_Asynchronous Communication and Visual FoxPro_
by Bob Howard


Listing One
001 *!*        Sendit.PRG  *!*
002
003  SET PROC TO sendit.prg
004
005 *!*        Function to Dial the Connection
006
007 DECLARE INTEGER RasDial ;
008        IN C:\WINDOWS\SYSTEM\RASAPI32.DLL ;
009        INTEGER @, INTEGER @, STRING @, INTEGER , INTEGER , INTEGER @
010 
011 *!*        Function to return any errors from the connection
012
013 DECLARE INTEGER RasGetErrorString ;
014        IN C:\WINDOWS\SYSTEM\RASAPI32.DLL ;
015        INTEGER , STRING @ , INTEGER
016 
017 *!*        Function to hang up the phone
018
019 DECLARE INTEGER RasHangUp ;
020        IN C:\WINDOWS\SYSTEM\RASAPI32.DLL ;
021        INTEGER
022 
023 *!* Map a hard drive (volume name) to a drive letter
024 
025 DECLARE INTEGER WNetAddConnection IN Win32API ;
026        STRING @ , STRING @ , STRING @
027 
028 *!* Un-map a local drive letter from a remote drive.
029 
030 DECLARE INTEGER WNetCancelConnection IN Win32API ;
031        STRING @ , INTEGER
032 
033 Zero_value = 0
034 Connection_Handle = 0 && Connection Handle that RASAPI32.DLL gives back
035                       && We will use this to hang up the phone.
036 
037 Double_word_size = CHR(28)+CHR(4)+CHR(0)+CHR(0) 
038                              && Value of 1052 represented as a string
039 Connection_Name = PADR('My Office'+CHR(0),257)
040 Connection_Number = PADR('555-1212'+CHR(0),129)
041 Callback_Number = PADR(''+CHR(0),129)
042 User_Name = PADR('RDH'+CHR(0),257)
043 Connection_Password = PADR('MyPassword'+CHR(0),257)
044 Domain_name = PADR(''+CHR(0),16)
045 
046 String_to_pass = Double_word_size + ;
047        Connection_Name + ;
048        Connection_Number + ;
049        Callback_Number + ;
050        User_Name + ;
051        Connection_Password + ;
052        Domain_name
053 
054 String_to_pass = PADR(String_to_pass,LEN(String_to_pass)+
055                                      (4 - LEN(String_to_pass) % 4))
056 WAIT 'Dialing ' + SUBSTR(Connection_Name,1,50) WINDOW NOWAIT
057 
058 Return_Value=RasDial(Zero_value,Zero_value,@String_to_pass,Zero_value, ;
059        Zero_value, @Connection_Handle)
060           
061 IF !EMPTY(Return_Value)                 
062     Message_Buffer = SPACE(256)     && Placeholder for error message
063     IF !EMPTY(RasGetErrorString(Return_Value,@Message_Buffer,
064                                          LEN(Message_Buffer)))
065           WAIT 'Unknown error' WINDOW
066     ELSE          
067           WAIT ALLTRIM(Message_Buffer) WINDOW
068     ENDIF
069 ENDIF
070 Drive_letter = 'W:'
071 Volume_name = '\\My Office\C'
072 Drive_Password  = ''
073 
074 IF !EMPTY(WNetAddConnection(@Volume_name, @Drive_Password, @Drive_letter))
075        WAIT 'Drive not mapped' WINDOW
076 ELSE
077        WAIT 'Drive mapped.... ' + ALLTRIM(Volume_name) + ' to ' + ;
078 Drive_letter WINDOW 078 TIMEOUT 3
079 ENDIF
080 
081 *------------------------------------------------------------------------
082 
083 COPY FILE C:\autoexec.bat TO W:\Temp\Autoexec.bat
084  
085 IF FILE('\\My Office\C\Temp\Autoexec.bat')
086        WAIT 'Copied Successfully' WINDOW TIMEOUT 5
087 ELSE
088        WAIT 'Not Copied' WINDOW
089 ENDIF
090 
091 *!*         Un-map a local drive letter from a remote drive
092 
093 Drive_letter = 'W:'
094 
095 IF !EMPTY(WNetCancelConnection(Drive_letter, .T.))
096        WAIT 'Un-mapping Failed' WINDOW NOWAIT
097 ELSE
098        WAIT 'Un-mapped ' + Drive_letter + '.' WINDOW NOWAIT
099 ENDIF
100 
101 Return_Value = RasHangUp(Connection_Handle)     && hangup the connection
102 
103 WAIT '' TIMEOUT .5
104 WAIT 'Process Complete.' WINDOW
106
107 Function Convert_to_Double_Word
108
109 Double_word_size = ''
110 Number_to_convert = 1052
111  FOR i = 1 TO 4
112    Double_word_size = Double_word_size + CHR(Number_to_convert % 256)
113    Number_to_convert = INT(Number_to_convert / 256)
114  NEXT
115  RETURN Double_word_size