It is usually not a good idea to just try to convert code from one language to another line by line.
Sometimes it works, but sometimes not.
Instead try to analyze the code you want to translate and understand what it is supposed to do and then find out how to do it in another language.
In your case it looks like you want to
1. Open a specific COM port.
2. Set communication parameters
3. Write data
4. Read data
But more than this I cannot know, because you don't give that information.
So you need to do this analyse.
For example what kind of communication do you want to do?
* Is it a master - slave setup where one side is always sending data and the other side only respond?
* Who is the master? The PC or the device?
* Will the connected device send data at any time, like a barcode reader?
What do you in general need to do in C# to communicate over a serial port?
1. Set up the communication parameters
string portName = "COM1";
int baudRate = 9600;
Parity parity = Parity.None;
int dataBits = 8;
2. Create an instance of the class SerialPort
SerialPort serial = new SerialPort(portName, baudRate, parity, dataBits);
serial.Encoding = Encoding.GetEncoding("iso-8859-1");
3. Open the port
serial.Open();
4. Write data
serial.WriteLine("Hello World");
or
serial.Write(new byte[] {0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x57, 0x6F, 0x72, 0x6C, 0x64});
5. Read data
string retVal = serial.ReadLine();
or
byte[] buffer = new byte[serial.BytesToRead()];
int bytesRead = serial.Read(buffer, 0, buffer.Length);
You can also use the
SerialPort.DataReceived Event (System.IO.Ports)[
^] for reading bytes. This is useful for, for example, a barcode reader where data can be sent from the reader at any time.
That is the basics of serial communication.
Use MSDN and read the documentation:
SerialPort Class (System.IO.Ports)[
^]
As you don't explain what your goal is, it is difficult to give more help than this.