C# socket Receive Problem of socket receiving data

Question

When I try to accept website images.I use Socket.Receive().However, the data size it accepts does not match the actual data size.Moreover, the size of the received data changes every time.I tried to add "thread. Sleep (500)" before "socket. Receive", and it will be normal.So I think it may be that the program did not wait for the data transfer to complete when reading the data.So I tried the method of receiving data in a loop, but I can't know under what circumstances the data can be received completely.Oh.How can I solve this problem.thanks!!!!

Answer 1

Hello,
I see that the example for using Socket.Receive at the below msdn link, example code is at the end of this reply:
https://learn.microsoft.com/en-us/dotnet/api/system.net.sockets.socket.receive?view=net-6.0

Have you tried in the same way and is it not working even after using code as below given example? Please let me know if it does not work for you.

// Receive the host home page content and loop until all the data is received.
Int32 bytes = s.Receive(RecvBytes, RecvBytes.Length, 0);
strRetPage = "Default HTML page on " + server + ":\r\n";
strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);

while (bytes > 0)
{
bytes = s.Receive(RecvBytes, RecvBytes.Length, 0);
strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);
}

Answer 2

Http images are read via http 1.1 protocol. There are headers, one that give the body length. See

https://developer.mozilla.org/en-US/docs/Web/HTTP/Overview

As keep alive is usually set, so the next request will not require a new connection, the data length is important. If no length is sent, than a fin is used.

Note: you must read and parse the headers, before you know the length. The headers will also tell you of and compression used.