子窗体调用父窗体(转)

///////////////////////////////////////////////////////////////////////
///// 父窗体,你需要添加一个button(并关联button1_Click)和一个textbox
///////////////////////////////////////////////////////////////////////
using System;
using System.Windows.Forms;

namespace Demo
{ 
    public partial class ParentForm : Form
    {
        ChildForm childForm;
        public ParentForm()
        {
            InitializeComponent();            
        }
        
        private void button1_Click(object sender, EventArgs e)
        {
             childForm= new ChildForm();
             childForm.DataArrivalEvent+=new ChildForm.DataArrivalEventHandler(childForm_DataArrivalEvent);
             //显示子窗体
             childForm.ShowDialog();
        }

        //事件处理
        void childForm_DataArrivalEvent(string msg)
        {
            textBox1.Text = msg;
        }
    }
}
///////////////////////////////////////////////////////////////////////
///// 子窗体 你需要添加一个button,并关联button1_Click
///////////////////////////////////////////////////////////////////////
using System;
using System.Windows.Forms;

namespace Demo
{
    public partial class ChildForm : Form
    {
        //接收信息事件委托
        public delegate void DataArrivalEventHandler(string msg);
        //事件对象
        public event DataArrivalEventHandler DataArrivalEvent;

        static int clickCount = 0;

        public ChildForm()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //如果父窗体已注册了自定义事件
            if (DataArrivalEvent != null)
            {
                DataArrivalEvent(String.Format("单击:{0}次", clickCount++));
            }
        }
    }
}