Vb6 Read Binary File Into Byte Array

Jun 24, 2008 Read and Write Binary Files in VB6, VBScript, ASP. The Chilkat FileAccess ActiveX is a freeware component that may be used to read and write binary files in VBScript, ASP, VB6, etc. Here are some sample code fragments: VBScript. C# reading binary file or byte array to EOFHere is my problem: Some binary files have. From my understanding it used to increase the memory space for the program should it later need use of it but it causes a problem for me, if I read a binary file into an array then execute it directly into memory it causes the process to crash since the extra bytes create a problem.

Doing cryptographic operations in Classic Visual Basic 6 and VBA is tricky because VB6 doesn'thave unsigned types (except the Byte type).That da*n sign bit keeps messing things up. A simple operation in C likex<<=8 is not a simple matter with a Long variable in VB6.Try this experiment:

This will 'carry over' the sign bit into the high word and print:Which is not what we expect. The correct way is to append an ampersand (&) to cast it as a proper long:Likewise, migrating values from string types to bytes and words has itsdifficulties.To convert back-and-forth between

Binary File Virus

String typesand Byte arrays, use the built-in VBAStrConv() function.This should produce the results:

Note how the StrConvfunction avoids the need to declare the size of the byte array beforehand.(Thanks to Robert Garofalo for pointing out this useful function).For more information see Using StrConv with ANSI, DBCS and Unicode charactersets.

If you want to convert to a byte array without the Unicode conversion,do this:

This will produce the result:This time, we get two bytes for each Unicode character.See Microsoft Knowledge Base Article - 187675 HOWTO: Copy a String to a Byte Array Without Unicode Conversion

for more details.

If you want the string encoded in UTF-8, seeHow to convert VBA/VB6 Unicode strings to UTF-8.

VB6/VBA Code

The functions provided here inbasConvert andbasUnsignedWordcan help you manage some of these issues in your code.Thanks to Ernie Gibbs for pointing out a subtle error in basUnsignedWord.uw_WordAdd (2008-06-25).The code in basConvert replaces the now supersededbasByteUtilswith better and faster dynamic arrays.However, the functions in basByteUtils are still useful for ASP and VBScript applications.The source code to these three files is in binaryutils.vb6.zip (9 kB).

Note: Users with operating systems that are set up to use full 32-bit Unicode OS or oriental CJK charactersmay need to do a global replace of Asc() and Chr() with AscW() and ChrW() in the basConvertand basByteUtils functions above. Thanksto David Wolf of Intuit Information Technology Solutions for this tip.

For more hints on how to use arrays of the Byte type in Visual Basic 6 compared to thesimpler String type, see Using Byte Arrays in VB6/VBA.

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Vb6 Read Binary File Into Byte Array

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