c# - 无法将 AllowDrop、CanDragItems、CanReorderItems 属性添加到 Gridview

Question

作为练习，我正在尝试制作一个基本的浏览器。

我已经成功地将文件和/或(多个)文件夹拖放到我的资源管理器中，但希望能够拖放到 GridView 中。主要是将文件重新排序或拖动到 View 中的文件夹中。

在几次搜索中，我发现，首先，我应该将以下属性添加到我的 GridView 中:

CanReorderItems="True"
AllowDrop="True"
CanDragItems="True"

但是 VS 给我以下错误:

在类型“GridView”中找不到属性“CanDragItems”。

我见过多个将这些属性添加到 GridView 的示例。我一定在这里遗漏了一些明显的东西。

我的XAML代码如下:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title=""
        Height="350"
        Width="525"
        MinHeight="200"
        MinWidth="200">
    <Grid>
        <Grid   AllowDrop="True"
                Drop="Grid_Drop">
            <Grid.RowDefinitions>
                <RowDefinition Height="26" />
                <RowDefinition />
            </Grid.RowDefinitions>
            <ToolBar Grid.Row="0"
                     Grid.Column="0"
                     HorizontalAlignment="Stretch"
                     Name="toolBar1"
                     VerticalAlignment="Stretch">
                <Button  HorizontalAlignment="Left"
                         Name="btnFolderUp"
                         VerticalAlignment="Stretch"
                         Click="btnFolderUp_Click">
                    <Image Source="images\folder-up.png" />
                </Button>
                <Button  HorizontalAlignment="Left"
                         Name="btnFolderNew"
                         VerticalAlignment="Stretch"
                         Click="btnFolderNew_Click">
                    <Image Source="images\folder-new.png" />
                </Button>
            </ToolBar>
            <ListView Grid.Row="1"
                      Grid.Column="0"
                      HorizontalAlignment="Stretch"
                      VerticalAlignment="Stretch"
                      Name="lvDataBinding"
                      MouseDoubleClick="lvDataBinding_MouseDoubleClick">
                <ListView.View>
                    <GridView CanReorderItems="True"
                              AllowDrop="True"
                              CanDragItems="True">
                        <GridView.Columns>
                            <GridViewColumn>
                                <GridViewColumnHeader Content="Name"
                                                      Name="Name"
                                                      Click="GridViewColumnHeader_Click" />
                                <GridViewColumn.CellTemplate>
                                    <DataTemplate>
                                        <StackPanel Orientation="Horizontal">
                                            <Image Source="{Binding Path=fileIcon}"
                                                   Margin="3,3,3,3"
                                                   Width="15"
                                                   Height="15" />
                                            <TextBlock Text="{Binding Path=Name}"
                                                       HorizontalAlignment="Stretch"
                                                       VerticalAlignment="Stretch" />
                                        </StackPanel>
                                    </DataTemplate>
                                </GridViewColumn.CellTemplate>
                            </GridViewColumn>
                            <GridViewColumn>
                                <GridViewColumnHeader Content="DateCreated"
                                                      Name="DateCreated"
                                                      Click="GridViewColumnHeader_Click" />
                                <GridViewColumn.CellTemplate>
                                    <DataTemplate>
                                        <StackPanel Orientation="Horizontal">
                                            <TextBlock Text="{Binding Path=DateCreated}"
                                                       HorizontalAlignment="Stretch"
                                                       VerticalAlignment="Stretch" />
                                        </StackPanel>
                                    </DataTemplate>
                                </GridViewColumn.CellTemplate>
                            </GridViewColumn>
                        </GridView.Columns>
                    </GridView>
                </ListView.View>
            </ListView>
        </Grid>
    </Grid>
</Window>

Answer 1

问题与WPF相关。
所以 ListView 上只存在 AllowDrop="true"。

为了支持拖放:

1. 必须更改 ListView 项的样式:

      <Window.Resources>
       <Style x:Key="ListViewItemStyle1" TargetType="{x:Type ListViewItem}">
           <EventSetter Event="ListBoxItem.DragOver" Handler="ListBoxItemDragOver"/>
           <EventSetter Event="ListBoxItem.Drop" Handler="ListBoxItemDrop"/>
           <EventSetter Event="ListBoxItem.PreviewMouseMove" Handler="ListBoxItemPreviewMouseMove"/>
       </Style>
   </Window.Resources>
   

在 ListView 声明中，引用样式:

        <ListView AllowDrop="True"
                  ItemContainerStyle="{DynamicResource ListViewItemStyle1}"
                  Name="lvDataBinding"
                  Drop="lvDataBinding_Drop"
                  DragOver="lvDataBinding_DragOver"
                  DragEnter="lvDataBinding_DragEnter">

1. 必须实现 ListViewItems 的事件:

   private FileData sourceFileData;
   private void ListBoxItemPreviewMouseMove(object sender, MouseEventArgs e)
   {
       if (e.LeftButton != MouseButtonState.Pressed)
           return;
       var listboxItem = sender as ListBoxItem;
       if (listboxItem == null)
           return;
       sourceFileData = listboxItem.DataContext as FileData;
       if (sourceFileData == null)
           return;
       var data = new DataObject();
       data.SetData(sourceFileData);
       // provide some data for DnD in other applications (Word, ...)
       data.SetData(DataFormats.StringFormat, sourceFileData.ToString());
       DragDropEffects effect = DragDrop.DoDragDrop(listboxItem, data, DragDropEffects.Move | DragDropEffects.Copy);
   }
   private void ListBoxItemDrop(object sender, DragEventArgs e)
   {
       // support application data source and explorer file
       if (!e.Data.GetDataPresent(typeof(FileData)) && !e.Data.GetDataPresent(DataFormats.FileDrop))
           return;
       var listBoxItem = sender as ListBoxItem;
       if (listBoxItem == null)
           return;
       var targetFile = listBoxItem.DataContext as FileData;
       if (targetFile != null)
       {
           int targetIndex = files.IndexOf(targetFile);
           int sourceIndex = files.IndexOf(sourceFileData);
           double y = e.GetPosition(listBoxItem).Y;
           bool insertAfter = y > listBoxItem.ActualHeight / 2;
           if (insertAfter)
           {
               targetIndex++;
           }
           if (sourceIndex > targetIndex)
           {
               if (sourceIndex != -1)
                   files.RemoveAt(sourceIndex);
               files.Insert(targetIndex, sourceFileData);
           }
           else
           {
               files.Insert(targetIndex, sourceFileData);
               if (sourceIndex != -1)
                   files.RemoveAt(sourceIndex);
           }
       }
       e.Handled = true;
   }
   private void ListBoxItemDragOver(object sender, DragEventArgs e)
   {
       Debug.WriteLine(e.Effects);
       if (!e.Data.GetDataPresent(typeof(FileData)) && !e.Data.GetDataPresent(DataFormats.FileDrop))
       {
           e.Effects = DragDropEffects.None;
           e.Handled = true;
       }
   }
   

2. 必须实现一些事件以允许来自外部应用程序(例如 Explorer)的 DnD:

   private void lvDataBinding_DragOver(object sender, DragEventArgs e)
   {
       e.Handled = true;
   }
   private void lvDataBinding_DragEnter(object sender, DragEventArgs e)
   {
       if (e.Data.GetDataPresent(DataFormats.FileDrop))
       {
           String[] files =  e.Data.GetData(DataFormats.FileDrop) as String[];
           // that version only supports drop of a file, but could be augmented
           FileInfo fileInfo = new FileInfo(files[0]);
           sourceFileData = new FileData { DateCreated = fileInfo.CreationTime, Name = fileInfo.FullName };
           e.Handled = true;
       }
   }
   

3. 以上代码均为窗口代码。
   但是数据可能来自一个不错的项目中的 View 模型。
   这是数据的初始化:

   公共(public)部分类 MainWindow : Window{

   private ObservableCollection<FileData> files;
   public MainWindow()
   {
       files = new ObservableCollection<FileData>(
       new DirectoryInfo(@"e:\temp")
           .EnumerateFiles()
           .Select(fi => new FileData { DateCreated = fi.CreationTime, Name = fi.FullName })
       );
       InitializeComponent();
       lvDataBinding.ItemsSource = files;
   }  
   

这是一个显示代码的工作 VS 解决方案:
http://1drv.ms/1FNsK7n

问候