如何在c#中从串口读取字节数组

我有一个c#串口编程的问题
我的目标是将ByteArray发送到串行端口，然后获得ByteArray。但是我无法从串口获取。我试着:

string gelen = port.ReadExisting();
   int asd = port.ReadByte();
   string qwe = port.ReadLine();

谁能告诉我出了什么事?由于我代码:

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.IO.Ports;
    namespace serial_port_app
    {
        public partial class Form1 : Form
        {
            public Form1()
            {       
                InitializeComponent();
            }
            private void button1_Click(object sender, EventArgs e)
            {
                int text1, text2,text3,text4,text5, text6;
                Int32.TryParse(textBox1.Text, out text1);
                byte byteValue1 = Convert.ToByte(text1);
                Int32.TryParse(textBox2.Text, out text2);
                byte byteValue2 = Convert.ToByte(text2);
                Int32.TryParse(textBox3.Text, out text3);
                byte byteValue3 = Convert.ToByte(text3);
                Int32.TryParse(textBox4.Text, out text4);
                byte byteValue4 = Convert.ToByte(text4);
                Int32.TryParse(textBox5.Text, out text5);
                byte byteValue5 = Convert.ToByte(text5);
                Int32.TryParse(textBox6.Text, out text6);
                byte byteValue6 = Convert.ToByte(text6);

                byte[] byteArray = new byte[6];
                byteArray[0]=byteValue1;
                byteArray[1]=byteValue2;
                byteArray[2]=byteValue3;
                byteArray[3]=byteValue4;
                byteArray[4]=byteValue5;
                byteArray[5]=byteValue6;

                SerialPort port = new SerialPort("COM1", 9600, Parity.None, 8,      StopBits.One);
                port.Open();
                port.Write(byteArray,0,6);
>>>>>>>>>>>>>   string text = port.ReadExisting();
>>>>>>>>>>>>>   int asd = port.ReadByte();
>>>>>>>>>>>>>   string qwe = port.ReadLine();
                int n=dataGridView1.Rows.Add();
                    dataGridView1.Rows[n].Cells[1].Value = text;
                    dataGridView1.Rows[n].Cells[2].Value = asd;
                    dataGridView1.Rows[n].Cells[3].Value = qwe;
                    dataGridView1.Rows[n].Cells[4].Value = text4;
                    dataGridView1.Rows[n].Cells[5].Value = text5;
                    dataGridView1.Rows[n].Cells[6].Value = text6;

                    if ((n % 2) == 0)
                        dataGridView1.Rows[n].DefaultCellStyle.BackColor = Color.LightBlue;
                    else
                        dataGridView1.Rows[n].DefaultCellStyle.BackColor = Color.LightGreen;
                    port.Close();
            }

编辑正确答案:

删除:

string text = port.ReadExisting();
int asd = port.ReadByte();
string qwe = port.ReadLine();

并添加:

port.DtrEnable = true;
 port.RtsEnable = true;
 int bytes = port.BytesToRead;
 byte[] buffer = new byte[bytes];
 port.Read(buffer, 0, bytes);