方法在3310次成功后失败

我继承了以下扩展方法,该方法基于文件路径创建ImageSource对象

public static class ImageSourceExtensions
{
    [StructLayout(LayoutKind.Sequential)]
    public struct SHFILEINFO
    {
        public IntPtr hIcon;
        public int iIcon;
        public uint dwAttributes;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        public string szDisplayName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
        public string szTypeName;
    };

    public const uint SHGFI_ICON = 0x100;
    public const uint SHGFI_LARGEICON = 0x0;

    [DllImport("shell32.dll")]
    public static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, uint cbSizeFileInfo, uint uFlags);

    public static ImageSource GetIconFromFolder(this string filePath)
    {
        SHFILEINFO shinfo = new SHFILEINFO();
        SHGetFileInfo(filePath, 0, ref shinfo, (uint)Marshal.SizeOf(shinfo),
                SHGFI_ICON | SHGFI_LARGEICON);

        using (Icon i = Icon.FromHandle(shinfo.hIcon))
        {
            //Convert icon to a Bitmap source
            ImageSource img = Imaging.CreateBitmapSourceFromHIcon(
                                    i.Handle,
                                    new Int32Rect(0, 0, i.Width, i.Height),
                                    BitmapSizeOptions.FromEmptyOptions());

            return img;
        }
    }
}

'传递给图标的Win32句柄无效或错误 类型'

当使用 所有物

这个错误最初是在我的主应用程序中抛出的,每次都在不同的文件中。此后,我将该类提取到一个新项目中,通过单击按钮可以抛出相同的错误(在相同次数之后):

String path = @"C:\Generic Folder\Generic Document.pdf";

        for (int i = 0; i <4000; i++)
        {
            ImageSource img = path.GetIconFromFolder();
        }

有谁知道这件事的明显原因吗?