How to pass a Hex String to a TCP connection and Read the Result

问题

I have the following script (thanks to @SavindraSingh for the link).

I am trying to pass the $message below to the $remotehost $port and capture the response.

$port=12345
$remoteHost = "1.2.3.4"
$message="\x40\x00\x23\x01\x00\x00\x00\x40"

$socket = new-object System.Net.Sockets.TcpClient($remoteHost, $port)

$data = [System.Text.Encoding]::ASCII.GetBytes($message)

$stream = $socket.GetStream()
$stream.Write($data, 0, $data.Length)

The problem is that the ASCII.GetBytes converts each character to it's individual 'bytes' (as expected). However, if I simply do $data=$message I get the following error:

Cannot convert argument "0", with value: "\x40\x00\x23\x01\x00\x00\x00\x40", for "Write" to type "System.Byte[]"
: "Cannot convert value "\x40\x00\x23\x01\x00\x00\x00\x40" to type "System.Byte[]". Error: "Cannot convert value
"\x40\x00\x23\x01\x00\x00\x00\" to type "System.Byte". Error: "Input string was not in a correct format."""
At line:13 char:14
+ $stream.Write <<<< ($data, 0, $data.Length)
+ CategoryInfo          : NotSpecified: (:) [], MethodException
+ FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument

How can I pass across my $message (a string of hex values).

And how would I see the response (write-host $stream just says System.Net.Sockets.NetworkStream).

--- UPDATE 2016-07-14 ---

Based on the documentation, and pieces I've gleaned elsewhere, I've added the following to try and Read the response:

$reader = New-Object System.IO.StreamReader($stream)

$buffer = new-object System.Byte[] 1024
$encoding = new-object System.Text.AsciiEncoding

$rawresponse = ""

$response1 = $reader.Read($buffer, 0, 1024)
$response2 = $encoding.GetString($buffer, 0, $rawresponse)

write-host $response1
write-host $response2

But from this $response1 always returns 0, 20 , or 21 And $response2 returns nothing. I was expecting a text string similar to #@3e1###f9 which is what my application should be returning.

Have I misunderstood something somewhere?

来源：https://stackoverflow.com/questions/38353658/how-to-pass-a-hex-string-to-a-tcp-connection-and-read-the-result