基于WPF实现ListBox拖动子项

<wd:window
    x:class="wpflistboxitemdrag.mainwindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:wpflistboxitemdrag"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:wd="https://github.com/wpfdevelopersorg/wpfdevelopers"
    title="wpf开发者 - listboxitemdrag"
    width="800"
    height="450"
    windowstartuplocation="centerscreen"
    mc:ignorable="d">
    <grid>
        <grid.columndefinitions>
            <columndefinition />
            <columndefinition />
        </grid.columndefinitions>
        <listbox
            x:name="listboxstart"
            allowdrop="true"
            borderthickness="1"
            itemssource="{binding itemsa}"
            previewmouseleftbuttondown="listboxstart_previewmouseleftbuttondown"
            previewmouseleftbuttonup="listboxstart_previewmouseleftbuttonup"
            previewmousemove="listboxstart_previewmousemove" />
        <canvas
            x:name="dragcanvas"
            grid.columnspan="2"
            panel.zindex="1000" />
        <listbox
            x:name="listboxend"
            grid.column="1"
            allowdrop="true"
            drop="listboxend_drop"
            itemssource="{binding itemsb}" />
    </grid>
</wd:window>

using system.collections.objectmodel;
using system.windows;
using system.windows.controls;
using system.windows.input;
using system.windows.media;

namespace wpflistboxitemdrag
{
    /// <summary>
    /// interaction logic for mainwindow.xaml
    /// </summary>
    public partial class mainwindow 
    {
        private bool isdragging;
        private listboxitem item;
        private listboxitem dragitem;
        private object data;
        public observablecollection<string> itemsa { get; set; }
        public observablecollection<string> itemsb { get; set; }

        public mainwindow()
        {
            initializecomponent();
            datacontext = this;
            itemsa = new() { "wpfdevelopersorg", "wpfdevelopers", "wpf开发者", "listbox", "listboxitem" };
            itemsb = new observablecollection<string>();
        }

        private void listboxstart_previewmouseleftbuttondown(object sender, mousebuttoneventargs e)
        {
            data = getlistboxitemdata(listboxstart, e.getposition(listboxstart));
            item = findvisualparent<listboxitem>((dependencyobject)e.originalsource);
            if (item != null)
                isdragging = true;
        }

        private t findvisualparent<t>(dependencyobject obj) where t : dependencyobject
        {
            while (obj != null)
            {
                if (obj is t)
                    return (t)obj;
                obj = visualtreehelper.getparent(obj);
            }
            return null;
        }

        private object getlistboxitemdata(listbox source, point point)
        {
            var element = source.inputhittest(point) as uielement;
            if (element != null)
            {
                var data = dependencyproperty.unsetvalue;
                while (data == dependencyproperty.unsetvalue)
                {
                    data = source.itemcontainergenerator.itemfromcontainer(element);

                    if (data == dependencyproperty.unsetvalue)
                        element = visualtreehelper.getparent(element) as uielement;
                    if (element == source)
                        return null;
                }
                if (data != dependencyproperty.unsetvalue)
                    return data;
            }
            return null;
        }

        private void listboxstart_previewmouseleftbuttonup(object sender, mousebuttoneventargs e)
        {
            if (data != null)
                dragdrop.dodragdrop(listboxstart, data, dragdropeffects.move);
            isdragging = false;
            if (dragitem != null)
            {
                dragcanvas.children.remove(dragitem);
                dragitem = null;
            }
        }

        private void listboxstart_previewmousemove(object sender, mouseeventargs e)
        {
            if (isdragging)
            {
                if (dragitem == null)
                {
                    dragitem = new listboxitem
                    {
                        content = item.content,
                        width = item.actualwidth,
                        height = item.actualheight,
                        background = brushes.gray,
                        contenttemplate = item.contenttemplate,
                        contenttemplateselector = item.contenttemplateselector,
                        style = item.style,
                        padding = item.padding,
                        opacity = .5,
                        ishittestvisible = false,
                    };
                    dragcanvas.children.add(dragitem);
                }
                var mousepos = e.getposition(dragcanvas);
                canvas.setleft(dragitem, mousepos.x - dragitem.actualwidth / 2);
                canvas.settop(dragitem, mousepos.y - dragitem.actualheight / 2);
            }
        }

        private void listboxend_drop(object sender, drageventargs e)
        {
            if (e.data.getdatapresent(typeof(string)))
            {
                var data = e.data.getdata(typeof(string)).tostring();
                itemsb.add(data);
                itemsa.remove(data.tostring());
            }
        }
    }
}