Overflow problem with winsock in vb6

I have built a simple project which use "Winsock" Tool.

When I receive any data I put it in a variable because i cann't put it in a textbox because it is a file not a text.

But if i send a big file it gets me an error.

"Overflow"

Are there any way to fix this problem ?

A VB variable-length string can only in theory be 2GB in size, it's actual maximum size is depending on available virtual memory which is also limited to 2GB for the entire application. But since VB stores the string in unicode format it means that it can only contain 1GB of text.

(maximum length for string in VB6)

If this is your problem, try splitting incoming data by several strings.

Are you handling the SendComplete event properly before sending more data?

Otherwise you will get a buffer overflow from the WinSock control.

You need to split your data into smaller packets (around 2-5k each should do it) and send each packet individually, then re-construct your packets at the other end. You could add a unique character at the end of the data so that the receiving end know that all the data has been received for that transmission say Chr(0)?

This is quite a simplified solution to this problem - a better method would be to devise a simple protocol for data handshaking so you know each packet has been received.