[RESOLVED] Receiving Bytes Problem(How to Receive??)

the current module i am doing, receives some data bytes from winsock(for testing purpose temporarily in com port). from my previous experience, i would collect the data bytes received from port, write it to a file and read the file to get the appropriate fields.

the reason why i write to file is., the data packet which i receive will be like this ., for ex.,

id int,
deviceid int,
customername char[17],
amount float.
and i receive it as packet(collection of all these). i write the packet to the file and open the file and i will store it in the type which is in the exact format in which the packet has been sent. like this.,

Type info
ID as Integer,
DeviceID as Integer,
Cust_Name as String * 17,
Amount as Double
end Type

and use this as .,

dim Config as info
Open SavedFile For Binary Access Read As #fileno
Get #fileno, 1, Config
'SavedFile(variable) has the name of the file in which i stored the bytes.


now i get the values in the file in the variable Config. I get the data like this. I wanted to know is there any way around to skip the file process.

"In Short, I wanted to read the bytes received from port(either from winsock or com) and store it in VB's variables for my process"

It looks like one end point of the connection is written in C. I have done quite a few VB-to-C sockets apps. Here is how I do it.

Like you, I create a UDT that matches my C struct. I use the CopyMemory API to copy the UDT to a byte array before sending it. In the Data_Arrival code, I read the data into a byte array and use CopyMemory to copy the data to the UDT.

Are the client and server both running on Windows platforms? If not, you may have issues with big-endian vs little-endian and with your floats/doubles. There are APIs to deal with the endian issues. As for the floats/doubles, I have never had a need use them, but most people that I have talked to have said that the easiest way to pass them between different platforms (where they may be stored differently) is to convert them to/from strings and pass the strings.

Email me if you would like an example app that demonstrates all of the above (except the floats).

hi,

i would certainly like to have the sample. and i receive data from a device. so it is embedded C. (Note : the data contains definite number of bytes for each fields)

I would also like to know, how the data is passed generally in winsock, or com from devices., if it is not string.

hi CCoder,
"CopyMemory" was a very good/useful solution. Thanks a lot. and sorry for very late acknowledgement.