MARKUS

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Text;

using System.Threading.Tasks;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Media.Imaging;

namespace KCOM.Common

{

    public class LazyImage : DependencyObject

    {

        public static readonly DependencyProperty SourceProperty = DependencyProperty.Register("Source", typeof(string), typeof(LazyImage), new PropertyMetadata(null, OnSourcePropertyChanged));

        private static async void OnSourcePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)

        {

            Image imageControl = d as Image;

            string imagePath = e.NewValue as string;

            if (imageControl != null && imagePath != null && !string.IsNullOrEmpty(imagePath))

            {

                if (imageControl.IsLoaded && imageControl.ActualWidth > 0 && imageControl.ActualHeight > 0)

                {

                    await LoadImageAsync(imagePath, imageControl);

                }

                else

                {

                    RoutedEventHandler onImageControlLoaded = null;

                    onImageControlLoaded = async (sender, args) =>

                    {

                        imageControl.Loaded -= onImageControlLoaded;

                        await LoadImageAsync(imagePath, imageControl);

                    };

                    imageControl.Loaded += onImageControlLoaded;

                }

            }

        }

        public string Source

        {

            get { return (string)GetValue(SourceProperty); }

            set { SetValue(SourceProperty, value); }

        }

        private static async Task LoadImageAsync(string path, Image imageControl)

        {

            BitmapImage image = new BitmapImage();

            image.BeginInit();

            image.UriSource = new Uri(path);

            image.CacheOption = BitmapCacheOption.OnLoad;

            image.EndInit();

            await image.Dispatcher.BeginInvoke(new Action(() =>

            {

                imageControl.Source = image;

            }));

        }

    }

}