将文本框数据转换为字节，然后发送到串行端口，反之亦然

Question

I am very new to C# and using VS, but need a little help.

I have a textbox where a user can put in a value, for example "658" . I want to convert this into bytes first (max 3 bytes) before sending it to the serialport. So the first byte sent is 0x02 and the second byte sent is 0x92 .

The second thing I am having issues with is the same but in reverse. I receive data in bytes, for example "0x0B, 0xC7, 0x14" and then I need to convert them into a decimal value and display them in a different Textbox.

I have tried a number of conversions that did not seem to work (parse, Tobyte and even using binary converter) so I am in need of help.

Thanks

Answer 1

This should get you started:

Convert From Numeric to Bytes:

var textInput = "658";
// validate...
var numericInput = Convert.ToInt32(textInput);
var convertedToBytes = BitConverter.GetBytes(numericInput);
// if your system is little endian (see below), reverse array output.

Convert From Bytes to Numeric:

// fourth octet is required to convert to an int32, which requires 4 bytes.
var bytesInput = new byte[] { 0x0, 0x0B, 0xC7, 0x14 }; 
// if your system is little endian (see below), reverse array.
var convertedFromBytes = BitConverter.ToInt32(bytesInput, 0);

Note, you want to pay attention to endian-ness. See this: https://msdn.microsoft.com/en-us/library/bb384066.aspx

Answer 2

You can use Encoding.GetBytes and Encoding.GetString to convert string to byte[] and back.

https://msdn.microsoft.com/ru-ru/library/ds4kkd55(v=vs.110).aspx

https://msdn.microsoft.com/ru-ru/library/744y86tc(v=vs.110).aspx

Answer 3

That should no be a problem as both the sending and the receiving serial port will accept/return a byte array. So the question comes down to how you create a by array from a string.

byte[] bytes = Encoding.ASCII.GetBytes(textBox1.Text);

The way back is:

string s = Encoding.ASCII.GetString(bytes);