Hi,
Du kannst einfach SelectedIndex auf die Position des eingefügten Objektes setzen, z.B. so:
XAML:
<Window x:Class="WpfApp1CS.Window36"
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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp1CS"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
mc:Ignorable="d"
Title="Window36" Height="300" Width="300">
<Window.Resources>
<local:Window36VM x:Key="vm"/>
</Window.Resources>
<Grid DataContext="{StaticResource vm}">
<ListBox ItemsSource="{Binding Liste}" AllowDrop="True" DisplayMemberPath="Info">
<i:Interaction.Behaviors>
<local:Window36Behavior/>
</i:Interaction.Behaviors>
</ListBox>
</Grid>
</Window>
Dazu der ViewModel und die anderen Klassen:
using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Interactivity;
namespace WpfApp1CS
{
public class Window36VM
{
CollectionViewSource cvs = new CollectionViewSource();
public ObservableCollection<Window36Data> Collection = new ObservableCollection<Window36Data>();
public ICollectionView Liste
{
get
{
if (cvs.Source == null)
{
for (int i = 1; i < 20; i++) Collection.Add(new Window36Data() { Info = $"Zeile {i}" });
cvs.Source = Collection;
}
return cvs.View;
}
}
}
public class Window36Data
{
public Guid ID { get; } = Guid.NewGuid();
public string Info { get; set; }
}
public class Window36Behavior : Behavior<ListBox>
{
protected override void OnAttached()
{
AssociatedObject.PreviewMouseLeftButtonDown += AssociatedObject_PreviewMouseLeftButtonDown;
AssociatedObject.DragEnter += AssociatedObject_DragEnter;
AssociatedObject.Drop += AssociatedObject_Drop;
}
protected override void OnDetaching()
{
AssociatedObject.PreviewMouseLeftButtonDown -= AssociatedObject_PreviewMouseLeftButtonDown;
AssociatedObject.DragEnter -= AssociatedObject_DragEnter;
AssociatedObject.Drop -= AssociatedObject_Drop;
}
private void AssociatedObject_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
TextBlock tb = AssociatedObject.InputHitTest(e.GetPosition(AssociatedObject)) as TextBlock;
if (tb == null) return;
string data = (tb.DataContext as Window36Data).ID.ToString();
DragDrop.DoDragDrop(AssociatedObject, data, DragDropEffects.Move);
}
private void AssociatedObject_DragEnter(object sender, DragEventArgs e) => e.Effects = DragDropEffects.Move;
private void AssociatedObject_Drop(object sender, DragEventArgs e)
{
// ViewModel
Window36VM vm = AssociatedObject.DataContext as Window36VM;
if (vm == null) return;
// zu verschiebendes Object
Guid id1 = Guid.Parse(e.Data.GetData(DataFormats.Text).ToString());
Window36Data obj1 = (from item in vm.Collection where item.ID == id1 select item).FirstOrDefault();
vm.Collection.Remove(obj1);
// Ziel-Objekt
TextBlock tb = AssociatedObject.InputHitTest(e.GetPosition(AssociatedObject)) as TextBlock;
if (tb == null) return;
Guid id2 = (tb.DataContext as Window36Data).ID;
for (int i = 0; i < vm.Collection.Count; i++)
{
if (vm.Collection[i].ID == id2)
{
vm.Collection.Insert(i + 1, obj1);
AssociatedObject.SelectedIndex = i + 1;
break;
}
}
}
}
}
--
Viele Grüsse
Peter Fleischer (ehem. MVP)
Meine Homepage mit Tipps und Tricks
