This should be simple! Read a File into a Byte Array

[Shaun Merrill]

Hey, here is my code. I am trying to read a file into a byte array. Please
show me how this can work.
Obviously I need to read into a dynamic array because it could read any
file. So why does VB.NET give me the ability to read into a Byte Array if
it doesn't allow me to use a variable sized array?

Dim i As Short = FreeFile()
FileSystem.File Open(i, Filename, OpenMode.Binary , OpenAccess.Read ,
OpenShare.Defau lt)
Dim iByteArray() As Byte
ReDim iByteArray(LOF( i))
FileSystem.File Get(i, iByteArray, True)
FileSystem.File Close(i)

This code bombs on FileGet(), throwing an EndOfStream exception "Unable to
read beyond the end of the stream."
Even if I use no Redim statement, I get "Cannot determine array type because
it is Nothing."

Obviously, the ArrayIsDynamic parameter is set to True. What am I doing
wrong?!?

~ Frustrated

[Lucas Tam]

"Shaun Merrill" <[e-mail]> wrote in
news:OW******** ******@TK2MSFTN GP12.phx.gbl:

Hey, here is my code. I am trying to read a file into a byte array.
Please show me how this can work.
Obviously I need to read into a dynamic array because it could read
any file. So why does VB.NET give me the ability to read into a Byte
Array if it doesn't allow me to use a variable sized array?

Dim i As Short = FreeFile()
FileSystem.File Open(i, Filename, OpenMode.Binary , OpenAccess.Read ,
OpenShare.Defau lt)
Dim iByteArray() As Byte
ReDim iByteArray(LOF( i))
FileSystem.File Get(i, iByteArray, True)
FileSystem.File Close(i)

This code bombs on FileGet(), throwing an EndOfStream exception
"Unable to read beyond the end of the stream."
Even if I use no Redim statement, I get "Cannot determine array type
because it is Nothing."

Obviously, the ArrayIsDynamic parameter is set to True. What am I
doing wrong?!?

I think you need to set the preserve keyword:

Redim preserve ibyteArray(LOF( i))

Also, you should be dimming LOF(i) - 1, because arrays are 0-based (so a
byte array of 19999 is really 20000 bytes)

--
Lucas Tam (RE********@rog ers.com)
Please delete "REMOVE" from the e-mail address when replying.
http://members.ebay.com/aboutme/coolspot18/

[Cor Ligthert]

Shaun,

This should be enough

\\\
Dim fs As New IO.FileStream(F ilePath, _
IO.FileMode.Ope n)
Dim br As New IO.BinaryReader (fs)
abyt = br.ReadBytes(CI nt(fs.Length))
br.Close()
///

I hope this helps?

Cor

"Shaun Merrill" <[e-mail]>

Hey, here is my code. I am trying to read a file into a byte array.
Please show me how this can work.
Obviously I need to read into a dynamic array because it could read any
file. So why does VB.NET give me the ability to read into a Byte Array if
it doesn't allow me to use a variable sized array?

Dim i As Short = FreeFile()
FileSystem.File Open(i, Filename, OpenMode.Binary , OpenAccess.Read ,
OpenShare.Defau lt)
Dim iByteArray() As Byte
ReDim iByteArray(LOF( i))
FileSystem.File Get(i, iByteArray, True)
FileSystem.File Close(i)

This code bombs on FileGet(), throwing an EndOfStream exception "Unable to
read beyond the end of the stream."
Even if I use no Redim statement, I get "Cannot determine array type
because it is Nothing."

Obviously, the ArrayIsDynamic parameter is set to True. What am I doing
wrong?!?

~ Frustrated

[Herfried K. Wagner [MVP]]

"Cor Ligthert" <no************ @planet.nl> schrieb:

Dim fs As New IO.FileStream(F ilePath, _
IO.FileMode.Ope n)
Dim br As New IO.BinaryReader (fs)
abyt = br.ReadBytes(CI nt(fs.Length))

.... for files with length <= 'Int32.MaxValue '.

;-)

--
Herfried K. Wagner [MVP]
<URL:http://dotnet.mvps.org/>