using Microsoft.Toolkit.Mvvm.ComponentModel;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Effects;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WPFDemo
{
    /// <summary>
    /// fyf 创建测试案例
    /// TheListBox.xaml 的交互逻辑
    /// </summary>
    public partial class TheListBox : UserControl
    {
        /// <summary>
        /// 数据model
        /// </summary>
        public ListBoxDataModel TheListBoxModel = new ListBoxDataModel();
        public TheListBox()
        {
            InitializeComponent();
            this.DataContext = TheListBoxModel;
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "张三", Ph = "125486545" });
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "李四", Ph = "125486545" });
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "王麻子", Ph = "125486545" });
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "二货", Ph = "125486545" });
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "张三1", Ph = "125486545" });
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "李四2", Ph = "125486545" });
            TheListBoxModel.ViewItems.Add(new ItemModel { Name = "王麻子3", Ph = "125486545" });
        }
        #region 移动事件
        /// <summary>
        /// 当前拖动子控件流
        /// </summary>
        private UIElement ChildElement;
        /// <summary>
        /// 当前拖拽子控件Item
        /// </summary>
        private ListBoxItem ChildListBoxItem;
        /// <summary>
        /// 是否已经按下
        /// </summary>
        private bool isDown = false;
        /// <summary>
        /// 当前拖动的Pop窗体
        /// </summary>
        private Popup DropPopup = null;
        /// <summary>
        /// 鼠标按下事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            try
            {
                //isDown变量是防止多次操作。
                if (isDown)
                {
                    isDown = false;
                    return;
                }

                ChildElement = (UIElement)sender;
                ChildElement.CaptureMouse();//设置了鼠标捕获，这样它可以不受到其它控件的影响。
                ChildListBoxItem = Utils.FindVisualParent<ListBoxItem>(VisualTreeHelper.HitTest(ChildElement, e.GetPosition(ChildElement)).VisualHit);

                //创建一个Pop,表明拖拽开始
                CreatePopup(ChildElement, e);

                isDown = true;
            }
            catch (Exception ex)
            {

            }
        }
        /// <summary>
        /// 鼠标抬起事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void lisbox_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            try
            {
                //鼠标未按下返回
                if (!isDown) return;

                isDown = false;

                //关闭Pop窗体
                if (this.DropPopup != null)
                {
                    this.DropPopup.IsOpen = false;
                    this.DropPopup.Child = null;
                    this.DropPopup = null;
                }

                //蒙层关闭,表明结束拖拽
                MoveListBoxStyle(null, false);

                //当控件具有鼠标捕获的话，则释放该捕获。
                ChildElement.ReleaseMouseCapture();
            }
            catch (Exception ex)
            {

            }
        }
        /// <summary>
        /// 鼠标移动事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ListView_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            try
            {
                if (isDown == false) return;

                if (e.LeftButton != MouseButtonState.Pressed)
                    lisbox_PreviewMouseLeftButtonUp(null, null);

                Point ptLeftUp = new Point(0, 0);
                Point ptRightDown = new Point(this.ActualWidth, this.ActualHeight);

                ptLeftUp = this.PointToScreen(ptLeftUp);
                ptRightDown = this.PointToScreen(ptRightDown);

                double y = e.GetPosition(this).Y;
                double x = e.GetPosition(this).X;

                if (DropPopup != null)//下面两句是设置Popup控件的位置除以2是想让鼠标在它的中心
                {
                    DropPopup.HorizontalOffset = ptLeftUp.X + x - ((FrameworkElement)ChildElement).ActualWidth / 2;
                    DropPopup.VerticalOffset = ptLeftUp.Y + y - ((FrameworkElement)ChildElement).ActualHeight / 2;
                }

                //蒙层打开,表明拖拽开始，设置透明度和显示状态
                MoveListBoxStyle(e, true);
            }
            catch (Exception ex)
            {
            }
        }
        /// <summary>
        /// 移动效果
        /// </summary>
        /// <param name="boxItem"></param>
        private void MoveListBoxStyle(MouseEventArgs e, bool isBool)
        {
            try
            {
                if (isBool)//为真，根据鼠标位置设置行透明度和显示状态
                {
                    //移动到某行减轻某行 暗黑
                    foreach (ListBoxItem item in Utils.FindVisualChildren<ListBoxItem>(listView))
                    {
                        if (item != ChildListBoxItem)//这就是其他控件
                        {
                            double item_width = item.ActualWidth;   //当前行宽
                            double item_height = item.ActualHeight; //当前行高
                            double item_x = e.GetPosition(item).X;  //鼠标相对当前行X位移
                            double item_y = e.GetPosition(item).Y;  //鼠标相对当前行Y位移

                            if (item_y <= item_height && item_y > 0 && item_x > 0 && item_x <= item_width)//鼠标进入哪一行,则将那一行变灰
                            {
                                item.Opacity = 0.5;
                                int lao_index = TheListBoxModel.ViewItems.IndexOf(item.Content as ItemModel);
                                int new_index = TheListBoxModel.ViewItems.IndexOf(ChildListBoxItem.Content as ItemModel);
                                TheListBoxModel.ViewItems.Move(lao_index, new_index);
                            }
                            else //鼠标没在哪一行，则保持原状
                            {
                                item.Opacity = 1;
                            }
                        }
                        else
                        {
                            item.Visibility = Visibility.Hidden;
                        }
                    }
                }
                else//为假 恢复所有行透明度和显示状态
                {
                    //移动到某行减轻某行 暗黑
                    foreach (ListBoxItem item in Utils.FindVisualChildren<ListBoxItem>(listView))
                    {
                        item.Opacity = 1;
                        item.Visibility = Visibility.Visible;
                    }
                }
            }
            catch (Exception ex)
            {
            }
        }
        /// <summary>
        /// 创建浮动窗口
        /// </summary>
        /// <param name="dragElement"></param>
        /// <param name="e"></param>
        private void CreatePopup(Visual dragElement, MouseButtonEventArgs e)
        {
            //使用PointToScreen函数可以将点转换为屏幕坐标
            //首先获取当前窗体的左上角和右下角两点的坐标
            Point ptLeftUp = new Point(0, 0);
            //转换获取到这个窗口相对于屏幕两个坐标
            ptLeftUp = this.PointToScreen(ptLeftUp);
            //获取myGrid的实际宽高，主
            double y = e.GetPosition(this).Y;
            double x = e.GetPosition(this).X;

            //拖拽Popup框
            this.DropPopup = new Popup();
            Border border = new Border();
            border.Margin = new Thickness(0, 0, 8, 8);
            DropShadowEffect effect = new DropShadowEffect();
            effect.Opacity = 1;
            effect.ShadowDepth = -14;
            effect.BlurRadius = 9;
            effect.Color = Color.FromArgb(100, 0, 0, 0);
            border.Effect = effect;

            //矩阵框
            Rectangle r = new Rectangle();
            r.Width = ((FrameworkElement)dragElement).ActualWidth;
            r.Height = ((FrameworkElement)dragElement).ActualHeight;
            r.Fill = new VisualBrush(dragElement);
            border.Child = r;
            this.DropPopup.Child = border;
            DropPopup.AllowsTransparency = true;
            DropPopup.HorizontalOffset = ptLeftUp.X + x - ((FrameworkElement)dragElement).ActualWidth / 2;
            DropPopup.VerticalOffset = ptLeftUp.Y + y - ((FrameworkElement)dragElement).ActualHeight / 2;
            this.DropPopup.IsOpen = true;
        }
        #endregion

    }
    /// <summary>
    /// 当前项数据Model
    /// </summary>
    public class ListBoxDataModel : ObservableObject
    {
        private ObservableCollection<ItemModel> _ViewItems;
        public ObservableCollection<ItemModel> ViewItems
        {
            get
            {
                return _ViewItems;
            }
            set
            {
                _ViewItems = value;
                OnPropertyChanged("ViewItems");
            }
        }
        public ListBoxDataModel()
        {
            ViewItems = new ObservableCollection<ItemModel>();
        }
    }
    /// <summary>
    /// 行数据Model
    /// </summary>
    public class ItemModel : ObservableObject
    {
        private string _Name;
        public string Name
        {
            get
            {
                return _Name;
            }
            set
            {
                _Name = value;
                OnPropertyChanged("Name");
            }
        }
        private string _Ph;
        public string Ph
        {
            get
            {
                return _Ph;
            }
            set
            {
                _Ph = value;
                OnPropertyChanged("Ph");
            }
        }
    }
    /// <summary>
    /// 帮助类
    /// </summary>
    internal static class Utils
    {
        /// <summary>
        /// 根据子元素查找父元素
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static T FindVisualParent<T>(DependencyObject obj) where T : class
        {
            while (obj != null)
            {
                if (obj is T)
                    return obj as T;

                obj = VisualTreeHelper.GetParent(obj);
            }
            return null;
        }
        /// <summary>
        /// 查询子控件
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static IEnumerable<T> FindVisualChildren<T>(DependencyObject depObj) where T : DependencyObject
        {
            if (depObj != null)
            {
                for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
                {
                    DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
                    if (child != null && child is T)
                    {
                        yield return (T)child;
                    }

                    foreach (T childOfChild in FindVisualChildren<T>(child))
                    {
                        yield return childOfChild;
                    }
                }
            }
        }
    }
}