Wpf Image Control blocks the file

When you bind the Image.Source property to an Uri (or a string, from which an Uri is created internally), WPF uses a built-in type converter that creates a BitmapFrame from the Uri.

If the Uri contains a path to a local file, the BitmapFrame keeps the file open, as long as it is existing. This may be longer than it is actually used in your application, because it may by cached by WPF.

When you need to be able to delete the file that an image was loaded from, you should always use your FileObject approach, but it should look like this:

public ImageSource Image
{
    get
    {
        ...
        var bi = new BitmapImage();
        using (var fs = new FileStream(FileName, FileMode.Open, FileAccess.Read))
        {
            bi.BeginInit();
            bi.CacheOption = BitmapCacheOption.OnLoad;
            bi.StreamSource = fs;
            bi.EndInit();
        }
        return bi;
    }
}

Or like this:

public ImageSource Image
{
    get
    {
        using (var fs = new FileStream(FileName, FileMode.Open, FileAccess.Read))
        {
            return BitmapFrame.Create(
                fs, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
        }
    }
}

Or you bind to the FileName property with a binding converter that creates a BitmapImage or BitmapFrame as shown above.