用事件进行窗口间参数传递

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;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
        }
        private Form2 m_dlg;

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 dlg = new Form2(richTextBox1.Text);
            if (dlg.ShowDialog() == DialogResult.OK)
            {
                richTextBox1.Text = dlg.TextBoxValue;
            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (m_dlg == null)
            {
                m_dlg = new Form2(richTextBox1.Text);
                m_dlg.TextBoxChanged += new EventHandler<Form2.UpdataEventArgs>(m_dlg_textboxchanged);
                m_dlg.FormClosed += new FormClosedEventHandler(
                    (sender2, e2) => { m_dlg = null; }
                );
                m_dlg.Show(this);
            }
            else
            {
                m_dlg.Activate();
            }

        }
        private void m_dlg_textboxchanged(object sender1, Form2.UpdataEventArgs e1)
        {
            richTextBox1.Text = e1.texBox;
        }

    }
}

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;

namespace WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2(string str)
        {
            InitializeComponent();
            TextBoxValue = str;

        }
        public event EventHandler<UpdataEventArgs> TextBoxChanged;

        private void Form2_Load(object sender, EventArgs e)
        {

        }
        public string TextBoxValue
        {
            get { return textBox1.Text; }
            set { textBox1.Text = value; }
        }
        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged_1(object sender, EventArgs e)
        {
            if (TextBoxChanged != null)
            {
                UpdataEventArgs ex = new UpdataEventArgs();
                ex.texBox = textBox1.Text;
                TextBoxChanged(this, ex);
            }
        }
        public class UpdataEventArgs:EventArgs
        {
            public string texBox;
        }


    }
}