsWidth - lineSize.Width) / 2;
        }
        else if (this.HorizontalContentAlignment == HorizontalAlignment.Right)
        {
            x = (boundsWidth - lineSize.Width);
        }

        UIElementCollection children = Children;
        for (int i = start; i < end; i++)
        {
            UIElement child = children[i];
            var rect = new System.Windows.Rect(x, y, child.DesiredSize.Width, lineSize.Height);
            child.Arrange(rect);
            x += child.DesiredSize.Width;
        }
    }
}

Answer 6

أنا في حاجة إلى WrapPanel التي يمكن أن تمتد محتواه ، مستندا في ذلك على https://stackoverflow.com/a/7747002/121122 وبعض تافه خطرت لي هذه:

public class AlignableWrapPanel : Panel
{
    public HorizontalAlignment HorizontalContentAlignment
    {
        get => (HorizontalAlignment)GetValue(HorizontalContentAlignmentProperty);
        set => SetValue(HorizontalContentAlignmentProperty, value);
    }

    public static readonly DependencyProperty HorizontalContentAlignmentProperty = DependencyProperty.Register(
        nameof(HorizontalContentAlignment),
        typeof(HorizontalAlignment),
        typeof(AlignableWrapPanel),
        new FrameworkPropertyMetadata(HorizontalAlignment.Left, FrameworkPropertyMetadataOptions.AffectsArrange));

    protected override Size MeasureOverride(Size constraint)
    {
        var curLineSize = new Size();
        var panelSize = new Size();

        var children = InternalChildren;

        for (var i = 0; i < children.Count; i++)
        {
            var child = children[i];

            // flow passes its own constraint to children
            child.Measure(constraint);
            var sz = child.DesiredSize;

            if (curLineSize.Width + sz.Width > constraint.Width) // need to switch to another line
            {
                panelSize.Width = Math.Max(curLineSize.Width, panelSize.Width);
                panelSize.Height += curLineSize.Height;
                curLineSize = sz;

                if (sz.Width > constraint.Width) // if the element is wider then the constraint - give it a separate line                    
                {
                    panelSize.Width = Math.Max(sz.Width, panelSize.Width);
                    panelSize.Height += sz.Height;
                    curLineSize = new Size();
                }
            }
            else // continue to add to the line
            {
                curLineSize.Width += sz.Width;
                curLineSize.Height = Math.Max(sz.Height, curLineSize.Height);
            }
        }

        // the last line size, if any need to be added
        panelSize.Width = Math.Max(curLineSize.Width, panelSize.Width);
        panelSize.Height += curLineSize.Height;

        return panelSize;
    }

    protected override Size ArrangeOverride(Size arrangeBounds)
    {
        var firstInLine = 0;
        var curLineSize = new Size();
        var accumulatedHeight = 0D;
        var children = InternalChildren;

        for (var i = 0; i < children.Count; i++)
        {
            var desiredSize = children[i].DesiredSize;

            if (curLineSize.Width + desiredSize.Width > arrangeBounds.Width) // need to switch to another line
            {
                ArrangeLine(accumulatedHeight, curLineSize, arrangeBounds.Width, firstInLine, i);

                accumulatedHeight += curLineSize.Height;
                curLineSize = desiredSize;

                if(
                    desiredSize.Width > arrangeBounds.Width || 
                    children[i] is FrameworkElement element && element.HorizontalAlignment == HorizontalAlignment.Stretch)
                {
                    // the element is wider then the constraint or it stretches - give it a separate line
                    ArrangeLine(accumulatedHeight, desiredSize, arrangeBounds.Width, i, ++i);
                    accumulatedHeight += desiredSize.Height;
                    curLineSize = new Size();
                }
                firstInLine = i;
            }
            else // continue to add to the line
            {
                curLineSize.Width += desiredSize.Width;
                curLineSize.Height = Math.Max(desiredSize.Height, curLineSize.Height);
            }
        }

        if (firstInLine < children.Count)
        {
            ArrangeLine(accumulatedHeight, curLineSize, arrangeBounds.Width, firstInLine, children.Count);
        }

        return arrangeBounds;
    }

    private void ArrangeLine(double y, Size lineSize, double boundsWidth, int start, int end)
    {
        var children = InternalChildren;

        var x = 0D;
        if (HorizontalContentAlignment == HorizontalAlignment.Center)
        {
            x = (boundsWidth - lineSize.Width) / 2;
        }
        else if (HorizontalContentAlignment == HorizontalAlignment.Right)
        {
            x = boundsWidth - lineSize.Width;
        }

        var stretchChildren = new List<UIElement>();
        for (var i = start; i < end; i++)
        {
            var child = children[i];
            if (child is FrameworkElement element && element.HorizontalAlignment == HorizontalAlignment.Stretch)
            {
                stretchChildren.Add(child);
            }
        }

        var spaceAvailableForStretchChildren = boundsWidth - lineSize.Width;
        var spaceAvailablePerStretchChild = 0D;
        if (stretchChildren.Any())
        {
            x = 0; // all available space will be filled so start at 0
            spaceAvailablePerStretchChild = spaceAvailableForStretchChildren / stretchChildren.Count;
            spaceAvailablePerStretchChild = spaceAvailablePerStretchChild >= 0 ? spaceAvailablePerStretchChild : 0;
        }

        for (var i = start; i < end; i++)
        {
            var child = children[i];
            double itemWidth;
            if(stretchChildren.Contains(child))
            {
                itemWidth = child.DesiredSize.Width + spaceAvailablePerStretchChild;
            }
            else
            {
                itemWidth = child.DesiredSize.Width;
            }

            child.Arrange(new Rect(x, y, itemWidth, lineSize.Height));
            x += itemWidth;
        }
    }
}