static extern int SHQueryRecycleBin(string pszRootPath, ref SHQUERYRBINFO

    int hresult = SHQueryRecycleBin(string.Empty, ref sqrbi);

int hresult = SHQueryRecycleBin(@"C:\", ref sqrbi);

    [DllImport("shell32.dll")] public static extern int SHQueryRecycleBin(string pszRootPath, ref SHQUERYRBINFO pSHQueryRBInfo);

        SHQueryRecycleBin(String.Empty,ref shrb);