在窗体放一个lable 二个控件 代码如下 protected void Button1_Click(object sender, EventArgs e) ...{ Type scriptManagerType =Type.GetType("System.Web.UI.ScriptManager, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35",false); if (scriptManagerType != null) ...{ Label1.Text="ASP.NET AJAX is installed";} else ...{ Label1.Text="ASP.NET AJAX is not installed.";} } protected void Button2_Click(object sender, EventArgs e) ...{ ScriptManager sm = ScriptManager.GetCurrent(Page); if (sm != null) ...{ Label1.Text = "yes 存在"; } else ...{ Label1.Text = "no 没有"; }