Question

I’m trying to make Login feature by using TCP Client. I have two forms: Client-side and Server-side.

The Client-side handles user input while Server-side connect to database.

The problem is the reader result, which always combine both inputs into one long string like this:

   myusernamemypassword

Here’s part of the sender of client-side:

    byte[] byteUsername = Encoding.Unicode.GetBytes(username);
    byte[] bytePassword = Encoding.Unicode.GetBytes(password);

    NetworkStream stream = client.GetStream();

    stream.Write(username, 0, byteUsername.Length);
    stream.Write(password, 0, bytePassword.Length); 
        //if offset != 0, the code always return ArgumentOutOfRangeException

And the reader in server-side:

    return Encoding.Unicode.GetString(buffer, 0, buffer.Length)

After long-search I found the solution, but it can only handle two strings; the third+ string will be combined together with the second string. I need to send at least 4 strings for other feature.

Here’s the updated reader code:

List<string> list = new List<string>();
int totalRead = 0;
do
{
    int read = client.GetStream().Read(buffer, totalRead, buffer.Length - totalRead);

    totalRead += read;

    list.Add(Encoding.Unicode.GetString(buffer, 0, totalRead));

} while (client.GetStream().DataAvailable);

I don’t quite understand this code. How can it knows which bytes are part of the first string? The size of Read() parameter is length-totalRead which is length - 0, it should return the whole buffer right?

Any solution guys?

Thanks before

Answer 1

You should prefix each string with its length (in bytes, not characters) as a 4-byte integer.
This way, the server will know how many bytes to read into each string.