C#替控件增加或删除委托

protected void Page_Load(object sender, EventArgs e)
        {
            if (!Biz.Process.IsTobe(pId))
            {
                this.btnDetermine.Click -= new System.EventHandler(btnDetermine_Click);
                this.btnDetermine.Click += new System.EventHandler(btnCancel_Click);
            }
        }

        protected void btnDetermine_Click(object sender, EventArgs e)
        {
            
        }

        protected void btnCancel_Click(object sender, EventArgs e)
        {
            
        }