#region 检索手机扩展卡类

 public class EnumFlashCard
 {
  public EnumFlashCard()
  {
   //
   // TODO: Add constructor logic here
   //
  }

  // Flash-card search functions.
  [DllImport("note_prj.dll", EntryPoint="FindFirstFlashCard")]
  public static extern IntPtr YD_FindFirstFlashCard (IntPtr lpFindFlashData);
  [DllImport("note_prj.dll", EntryPoint="FindNextFlashCard")]
  public static extern int YD_FindNextFlashCard (IntPtr hFlashCard, IntPtr lpFindFlashData);
  [DllImport("coredll.dll", EntryPoint="FindClose")]
  public static extern int YD_FindClose (IntPtr hFindFile);

  const int MAX_PATH = 260;

  public struct FILETIME
  {
   public int dwLowDateTime;
   public int dwHighDateTime;
  };
     
  public struct WIN32_FIND_DATA
  {
   public int dwFileAttributes;
   public FILETIME ftCreationTime;
   public FILETIME ftLastAccessTime;
   public FILETIME ftLastWriteTime;
   public int nFileSizeHigh;
   public int nFileSizeLow;
   public int dwOID;
   public String cFileName;
  };

  // Memory allocation functions.
  public const int LMEM_FIXED = 0x0000;
  [DllImport("coredll.dll")]
  public static extern IntPtr LocalAlloc (int uFlags, int uBytes);
  [DllImport("coredll.dll")]
  public static extern IntPtr LocalFree (IntPtr hMem);

  public static int INVALID_HANDLE_VALUE = -1;

  //--------------------------------------------------------
  // Buffer needed for find-flash-card functions
  //--------------------------------------------------------
  static IntPtr pFindData = IntPtr.Zero;

  private static void CopyIntPtr_to_WIN32_FIND_DATA(IntPtr pIn, ref WIN32_FIND_DATA pffd)
  {
   // Handy values for incrementing IntPtr pointer.
   int i = 0;
   int cbInt = Marshal.SizeOf(i);
   FILETIME ft = new FILETIME();
   int cbFT = Marshal.SizeOf(ft);

   // int dwFileAttributes
   pffd.dwFileAttributes = Marshal.ReadInt32(pIn);
   pIn = (IntPtr)((int)pIn + cbInt);

   // FILETIME ftCreationTime;
   Marshal.PtrToStructure(pIn, pffd.ftCreationTime);
   pIn = (IntPtr)((int)pIn + cbFT);

   // FILETIME ftLastAccessTime;
   Marshal.PtrToStructure(pIn, pffd.ftLastAccessTime);
   pIn = (IntPtr)((int)pIn + cbFT);

   // FILETIME ftLastWriteTime;
   Marshal.PtrToStructure(pIn, pffd.ftLastWriteTime);
   pIn = (IntPtr)((int)pIn + cbFT);

   // int nFileSizeHigh;
   pffd.nFileSizeHigh = Marshal.ReadInt32(pIn);
   pIn = (IntPtr)((int)pIn + cbInt);

   // int nFileSizeLow;
   pffd.nFileSizeLow = Marshal.ReadInt32(pIn);
   pIn = (IntPtr)((int)pIn + cbInt);

   // int dwOID;
   pffd.dwOID = Marshal.ReadInt32(pIn);
   pIn = (IntPtr)((int)pIn + cbInt);

   // String cFileName;
   pffd.cFileName = Marshal.PtrToStringUni(pIn);
  }

  // FindFirstFlashCard
  public static IntPtr FindFirstFlashCard (ref WIN32_FIND_DATA pffd)
  {
   IntPtr hFF = new IntPtr(INVALID_HANDLE_VALUE);

   // Allocate a block large enough for WIN32_FIND_DATA
   pFindData = LocalAlloc(LMEM_FIXED,560);
   if (pFindData == IntPtr.Zero)
    goto ErrorExit;

   hFF = YD_FindFirstFlashCard(pFindData);
   if (hFF.ToInt32() != INVALID_HANDLE_VALUE)
   {
    CopyIntPtr_to_WIN32_FIND_DATA(pFindData, ref pffd);
   }

   ErrorExit:          
    return hFF;
  }

  // FindNextFlashCard
  public static bool  FindNextFlashCard (IntPtr hFlashCard, ref WIN32_FIND_DATA pffd)
  {
   bool bRet = false;

   if (pFindData == IntPtr.Zero)
    goto ErrorExit;

   int bMore = YD_FindNextFlashCard(hFlashCard, pFindData);
   if (bMore != 0)
   {
    CopyIntPtr_to_WIN32_FIND_DATA(pFindData, ref pffd);
    bRet = true;
   }

   ErrorExit:          
    return bRet;
  }

  //FindClose
  public static bool FindClose (IntPtr hFindFile)
  {
   bool bRet = (YD_FindClose(hFindFile) != 0);

   // Free the memory we allocated.
   if (pFindData != IntPtr.Zero)
   {
    LocalFree(pFindData);
    pFindData = IntPtr.Zero;
   }
        
   return bRet;
  }

 }

 #endregion

 //调用实例

      IntPtr hffc = new IntPtr(EnumFlashCard.INVALID_HANDLE_VALUE);
      EnumFlashCard.WIN32_FIND_DATA wfd = new EnumFlashCard.WIN32_FIND_DATA();

      string firstcardname="";//手机内存卡名,可能为空
      string nextcardname="";//扩展卡名

      hffc = EnumFlashCard.FindFirstFlashCard (ref wfd);
      if(hffc.ToInt32() != EnumFlashCard.INVALID_HANDLE_VALUE)
       firstcardname=wfd.cFileName;

      if(EnumFlashCard.FindNextFlashCard(hffc, ref wfd))
       nextcardname=wfd.cFileName;

     //关闭非托管代码，释放内存
      if(hffc.ToInt32() != EnumFlashCard.INVALID_HANDLE_VALUE)
      {
       EnumFlashCard.FindClose(hffc);
       hffc = new IntPtr(EnumFlashCard.INVALID_HANDLE_VALUE);
      }