C#窗口之间传值

public partial class Form9 : Form
    {
        public Form9()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form10 fm = new Form10();
            fm.SendData += new EventHandler(fm_SendData);
            fm.ShowDialog();
        }

        void fm_SendData(object sender, EventArgs e)
        {
          //注意这里，要理解sender的意义
            Form10 FM = sender as Form10;
        //获得了值
            string info = FM.S;
            label1.Text = info;
        }
    }


这是F2里面的代码

  
public partial class Form10 : Form
    {
        public Form10()
        {
            InitializeComponent();
        }
        public event EventHandler SendData=null;
        private string s = "传送的数据";

        public string S
        {
            get { return s; }
        }

        private void OnClosed() 
        {
            if (SendData!=null)
            {
              //this把自身传递出去，F1的sender才能得到值
                SendData(this, EventArgs.Empty);
            }
        }
    

        private void Form10_FormClosed(object sender, FormClosedEventArgs e)
        {
//在关闭的时候触发事件
            OnClosed();
        }
    }