如何动态地将触发器添加到动态创建的控件中

Question

我已经在asp.net webforms中以编程方式创建了一堆html元素，并且在我的aspx页面上有一个UpdatePanel。现在我想为每个创建的元素点击事件添加触发器。

这是我的代码

string content = "";
int i = 1000;

string btnRight = "";
string btnLeft = "";

GroupsRepository gr = new GroupsRepository();

List<Group> groups = new List<Group>();
groups = gr.LoadListAllGroups();

foreach (Group gp in groups)
{
    btnLeft = "<button class='btnLeftService'  runat='server' value='مقالات' />";
    btnRight = "<button class='btnRightService' id='" + gp.GroupID.ToString() + "' runat='server' onserverclick='subGroups_ServerClick' value='زیر گروه ها' />";
    content += "<div  class='item'>";
    content += "<div class='row m0 service '><div class='row m0 innerRow item'><div><i class='fa fa-laptop'></i><div class='serviceName'>" + gp.Title + "</div></div><div class='item-overlay left'><ul><li class='liLeft'>" + btnLeft + "</li><li class='liRight'>" + btnRight + "</li></ul></div></div></div>";
    i++;
}

ourServises.InnerHtml = content;

GroupsRepository gr = new GroupsRepository();

List<Group> groups = new List<Group>();
groups = gr.LoadListAllGroups();

foreach (Group gp in groups)
{
     AsyncPostBackTrigger trigger = new AsyncPostBackTrigger();
     trigger.ControlID = gp.GroupID.ToString();
     trigger.EventName = "Click";
     updatepanel2.Triggers.Add(trigger);
}

但在运行时，我收到此错误：

  

ID为＆＃39; 1＆＃39;在UpdatePanel＆quot; updatepanel2＆＃39;。

中找不到触发器

我该怎么办？