c# 委托模板 用来 更新控件，控件线程占用问题

    public class AppEvents
    {

        private static AppEvents instance = null;
        private AppEvents()
        {
        }
        public static AppEvents Instance
        {
            get
            {
                if (instance == null)
                    instance = new AppEvents();

                return instance;
            }
        }
        public delegate void UpdateScreenEventHandler(string msg);  //委托声明 sunjie 1
        public delegate void UpdateConnectionStatusEventHandler(AgentStatus status);

        public UpdateScreenEventHandler OnUpdateScreenRun;   //创建委托对象 sunjie 2
        public UpdateConnectionStatusEventHandler OnUpdateConnectionStatusRun;

        public event UpdateScreenEventHandler UpdateScreenEvent
        {
            add
            {
                OnUpdateScreenRun = (UpdateScreenEventHandler)System.Delegate.Combine(OnUpdateScreenRun, value);
            }
            remove
            {
                OnUpdateScreenRun = (UpdateScreenEventHandler)System.Delegate.Remove(OnUpdateScreenRun, value);
            }
        }
        public event UpdateConnectionStatusEventHandler UpdateConnectionStatusEvent
        {
            add
            {
                OnUpdateConnectionStatusRun = (UpdateConnectionStatusEventHandler)Delegate.Combine(OnUpdateConnectionStatusRun, value);
            }
            remove
            {
                OnUpdateConnectionStatusRun = (UpdateConnectionStatusEventHandler)Delegate.Remove(OnUpdateConnectionStatusRun, value);
            }
        }
    }

        private delegate void RefreshAgentStatus(AgentStatus status);
        private delegate void FlushOutPut(string msg);

      private void InitializeEvents()
        {
            AppEvents.Instance.UpdateConnectionStatusEvent += UpdateStatus;
            AppEvents.Instance.UpdateScreenEvent += LogToScreen;
        }

       public void UpdateStatus(AgentStatus status)
        {
            if (lbStatus.InvokeRequired)
            {
                var refresh = new RefreshAgentStatus(UpdateStatus);
                this.Invoke(refresh, new object[] { status });
            }
            else
            {
                if (status == AgentStatus.ONLINE)
                {
                    if (!string.Equals(lbStatus.Text, status.ToString()))
                    {
                        lbStatus.Text = status.ToString();
                        lbStatus.BackColor = System.Drawing.Color.LimeGreen;
                        lbStatus.ForeColor = System.Drawing.Color.Black;
                    }
                }
                else
                {
                    if (status == AgentStatus.ERROR || status == AgentStatus.OFFLINE)
                    {
                        if (!string.Equals(lbStatus.Text, status.ToString()))
                        {
                            lbStatus.Text = status.ToString();
                            lbStatus.BackColor = System.Drawing.Color.Red;
                            lbStatus.ForeColor = System.Drawing.Color.White;
                        }
                    }
                    else
                    {
                        //lbStatus.Text = status.ToString();
                        //lbStatus.BackColor = System.Drawing.Color.LimeGreen;
                        //lbStatus.ForeColor = System.Drawing.Color.Black;
                    }
                }
            }
        }
        private void LogToScreen(string st)
        {
            if (this.richLog.InvokeRequired)
            {
                var flush = new FlushOutPut(LogToScreen);
                this.Invoke(flush, new object[] { st });
            }
            else
            {
                var msg = string.Format("{0}   {1}", DateTime.Now.ToString(Settings.NormalDateTimeFormatDash), st);

                if (richLog.Text.Length >= 500)
                {
                    var index = richLog.Text.Length;
                    richLog.Text = (st + "
" + richLog.Text).Substring(0, 500);
                }
                else
                {
                    richLog.Text = (st + "
" + richLog.Text);
                }
            }
        }

        private void writeLogToText(string strlog = "")
        {
            AppEvents.Instance.OnUpdateScreenRun(strlog);
            //richLog.Text = richLog.Text + strlog + "  
";
        }