Read/Write Values at a Given Hex Address Offset

[Dave]

Greetings,

How do I read the hex value of a binary file at a given offset? i.e., how
can I find out, via code, what the 2-digit hex code is at, say, offset
132ea. Then, how would I write over that value?

Thanks,

-Dave

 

[Mattias Sjögren]

How do I read the hex value of a binary file at a given offset? i.e., how
can I find out, via code, what the 2-digit hex code is at, say, offset
132ea. Then, how would I write over that value?

Open a FileStream, Seek() to offset &H132ea and then read/write from
there (using for example a BinaryReader/BinaryWriter).



Mattias

 

[Dave]

Thanks for your help, I'll try it out.

Open a FileStream, Seek() to offset &H132ea and then read/write from
there (using for example a BinaryReader/BinaryWriter).



Mattias

 

[james]

Dim MyAddress as Short = &H132
' assumes that you are using the OpenFileDialog to get the path & Filename
Dim filename As String = OpenFileDialog1.FileName

Dim fs As FileStream = New FileStream(filename, FileMode.Open)

Dim br As BinaryReader = New BinaryReader(fs)

Dim sz As Integer = fs.Length' you don't neccessarily need this, I use this in my app. toset the size an Array.



br.BaseStream.Seek(MyAddress, SeekOrigin.Begin)'moves to the address you want

a = br.ReadInt32() 'reads Both Bytes (characters you want)

ListBox1.Items.Add("My Address Data: " + (a).ToString()) 'Adds the data to a listbox

br.Close()'close the Binary Reader

fs.Close()' close the FileStream



To overwrite the character(s) just do the reverse and use the Binary Writer. (make sure you don't write more than the number of
characters (Bytes) you need to or you will overwrite (corrupt) data you don't intend to.

james

 

[james]

Forgot one little thing

Dim a as Object

I always forget something!!
(over th hill and gaining speed)
james