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GDI+: copying to the Clipboard (a) image of active FoxPro window/form, (b) image file
GDI+: Storing content of the Clipboard to a bitmap file
How to change display settings: screen resolution, screen refresh rate
How to register custom Event Log source
How to play MIDI notes
Capturing keyboard activity of another application with the Raw Input API (VFP9)
Custom GDI+ class
How to display Windows On-Screen Keyboard
Enumerating raw input devices attached to the system (keyboard, mouse, human interface device)
Copying picture of the active form to the Clipboard using Enhanced Metafile API functions
How to play AVI file on the _screen
How to prevent users from accessing the Windows Desktop and from switching to other applications
How to convert a bitmap file to monochrome format (1 bpp)
Winsock: sending email messages (SMTP, port 25)
Custom HttpRequest class (WinINet)
Custom HttpRequest class (WinHTTP)
Storing content of the Clipboard to a bitmap file
Using Video Capture: displaying on FoxPro form frames and previewing video obtained from a digital camera
How to copy the image of a form to the Clipboard using Bitmap API functions
Mapping and disconnecting network drives
Using FoxTray ActiveX control: System Tray Icon and menu attached to VFP form
HOWTO: Use the Win32 API to Access File Dates and Times
Using WM_COPYDATA for interprocess communication (VFP9)
Retrieving the name of the primary domain controller (PDC) and join status information
How to perform Base64 encoding/decoding using Cryptography API Functions

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#DEFINE CRYPT_STRING_BASE64 0x0001
#DEFINE CRYPT_STRING_NOCRLF 0x40000000
#DEFINE CRYPT_STRING_NOCR 0x80000000

DO declare

LOCAL cBuffer, cEncoded, cDecoded

TEXT TO cBuffer NOSHOW
Base cryptographic functions provide the most flexible means 
of developing cryptography applications. All communication 
with a cryptographic service provider (CSP) occurs through 
these functions.

A CSP is an independent module that performs all cryptographic 
operations. At least one CSP is required with each application 
that uses cryptographic functions. A single application can 
occasionally use more than one CSP.
ENDTEXT

cEncoded = ToBase64(m.cBuffer)
? cEncoded

cDecoded = FromBase64(cEncoded)
? cDecoded

* end of main

FUNCTION ToBase64(cSrc)
    LOCAL nFlags, nBufsize, cDst
    nFlags=CRYPT_STRING_BASE64

    nBufsize=0
    = CryptBinaryToString(@cSrc, LEN(cSrc),;
        m.nFlags, NULL, @nBufsize)

    cDst = REPLICATE(CHR(0), m.nBufsize)
    IF CryptBinaryToString(@cSrc, LEN(cSrc), m.nFlags,;
        @cDst, @nBufsize) = 0
        RETURN ""
    ENDIF
RETURN cDst

FUNCTION FromBase64(cSrc)
    LOCAL nFlags, nBufsize, cDst
    nFlags=CRYPT_STRING_BASE64

    nBufsize=0
    = CryptStringToBinary(@cSrc, LEN(m.cSrc),;
        nFlags, NULL, @nBufsize, 0,0)

    cDst = REPLICATE(CHR(0), m.nBufsize)
    IF CryptStringToBinary(@cSrc, LEN(m.cSrc),;
        nFlags, @cDst, @nBufsize, 0,0) = 0
        RETURN ""
    ENDIF
RETURN m.cDst

PROCEDURE declare
    DECLARE INTEGER CryptBinaryToString IN Crypt32;
        STRING @pbBinary, LONG cbBinary, LONG dwFlags,;
        STRING @pszString, LONG @pcchString

    DECLARE INTEGER CryptStringToBinary IN crypt32;
        STRING @pszString, LONG cchString, LONG dwFlags,;
        STRING @pbBinary, LONG @pcbBinary,;
        LONG pdwSkip, LONG pdwFlags

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1750 bytes  
Created: 2001-08-03 12:00:00  
Modified: 2010-04-08 11:20:04  
Visits in 7 days: 48  
Listed functions:
CryptBinaryToString
CryptStringToBinary
Printer friendly API declarations
My comment:
In VFP8 base64 conversion is normally performed with STRCONV().

In my tests, API routines presented on this page encoded and decoded strings approximately 2 times faster than STRCONV() did -- on 100K cycles 3.7 seconds vs. 7.7 seconds.

This is an output from call to CryptBinaryToString with dwFlags set to CRYPT_STRING_HEXASCIIADDR (0x000b). Can make a good starting point for programming a simple binary viewer.


* * *
From Burkhard Stiller`s VFP Blog:
Another way to encode and store picture-data inside your classes -- relates to base64 encoding, and is an interesting piece of code by itself.
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