public void Focus(FileSystemInfoEx itemToFocus)
 {
     this.Dispatcher.BeginInvoke(DispatcherPriority.Background, new ThreadStart(delegate
     {
         FileListViewItemViewModel selectedVM = RootModel.CurrentDirectoryModel[itemToFocus];
         RootModel.CurrentDirectoryModel.UnselectAll();
         if (selectedVM != null)
         {
             selectedVM.IsSelected = true;
             if (this.View is GridView)
             {
                 this.ScrollIntoView(selectedVM);
             }
             else
             {
                 VirtualWrapPanel vwp = UITools.FindVisualChild <VirtualWrapPanel>(this);
                 int idx = Items.IndexOf(selectedVM);
                 if (vwp != null && idx != -1)
                 {
                     Rect rect = vwp.GetChildRect(idx);
                     if (vwp.Orientation == Orientation.Horizontal)
                     {
                         vwp.SetVerticalOffset(rect.Top);
                     }
                     else
                     {
                         vwp.SetHorizontalOffset(rect.Left);
                     }
                 }
             }
         }
     }));
 }
        private void ListViewFile_DropIn(object sender, DragEventArgs e)
        {
            var listView = sender as ListView;



            if (e.Data.GetDataPresent(typeof(System.Collections.IList)))
            {
                System.Collections.IList FileList = e.Data.GetData(typeof(System.Collections.IList)) as System.Collections.IList;

                foreach (var v in FileList)
                {
                    FileListViewItemViewModel flvivm = v as FileListViewItemViewModel;
                    if (flvivm != null)
                    {
                        //   this._Files.Add(new FileData(flvivm.FullName));
                        FileData fd = new FileData(flvivm.FullName);
                        if (!this.Files.Contains(fd))
                        {
                            this.Files.Add(fd);
                        }
                    }
                }
                //index为放置时鼠标下元素项的索引
            }
        }