WPF TranslateTransform +=deltaX +=deltaY

<Window x:Class="WpfApp136.MainWindow"
        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:WpfApp136" MouseDown="img_MouseDown" 
        MouseUp="img_MouseUp" MouseMove="img_MouseMove"
        mc:Ignorable="d" WindowState="Maximized"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="200"/>
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <ListBox x:Name="lbx" Grid.Column="0" SelectionChanged="lbx_SelectionChanged">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Image Source="{Binding Content,RelativeSource={RelativeSource AncestorType=ListBoxItem}}"
                          Width="200" Height="500" RenderOptions.BitmapScalingMode="LowQuality" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <Image Grid.Column="1" x:Name="img" ClipToBounds="True"
               Source="{Binding SelectedItem,ElementName=lbx,Mode=TwoWay}" 
               RenderOptions.BitmapScalingMode="HighQuality" RenderOptions.EdgeMode="Aliased"
               MouseDown="img_MouseDown"
               MouseMove="img_MouseMove" MouseUp="img_MouseUp">
            <Image.RenderTransform>
                <TranslateTransform x:Name="translater"/>
            </Image.RenderTransform>
        </Image>
    </Grid>
</Window>



//
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.IO;

namespace WpfApp136
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            var files = Directory.GetFiles(@"..\..\Images");
            lbx.ItemsSource = files; 
        }

        Point prePoint { get; set; }
        bool isMoving { get; set; } = false;
        private void img_MouseDown(object sender, MouseButtonEventArgs e)
        {
            prePoint = e.GetPosition(this);
        }

        private void img_MouseMove(object sender, MouseEventArgs e)
        {
            isMoving = true;
        }

        private void img_MouseUp(object sender, MouseButtonEventArgs e)
        {
            if(isMoving && e.ChangedButton== MouseButton.Left && e.ButtonState==MouseButtonState.Released)
            {
                Point pt = e.GetPosition(this);
                translater.X += pt.X - prePoint.X;
                translater.Y += pt.Y - prePoint.Y;
                isMoving = false;
            }
        }

        private void lbx_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            translater.X = 0;
            translater.Y=0;
        }
    }
}