获取ISolatedStorage指定文件夹下所有子文件夹：
string[] folderlist;
IsolatedStorageFile iso = IsolatedStorageFile.GetUserStoreForApplication();
if(iso.DirectoryExists("folder"))
{
folderlist=iso.GetDirectoryNames(System.IO.Path.Combine("folder", "*"));
}
获取ISolatedStorage指定文件夹下的文件数：
string[] folderlist;
IsolatedStorageFile iso = IsolatedStorageFile.GetUserStoreForApplication();
if(iso.DirectoryExists(@"_Safety/"))
{
folderlist=iso.GetFileNames(@"_Safety/*.txt");
}