将程序中的ascii码改为16进制应该怎么该！求指导

Question

try
{

            // Translate the passed message into ASCII and store it as a Byte array.
            Byte[] data = System.Text.Encoding.ASCII.GetBytes(message);
            // Get a client stream for reading and writing.
            //  Stream stream = client.GetStream();

            NetworkStream stream = client.GetStream();

            // Send the message to the connected TcpServer. 
            stream.Write(data, 0, data.Length);

            Console.WriteLine("Sent: {0}", message);

            // Receive the TcpServer.response.

            // Buffer to store the response bytes.
            data = new Byte[256];

            // String to store the response ASCII representation.
            String responseData = String.Empty;

            // Read the first batch of the TcpServer response bytes.
            Int32 bytes = stream.Read(data, 0, data.Length);
            responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
            return responseData;
            //Console.WriteLine("Received: {0}", responseData);

            // Close everything.
            stream.Close();

        }
        catch (ArgumentNullException e)
        {

Answer 1

public class TestAscii {

public static void main(String[] s){
printAsciiHex('a');
printAsciiHex('1');

printHex(1);
printHex(16);
printHex(18);
printHex(255);
}

public static void printAsciiHex(char ch){
int i=(int)ch; //i=a的ASCII
System.out.println(ch + " ascii:" + i);

String str=Integer.toString(i,16); //十六进制
System.out.println(ch + " ascii 的十六进制:" + str);
}

//得到一个数的十六进制形式
public static void printHex(int i){
String str=Integer.toString(i,16); //十六进制
System.out.println(i + "的十六进制:" + str);
}
}