Excel喜歡在Wpf中拖動選項itemscontrol

Question

我正在尋找在Wpf項目控件中的選擇矩形，就像在MS Excel中一樣。我已經看過裝飾者和adoners，但得到了一點幫助。我需要圍繞單元格的厚邊框，我選擇使用鼠標（查看截圖）

Answer 1

我對你的解決方案，這似乎只有一個附加屬性，爲您附加到項目工作得相當好控件，如列表框。 代碼通過檢查它們是否通過索引連續進行猜測，以判斷所選項目是否連續。說一個統計網格的行數不起作用，但這應該讓你開始。

using System.Collections.Generic; 
using System.Linq; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Controls.Primitives; 
using System.Windows.Documents; 
using System.Windows.Media; 

namespace WpfApplication2 
{ 
    /// <summary> 
    /// Interaction logic for MainWindow.xaml 
    /// </summary> 
    public partial class MainWindow : Window 
    { 
     public MainWindow() 
     { 
      InitializeComponent(); 
     } 
    } 
    public sealed class SelectionAdorner : Adorner 
    { 
     private static readonly Dictionary<Selector, SelectionAdorner> _dictionary = new Dictionary<Selector, SelectionAdorner>(); 
     private static readonly Pen _pen = CreatePen(); 
     public static readonly DependencyProperty UseAdornerProperty = DependencyProperty.RegisterAttached("UseAdorner", typeof(bool), typeof(SelectionAdorner), 
      new PropertyMetadata(OnUseAdornerChanged)); 
     static void AttachToScrollViewer(Selector selector) 
     { 
      ScrollViewer viewer = GetScrollViewer(selector); 
      if (viewer != null) 
      { 
       viewer.Tag = selector; 
       viewer.ScrollChanged += Viewer_ScrollChanged; 
      } 
     } 
     private static Pen CreatePen() 
     { 
      Pen pen = new Pen(Brushes.Black, 2.0); 
      pen.Freeze(); 
      return pen; 
     } 
     private static void DetachAdorner(Selector selector) 
     { 
      SelectionAdorner adorner; 
      if (_dictionary.TryGetValue(selector, out adorner)) 
      { 
       adorner._adornerLayer.Remove(adorner); 
       _dictionary.Remove(selector); 
      } 
     } 
     private static SelectionAdorner GetAdorner(Selector selector) 
     { 
      SelectionAdorner adorner; 
      if (!_dictionary.TryGetValue(selector, out adorner)) 
      { 
       _dictionary.Add(selector, adorner = new SelectionAdorner(selector)); 
      } 
      return adorner; 
     } 
     private static Rect GetBounds(Selector selector, UIElement containerElement) 
     { 
      Rect bounds = VisualTreeHelper.GetDescendantBounds(containerElement); 
      return new Rect(containerElement.TranslatePoint(bounds.TopLeft, selector), bounds.Size); 
     } 
     private static ScrollViewer GetScrollViewer(DependencyObject d) 
     { 
      List<DependencyObject> list = new List<DependencyObject>(); 
      foreach (DependencyObject child in Enumerable.Range(0, VisualTreeHelper.GetChildrenCount(d)).Select(index => VisualTreeHelper.GetChild(d, index))) 
      { 
       ScrollViewer viewer = child as ScrollViewer; 
       if (viewer != null) 
       { 
        return viewer; 
       } 
       list.Add(child); 
      } 
      return list.Select(GetScrollViewer).FirstOrDefault(viewer => viewer != null); 
     } 
     private static void OnUseAdornerChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) 
     { 
      Selector selector = d as Selector; 
      if (selector != null) 
      { 
       if (((bool)e.NewValue)) 
       { 
        selector.SelectionChanged += Selector_SelectionChanged; 
        if (!selector.IsLoaded) 
        { 
         selector.Loaded += Selector_Loaded; 
        } 
        else 
        { 
         AttachToScrollViewer(selector); 
        } 
        ProcessSelection(selector); 
       } 
       else 
       { 
        selector.SelectionChanged -= Selector_SelectionChanged; 
        if (!selector.IsLoaded) 
        { 
         selector.Loaded -= Selector_Loaded; 
        } 
        else 
        { 
         ScrollViewer viewer = GetScrollViewer(selector); 
         if (viewer != null) 
         { 
          viewer.ScrollChanged -= Viewer_ScrollChanged; 
         } 
        } 
        DetachAdorner(selector); 
       } 
      } 
     } 
     private static void ProcessSelection(Selector selector) 
     { 
      ListBox listBox = selector as ListBox; 
      if (listBox != null && listBox.SelectionMode != SelectionMode.Single) 
      { 
       if (listBox.SelectedItems.Count != 0) 
       { 
        object[] selectedItems = new object[listBox.SelectedItems.Count]; 
        listBox.SelectedItems.CopyTo(selectedItems, 0); 
        ProcessSelection(selector, selectedItems); 
        return; 
       } 
      } 
      else if (selector.SelectedItem != null) 
      { 
       ProcessSelection(selector, new[] { selector.SelectedItem }); 
       return; 
      } 
      DetachAdorner(selector); 
     } 
     private static void ProcessSelection(Selector selector, IEnumerable<object> selectedItems) 
     { 
      List<DependencyObject> containers = new List<DependencyObject>(); 
      List<int> indices = new List<int>(); 
      foreach (DependencyObject container in selectedItems 
       .Select(selectedItem => selector.ItemContainerGenerator.ContainerFromItem(selectedItem)) 
       .Where(container => container != null)) 
      { 
       int containerIndex = selector.ItemContainerGenerator.IndexFromContainer(container); 
       int index = indices.BinarySearch(containerIndex); 
       containers.Insert(~index, container); 
       indices.Insert(~index, containerIndex); 
      } 
      for (int i = 1; i < indices.Count; i++) 
      { 
       if (indices[i] != (indices[i - 1] + 1)) 
       { 
        // Not contiguous 
        DetachAdorner(selector); 
        return; 
       } 
      } 
      Rect bounds = GetBounds(selector, (UIElement)containers[0]); 
      for (int i = 1; i < containers.Count; i++) 
      { 
       bounds.Union(GetBounds(selector, (UIElement)containers[i])); 
      } 
      GetAdorner(selector).Update(bounds); 
     } 
     static void Selector_Loaded(object sender, RoutedEventArgs e) 
     { 
      var selector = (Selector)sender; 
      AttachToScrollViewer(selector); 
      selector.Loaded -= Selector_Loaded; 
     } 
     private static void Selector_SelectionChanged(object sender, SelectionChangedEventArgs e) 
     { 
      ProcessSelection((Selector)sender); 
     } 
     static void Viewer_ScrollChanged(object sender, ScrollChangedEventArgs e) 
     { 
      ProcessSelection((Selector)((FrameworkElement)sender).Tag); 
     } 
     public static bool GetUseAdorner(Selector control) 
     { 
      return (bool)control.GetValue(UseAdornerProperty); 
     } 
     public static void SetUseAdorner(Selector control, bool useAdorner) 
     { 
      control.SetValue(UseAdornerProperty, useAdorner); 
     } 
     private readonly AdornerLayer _adornerLayer; 
     private Rect _bounds; 
     private void Update(Rect bounds) 
     { 
      this._bounds = bounds; 
      this.InvalidateVisual(); 
     } 
     protected override void OnRender(DrawingContext drawingContext) 
     { 
      drawingContext.DrawRectangle(null, _pen, this._bounds); 
     } 
     private SelectionAdorner(Selector selector) 
      : base(selector) 
     { 
      if ((_adornerLayer = AdornerLayer.GetAdornerLayer(selector)) != null) 
      { 
       _adornerLayer.Add(this); 
      } 
     } 
    } 
} 

<Window x:Class="WpfApplication2.MainWindow" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     xmlns:sl="clr-namespace:System.Linq;assembly=System.Core" 
     xmlns:s="clr-namespace:System;assembly=mscorlib" 
     xmlns:WpfApplication2="clr-namespace:WpfApplication2" Title="MainWindow" Height="350" Width="525"> 
    <Window.Resources> 
     <ObjectDataProvider x:Key="Range" MethodName="Range" ObjectType="{x:Type sl:Enumerable}"> 
      <ObjectDataProvider.MethodParameters> 
       <s:Int32>0</s:Int32> 
       <s:Int32>40</s:Int32> 
      </ObjectDataProvider.MethodParameters> 
     </ObjectDataProvider> 
    </Window.Resources> 
    <Grid> 
     <ListBox ItemsSource="{Binding Source={StaticResource Range}}" SelectionMode="Extended" HorizontalContentAlignment="Stretch" 
        WpfApplication2:SelectionAdorner.UseAdorner="true"> 
      <ListBox.ItemsPanel> 
       <ItemsPanelTemplate> 
        <VirtualizingStackPanel Orientation="Horizontal" IsItemsHost="True" /> 
       </ItemsPanelTemplate> 
      </ListBox.ItemsPanel> 
      <ListBox.ItemContainerStyle> 
       <Style TargetType="{x:Type ListBoxItem}"> 
        <Setter Property="Margin" Value="3" /> 
       </Style> 
      </ListBox.ItemContainerStyle> 
     </ListBox> 
    </Grid> 
</Window>