fce4vb_u.txt

建设银行计算机设备台帐程序计算机设备管理程序。其中包括一个网络文件传输示例

      2.0 Library Overview

      2.1 Dynamic Link Libraries

      FCE4VB includes both Win16 [FCE16] and Win32 [FCE32] dynamic link
      libraries (DLL). A DLL is characterized by the fact that it need not
      be loaded until required by an application program and that only one
      copy of the DLL is necessary regardless of the number of application
      programs that use it. Contrast this to a static library which is
      bound at link time to each and every application that uses it.

      2.2 Compiling Programs

      The example programs can be compiled from the Visual Basic
      development environment using the provided Visual Basic ".MAK" files,
      except for HELLO32, which uses a ".VBP" project file.  Choose
      "File", then "Open Project" from the main VB menu.

      The example program code is stored in VB 3.0 (WIN16) and VB 4.0
      (WIN32) formats. All project files (except Hello32) end in "16.MAK"
      (eg: FCEVER16.MAK) or "32.MAK" (eg: FCEVER32.MAK).

      After opening a project, VB 5.0 (and VB 6.0) users can save the
      project files in the VB 5.0 (or VB 6.0) format. When saving the
      example programs in VB version 5.0 or 6.0 format, answer "no" if
      asked to add the "Microsoft DAO 2.5 library".

      Compile and run FCEVER16 (or FCEVER32) as the first example.

      2.3 FCE4VB Class

      The FCE class "fceClass" (fceClass.cls) is a Visual Basic class
      wrapper for making calls to FCE32.DLL. The class name for each
      function is the same as the DLL function, except the leading "fce" is
      replaced by "f".

      Those functions that return strings do so by use of the "String
      Result" property.  Instantiate fceClass as any other class in VB:

         Dim X As New fceClass

      Also see the FCE4VB Reference Manual (FCE4VB_R.TXT), the example
      project "Hello32" and the file fceClass.txt.

      Use of fceClass is limited to Visual Basic 5.0 and above.













     FCE4VB Users Manual                                       Page 7

      3.0 Using the FCE Library

      The FCE library is divided into nine classes of functions, as
      follows:

      (1) The fceAttach and fceRelease functions are used to initialize and
      terminate the FCE system. fceAttach should be the very first FCE
      function called and fceRelease must be the last FCE function called.

      The first argument to fceAttach is the maximum number of threads that
      will be started. Use 1 for non-threaded applications. The first
      argument to most of the other FCE functions will be the channel (or
      thread) number. Up to 32 threads can be run simultaneously. Threads
      are numbered starting at 0. The second argument to fceAttach is the
      keycode.  See Section 4.3, "Key Codes".

      (3) The fceConnect function is used to connect to a FTP server. The
      fceClose function terminates the connection to the FTP server, after
      which another connection can be made. There should be one fceClose
      for every fceConnect.

      (4) The FCE functions fceSetLocalDir and fceGetLocalDir are used to
      set and display the local directory to be used for uploading and
      downloading files. They affect only the client computer. Nothing is
      sent or received from the FTP server.

      (5) The FCE function fceSetServerDir and fceGetServerDir are used to
      set and display the server directory from which all subsequent
      uploads and downloads will occur. The FCE functions fceMakeServerDir
      and fceDelServerDir are used to create and delete server directories.

      (6) The FCE function fceGetList is used to get a list of files from
      the FTP server. Both name lists and full directory lists can be
      retrieved.

      (7) The FCE function fceSetMode is used to set the transfer mode to
      either ASCII or binary for all subsequent file transfers.

      (8) The FCE functions fceGetFile and fcePutFile are used for
      downloading and uploading files. Note that the default is ASCII.

      (9) The FCE functions fceMakeServerDir and fceDelServer directory are
      used to create and remove directories on the server. Of course, this
      requires that you have permission. This is almost never the case when
      connecting as an anonymous user.













     FCE4VB Users Manual                                       Page 8

      4.0 Application Notes

      4.1 FTP Basics

      The FTP (File Transfer Protocol) protocol is defined by Internet
      document RFC 959. It is used to copy files between a FTP client and a
      FTP server over a TCP/IP connection using well known port 21.

      In order to connect to a FTP server, the server name (or IP address),
      the user name, and the user password must be known. This is known as
      private (or protected) access.

      Some FTP servers allow "anonymous" access, which is usually download
      only. The convention for anonymous access is to use the word
      "anonymous" for the user name, and the callers email address for the
      password. Many FTP servers will also accept "ftp" instead of
      "anonymous".

      FCE4VB supports "Passive" mode. Passive mode is often necessary in
      order to get past a firewall to access the server. Passive mode can
      be enabled by calling fceSetInteger(Chan, FCE_SET_PASSIVE, 1).

      4.2 Auto Dial

      To allow Dial-Up Networking (DUN) to dial up your ISP when you access
      the Winsock:

      (1) Open the DUN folder in "My Computer", and choose
      "Connections/Settings" from menu bar. Uncheck "prompt for information
      before dialing" and choose "Don't prompt to use Dial-Up Networking".

      (2) Use the Windows REGEDIT program to change value "00 00 00 00" to
      the value "00 00 00 01" in the Windows Registry for the entry
      HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Internet
      Settings/EnableAutodial.

      (3) Use the Windows REGEDIT program to change value "00 00 00 00" to
      the value "00 00 00 01" in the Windows Registry for the entry
      HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Internet
      Settings/EnableAutodisconnect.

      (4) Use the Windows REGEDIT program to change value "14 00 00 00" to
      the value "01 00 00 00" in the Windows Registry for the entry
      HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Internet
      Settings/DisconnectIdleTime. This changes the idle time (until
      disconnect) from 20 minutes (hex 14) to one minute.

      4.3 Key Codes

      When you register FCE, you will receive a new set of DLL's and a key
      code for your DLL's. Pass this keycode as the second argument to
      fceAttach. The keycode will be found in the file KEYCODE.BAS. The
      keycode for the shareware version is 0.





     FCE4VB Users Manual                                       Page 9

      5.0 Theory Of Operation

      The FTP Client Engine is state driven. This means that each call to
      FCE functions (that access the server) is broken down into sequential
      steps, each of which can be performed within a second or two.

      There are two ways in which FCE is used: (1) indirect use of the
      state engine, and (2) direct use of the state engine.

      5.1 Indirect Method

      The first (or "indirect") way to use the FCE library is to allow all
      FCE function calls to automatically call the FCE driver (fceDriver)
      before returning. This is the default way that FCE operates.

      The major advantage of this approach is that each FCE function
      returns only after it has completely finished. The disadvantage of
      this approach is that some functions may run for a considerable
      amount of time during which time the calling application must wait.

      Refer to the sample program WINFTP for an example of this approach.

      5.2 Direct Method

      The second (or "direct") way that the FCE state driver is used is to
      call it (fceDriver) directly. In order to operate this way, the
      function fceSetInteger must be called which sets the AUTO_CALL flag
      to off:

         Code = fceSetInteger(Chan, FCE_AUTO_CALL_DRIVER, 0)

      After the above statement is executed, the state driver (fceDriver)
      must be called after all other FCE functions that access the server.
      For example,

         Code = fceConnect(...)
         If Code < 0 Then
          ' handle error here
         End if
         DO
           ' call the driver
            Code = fceDriver
            If Code < 0 Then
              ' handle error here
            End If
            If Code = 0 Then
              Exit Do
            End If
            ' ... do something here ...
         LOOP

      The major advantage of the direct approach is that the calling
      application can perform other work such as reporting the progress of
      large downloads. The disadvantage is the extra code that must be
      written to call fceDriver.



     FCE4VB Users Manual                                       Page 10

      6.0 Versions of FCE

      The FTP Client Engine (FCE) library is available in three versions.
      All three versions have identical functionality.

      6.1 Shareware Version

      The shareware version can be differentiated from the other two
      versions by:

      (1) The shareware reminder screen is displayed at startup.

      (2) The DLL is branded with "SHAREWARE VERSION".

      The Shareware version may NOT be used for commercial purposes.

      6.2 Student Version

      The student version can be differentiated from the other two versions
      by:

      (1) There is no shareware reminder screen.

      (2) The DLL is branded with "STUDENT VERSION".

      The Student version may NOT be used for commercial purposes. Refer to
      Section 10.3, Student Version.

      6.3 Professional Version

      The professional version can be differentiated from the other two
      versions by:

      (1) There is no shareware reminder screen.

      (2) The DLL is branded with your company name.

      The professional version may be distributed with your application as
      specified by the software license.



















     FCE4VB Users Manual                                       Page 11

      7.0 Using FCE with Other Languages

      The FTP Client Engine DLLs can be used with any application written
      in any language capable of calling the Windows 16-bit or 32-bit API.

      FCE4VB can also be used in VBA applications such as WORD, EXCEL and
      ACCESS. Note that WORD97, ACCESS 97, and EXCEL 97 are 32-bit
      applications. Refer to VBA16.TXT, MODULE16.BAS, VBA32.TXT, and
      MODULE32.BAS.

      Also note that there is a C/C++ version (FCE4C).

      Delphi (FCE4D), PowerBASIC (FCE4PB), Visual FoxPro (FCE4FP), and
      Visual dBase (FCE4DB) versions of FCE are in currently development
      (August 1999).

      If you have interfaced FCE to an unusual language, email us the
      declaration file!

      8.0 Problems

      Before attempting to run any of the example programs, you should
      already be able to connect to the Internet.

      If you cannot get your application to run properly, first compile and
      run the example programs. If you call us to report a possible bug in
      the library, the first thing we will ask is if the example programs
      run correctly.

      Be sure to test the code returned from FCE functions. Then, call
      fceErrorText to get the text associated with the error code.

      For example:

         Dim Buffer As String * 65
         Code = fceConnect(0,"ftp.isp.net","ftp","<[e-mail]>")
         If Code < 0 Then
           Code = fceErrorText(Code,Buffer,64)
           Print "Error " & Str$(Code) & Left$(Buffer, Code)
         End If

      If you encounter a problem that you cannot resolve, give us a call or
      email us at [e-mail].















     FCE4VB Users Manual                                       Page 12

      9.0 Example Programs