OnlineMonitorSystem/HandyControl/HandyControl_Shared/Controls/Attach/ImageAttach.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace HandyControl.Controls;

public class ImageAttach
{
    public static readonly DependencyProperty SourceFailedProperty = DependencyProperty.RegisterAttached(
        "SourceFailed", typeof(ImageSource), typeof(ImageAttach), new FrameworkPropertyMetadata(default(ImageSource), FrameworkPropertyMetadataOptions.Inherits, OnSourceFailedChanged));

    private static void OnSourceFailedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is Image image)
        {
            if (e.NewValue is ImageSource)
            {
                image.ImageFailed += Image_ImageFailed;
            }
            else
            {
                image.ImageFailed -= Image_ImageFailed;
            }
        }
    }

    private static void Image_ImageFailed(object sender, ExceptionRoutedEventArgs e)
    {
        if (sender is Image image)
        {
            image.SetCurrentValue(Image.SourceProperty, GetSourceFailed(image));
            image.ImageFailed -= Image_ImageFailed;
        }
    }

    public static void SetSourceFailed(DependencyObject element, ImageSource value)
        => element.SetValue(SourceFailedProperty, value);

    public static ImageSource GetSourceFailed(DependencyObject element)
        => (ImageSource) element.GetValue(SourceFailedProperty);
}