using System;
using System.Timers;
namespace TianYiHeWenQi
{
  class HewenqiTianyi
  {
    public static event ActionEventHandler HoverTreeWindEvent;
    WindEventArgs _arg = new WindEventArgs();
    public HewenqiTianyi()
    {
      Timer h_timer = new Timer();
      h_timer.Interval = 3000;
      h_timer.Elapsed += H_timer_Elapsed;
      h_timer.Start();
    }
    Random _HoverClock=new Random ();
    private void H_timer_Elapsed(object sender, ElapsedEventArgs e)
    {
      _arg.WindType = (WindDdirection)(_HoverClock.Next(3));
      OnAction(_arg);
    }
    protected void OnAction(WindEventArgs ev)
    {
      HoverTreeWindEvent?.Invoke(ev);
      //相当于以下代码
      //if (HoverTreeWindEvent != null)
      //{
      //  HoverTreeWindEvent(ev);
      //}
    }
  }
  class WindEventArgs : EventArgs
  {
    public WindDdirection WindType { get; set; }
  }
  enum WindDdirection
  {
    East,
    West,
    Static
  }
  delegate void ActionEventHandler(WindEventArgs ev);
}

using System;
using System.Windows.Forms;
namespace TianYiHeWenQi
{
  public partial class HoverTreeGrass : UserControl
  {
    delegate void MySetText(string text);
    public HoverTreeGrass()
    {
      InitializeComponent();
      HewenqiTianyi.HoverTreeWindEvent += HewenqiTianyi_HoverTreeWindEvent;
    }
    private void UpdateLabel(WindDdirection wd)
    {
      if (label_grass.InvokeRequired)
      {
        // 当一个控件的InvokeRequired属性值为真时，说明有一个创建它以外的线程想访问它
        Action<WindDdirection> actionDelegate = (x) => {
          switch (x)
          {
            case WindDdirection.East:
              label_grass.Location = new System.Drawing.Point(40 - 9, label_grass.Location.Y);
              label_grass.Text="\\";
              break;
            case WindDdirection.West:
              label_grass.Location = new System.Drawing.Point(40+9, label_grass.Location.Y);
              label_grass.Text = "/";
              break;
            case WindDdirection.Static:
              label_grass.Location = new System.Drawing.Point(40, label_grass.Location.Y);
              label_grass.Text = "|";
              break;
          }
        };
        // 或者
        // Action<string> actionDelegate = delegate(string txt) { this.label_grass.Text = txt; };
        this.label_grass.BeginInvoke(actionDelegate, wd);
      }
      else
      {
        switch (wd)
        {
          case WindDdirection.East:
            label_grass.Text = "\\";
            break;
          case WindDdirection.West:
            label_grass.Text = "/";
            break;
          case WindDdirection.Static:
            label_grass.Text = "|";
            break;
        }
      }
    }
    private void HewenqiTianyi_HoverTreeWindEvent(WindEventArgs ev)
    {
      UpdateLabel(ev.WindType);
    }
  }
}

using System.Windows.Forms;
namespace TianYiHeWenQi
{
  public partial class HoverTreeForm : Form
  {
    public HoverTreeForm()
    {
      InitializeComponent();
      for (int i = 0; i < tableLayoutPanel_hovertree.ColumnCount; i++) {
        for (int j = 0; j < tableLayoutPanel_hovertree.RowCount; j++) {
          tableLayoutPanel_hovertree.Controls.Add(new HoverTreeGrass(), i, j);
        }
      }
      HewenqiTianyi h_ty = new HewenqiTianyi();
    }
  }
}