Insert value in array of bytes

First, please use a message title which reflects the actual question you are asking. When people are looking through the list for questions that they may be able to answer, or would also like to know about, "Help Me On This" is not going to attract any attention. You are just shooting yourself in the foot, and making the forum less useful for the rest of us.

Anyway...

Here's a function I've just written (have not tested it, so use it at your own risk) to insert a new byte value into an existing byte array at the specified position. It should be some help in this case...

Thanks Killer42.its Realy Helpful

How i can use the above function to call the insert byte function?Here i just wana insert do wana replace .No idea .Can u explain how i can do this?

It goes at the point in your logic where you have decided you want to insert something into your array.

By the way, I see you have another post asking how to delete something out of a byte array. I'd suggest you pick apart the insert routine I wrote, and modify it to work as a delete. This should be quite simple, really.

Public Function InsertByte(pmArray() As Byte, pmPosition As Long, ByVal pmNewValue As Byte)
' Function to insert a new byte value into a byte array.
Dim ArrayStart As Long, ArrayEnd As Long
Dim I As Long
ArrayStart = LBound(pmArray)
ArrayEnd = UBound(pmArray) + 1
' Expand array to make room for the new value.
ReDim Preserve pmArray(ArrayStart To ArrayEnd)
' If requested position is outside the array, just stick it
' at the start or end as appropriate.
If pmPosition < ArrayStart Then
pmPosition = ArrayStart
End If
If pmPosition > ArrayEnd Then
pmPosition = ArrayEnd
End If
' Unless adding to the end of the array,
' push everything across to make room.
If pmPosition < ArrayEnd Then
For I = ArrayEnd To pmPosition + 1 Step -1
pmArray(I) = pmArray(I - 1)
Next
End If
pmArray(pmPosition) = pmNewValue
End Function

please explain what this coding doing?i cant undersatand what actualy this coding is doing

Ok, my code had a couple of little bugs, which I've now corrected (I highlighted the corrections in your message).

All it does is take an array of bytes, and insert another one at the requested position.

Here's a sample program which should help to illustrate it. It creates a byte array, places the word "Hello" in it (ASCII values of the letters), then calls that Sub to insert an "A" in the third position. It displays the size and contents of the array, before and after.

To run this, just create a new project, add a module, set the startup object to Sub Main, add a copy of the original InsertByte routine, and paste in this code...
If you want to know what the InsertByte routine does in more detail, just follow it through, statement by statement. But you don't actually need to understand it in order to use it. You can treat it as what's generally referred to as a "black box". It's just a box that takes some input and produces some output - you don't actually need to know what's inside the box.

I can understand now what the function is doing.This function already specify that insertion will happen in the 3rd place.How if we dont no the insertion will be happen at which place.We ourself finding the correct place to do insertion.This function only read until byte 10.How if i wana read until eof and figure out the place to do insertion.Let say for eg
04 FF 79 04 3B 04 04 FF- 7A 04 3B 04 04 FF 7B 04
3B 04 04 FF 7C 04 3B 04- 04 FF 7D 04 3B 04 04 FF
7E 04 3B 04 7F 04 3B 04 - 04 FF 80 04 3B 04 04 FF

Here 04 FF is missing betwen 04 7F and I would like to insert the 04 FF values and i do no how to maniplate the eg coding that you give

Sorry, but I think you need to work out for yourself the logic of what you want to do. Then we can help with the coding. If you can explain in enough detail where you need to insert these bytesm then the code will more or less take care of itself.

The point of that InsertByte routine is to make the process easier. Once you work out where you want to insert a byte, you can just call that routine to do it.

P.S. When posting source code, please use CODE tags as outlined in the Posting Guidelines.

is it correct way.im using the insert function.So am i using it correctly?

I would say you're probably getting quite close to what you want.

But lines 42 and 46 look wrong. I assume they are intended to call the InsertByte routine, in which case the name and parameters are both wrong. The parameters is accepts are as follows:

1. The array into which a byte is to be inserted,
2. The position in the array to insert the new value, and
3. The value to be inserted.

In the case of line 42 for example, that would be:
A couple of other things to consider...

• My apologies. I really should have made InsertByte a Sub, rather than a Function, since it doesn't return anything. Probably doesn't matter much, though.
• If you think about it, each time you call InsertByte, the array will get one byte longer. But your variable mfilesize will still be the same.
  You can add 1 to mfilesize each time, but the For loop will still finish too early.

Hm...

I tell you what. I finally have a little time on my hands, so I'll try a quick rewrite to allow for the expansion of the array. Note, I won't include the InsertByte sub here, as it's just a waste of space. We'll assume you already have it. You should be able to paste this into a new code module in VB, then just copy in the other functions required, like HexByte2Char and InsertByte.

Also, note that I went back through some earlier posts and pulled together info top try and make this the complete "fix an open file" routine. You will probably still need to adjust things a bit. I have not tested this at all.

thanks killer42.Thanks alot for ur guidance

can i call the rewrite function like this


why it giving the error the argument isnot optional

can i call the rewrite function like this

Expand|Select|Wrap|Line Numbers

1.  private command 1( )click 
2.   rewrite_open_file
3. end sub
4.  

why it giving the error the argument isnot optional

The error is quite self-explanatory. The rewrite_open_file routine requires an argument, and you didn't supply one. In this particular case, it expects the number of the currently open file.

Hang on, I'll have a go at rewriting it again so you can just call it. Better still, I'll set it up to accept a filename as an argument. So you can say Rewrite_File "A:\aaa.txt" or whatever.

Give me ten minutes...

Ok, more like 40 minutes. Anyway, here is my little trial project. I have compiled it, but haven't actually tried it out on any files yet.

Be careful, as it could destroy any file you use it on.

killer42 ,the insertion part is success.Thanks alot.U are helping me alot.Thank you very much for ur guidance.Thanks alot sir

killer42 ,the insertion part is success.Thanks alot.U are helping me alot.Thank you very much for ur guidance.Thanks alot sir

Glad to hear it helped. :)

And perhaps more importantly, I hope you've picked up some programming tips that will help you resolve further problems.