窗口间控件的相互操作

[weixin_38053088]

（窗口2有一个串口控件）“”控制按钮“”第一次按下，打开窗口2，在发送区写入相关内容，第二次按下按钮，就发送去的内容（通过串口）送到第一个窗口的接收区。自己写的没有错误提示，但是运行也不成功。
form1-----------------------------------------------
using oprate_serialport;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace oprate_serialport
{

public partial class Form1 : Form
{
public delegate void newdeleeventhandle(object sender, EventArgs e);
public event newdeleeventhandle newevent;

public Form1()
{
InitializeComponent();
// newevent += newform2.uartset;
// newevent += newform2.onuart;
}

public void onnewevent(object sender, EventArgs e)
{
if (newevent != null) newevent(this, e);
}

int num = 0;
private void sport_oprate_Click(object sender, EventArgs e)
{
Form2 newform2 = new Form2();

num++;
if (num == 1)
{
newform2.Show();
}
else
{
if (num==2)
{
newform2.onuart (0,null);//不传输内容
num = 1;
}

}

}
}
}form2---------------------------------------using System;using System.Windows.Forms;using System.IO.Ports;namespace oprate_serialport{    public partial class Form2 : Form    {        public Form2()        {            InitializeComponent();                     }        private void Form2_Load(object sender, EventArgs e)        {            first_port.PortName = "COM1";            first_port.BaudRate = 9600;            first_port.DataBits = 8;            first_port.StopBits = StopBits.One;            first_port.Parity = Parity.None;        }        public void onuart(object sender, EventArgs e )        {            Form1 newform1 = new Form1();              first_port.Open();            first_port.WriteLine(senddata.Text);            string  data2 =(first_port.ReadLine( ));            newform1.receivedata.Text =(data2);            first_port.Close();        }           }}