UpdatePanel控件也是Ajax里用得最多的控件之中的一个，UpdatePanel控件是用来局部更新网页上的内容，网页上要局部更新的内容必须放在UpdatePanel控件里，他必须和上一次说的ScriptManager控件一起使用。如今来看UpdatePanel的属性
protected void Button1_Click1( object sender, EventArgs e)
{ 
SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=;database=pubs"); string sql1 = "select top 5 au_lname from authors "; SqlDataAdapter myAdapter = new SqlDataAdapter(sql1, conn); DataSet ds = new DataSet(); myAdapter.Fill(ds, "bieminG"); //来自web service的dataset,这里随便一个ds就能够; this.GridView1.DataSource = ds.Tables["bieminG"].DefaultView; ; this.GridView1.DataBind(); //数据绑定
} protected void Button2_Click( object sender, EventArgs e) { this.Label1.Text = "11111"; } Button1实现一个数据集的异步更新，BUTTON2就是一般的赋值了。看看是不是非常easy呀！呵呵！
UpdatePanel 重要的属性例如以下：
| 属性 | 说明 |
| ChildrenAsTriggers | 当UpdateMode属性为Conditional时，UpdatePanel中的子控件的异步回送是否会引发UpdatePanle的更新。 |
| RenderMode | 表示UpdatePanel终于呈现的HTML元素。Block（默认）表示<div>，Inline表示<span> |
| UpdateMode | 表示UpdatePanel的更新模式，有两个选项：Always和Conditional。Always是无论有没有Trigger，其它控件都将更新该UpdatePanel，Conditional表示仅仅有当前UpdatePanel的Trigger，或ChildrenAsTriggers属性为true时当前UpdatePanel中控件引发的异步回送或者整页回送，或是server端调用Update()方法才会引发更新该UpdatePanel。 |
ChildrenAsTriggers：当UpdateMode属性为Conditional时，UpdatePanel中的子控件的异步回送是否会引发UpdatePanle的更新。
里面包括了一个Triggers,里面第一个属性 AsyncPostBackTrigger指定Button1实现异步更新，而PostBackTrigger指定Button2实现整页更新。.CS代码为： RenderMode:表示UpdatePanel终于呈现的HTML元素。Block（默认）表示<div>，Inline表示<span> <% @ Page Language = " C# " AutoEventWireup = " true " CodeFile = " Default.aspx.cs " Inherits = " _Default " %> <! DOCTYPE html PUBLIC " -//W3C//DTD XHTML 1.1//EN " " http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd " > < html xmlns = " http://www.w3.org/1999/xhtml " > < head runat = " server " > < title > Untitled Page </ title > < style type = " text/css " > body { background-attachment:fixed; background-image:url(Blue hills.jpg); } .style1 { background-position:top center; } </ style > </ head > < body onload = " oSpan.className='style1' " > < form id = " form1 " runat = " server " > < span style = " font-size:14; width:250; " ID = " oSpan " onmouseover = " this.className='style2' " onmouseout = " this.className='style1' " ></ span > < div > < asp:ScriptManager ID = " ScriptManager1 " runat = " server " > </ asp:ScriptManager > </ div > < asp:UpdatePanel ID = " uid " runat = " server " > < ContentTemplate > < div > < asp:Button ID = " Button1 " runat = " server " Text = " 异步回送 " OnClick = " Button1_Click1 " />& nbsp; & nbsp; < asp:Button ID = " Button2 " runat = " server " Text = " 整页回送 " OnClick = " Button2_Click " />< br /> < asp:GridView ID = " GridView1 " runat = " server " AutoGenerateColumns = " False " Width = " 197px " > < Columns > < asp:BoundField DataField = " au_lname " FooterText = " aaaa " HeaderText = " au_lname " /> </ Columns > </ asp:GridView > < br /> < asp:Label ID = " Label1 " runat = " server " Text = " 当前时间 " Font - Bold = " True " Font - Size = " Large " ></ asp:Label > </ div > </ ContentTemplate > < Triggers > < asp:AsyncPostBackTrigger ControlID = " Button1 " /> < asp:PostBackTrigger ControlID = " Button2 " /> </ Triggers > </ asp:UpdatePanel > < div id = " div1 " > & nbsp; </ div > </ form > </ body > </ html >
UpdateMode：表示UpdatePanel的更新模式，有两个选项：Always和Conditional。Always是无论有没有Trigger，其它控件都将更新该UpdatePanel，Conditional表示仅仅有当前UpdatePanel的Trigger，或ChildrenAsTriggers属性为true时当前UpdatePanel中控件引发的异步回送或者整页回送，或是server端调用Update()方法才会引发更新该UpdatePanel。 Contente Template：用来定义UpdatePanel的内容Triggers：分别为AsyncPostBackTrigger和PostBackTriggerAsyncPostBackTrigge用来指定某个server端控件以及其将触发的server端事件作为该UpdatePanel的异步更新触发器，它须要设置的属性有控件ID和服务端控件的事件；PostBackTrigger用来指定在UpdatePanel中的某个服务端控件，它所引发的回送不使用异步回送，而仍然是传统的整页回送如今我们来做一个简单的实例：
<% @ Page Language = " C# " AutoEventWireup = " true " CodeFile = " Default.aspx.cs " Inherits = " _Default " %> <! DOCTYPE html PUBLIC " -//W3C//DTD XHTML 1.1//EN " " http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd " > < html xmlns = " http://www.w3.org/1999/xhtml " > < head runat = " server " > < title > Untitled Page </ title > < style type = " text/css " > body { background-attachment:fixed; background-image:url(Blue hills.jpg); } .style1 { background-position:top center; } </ style > </ head > < body onload = " oSpan.className='style1' " > < form id = " form1 " runat = " server " > < span style = " font-size:14; width:250; " ID = " oSpan " onmouseover = " this.className='style2' " onmouseout = " this.className='style1' " ></ span > < div > < asp:ScriptManager ID = " ScriptManager1 " runat = " server " > </ asp:ScriptManager > </ div > < asp:UpdatePanel ID = " uid " runat = " server " > < ContentTemplate > < div > < asp:Button ID = " Button1 " runat = " server " Text = " 异步回送 " OnClick = " Button1_Click1 " />& nbsp; & nbsp; < asp:Button ID = " Button2 " runat = " server " Text = " 整页回送 " OnClick = " Button2_Click " />< br /> < asp:GridView ID = " GridView1 " runat = " server " AutoGenerateColumns = " False " Width = " 197px " > < Columns > < asp:BoundField DataField = " au_lname " FooterText = " aaaa " HeaderText = " au_lname " /> </ Columns > </ asp:GridView > < br /> < asp:Label ID = " Label1 " runat = " server " Text = " 当前时间 " Font - Bold = " True " Font - Size = " Large " ></ asp:Label > </ div > </ ContentTemplate > < Triggers > < asp:AsyncPostBackTrigger ControlID = " Button1 " /> < asp:PostBackTrigger ControlID = " Button2 " /> </ Triggers > </ asp:UpdatePanel > < div id = " div1 " > & nbsp; </ div > </ form > </ body > </ html > 表示UpdatePanel终于呈现的HTML元素。Block（默认）表示<div>，Inline表示<span>
protected void Button1_Click1( object sender, EventArgs e) { SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=;database=pubs"); string sql1 = "select top 5 au_lname from authors "; SqlDataAdapter myAdapter = new SqlDataAdapter(sql1, conn); DataSet ds = new DataSet(); myAdapter.Fill(ds, "bieminG"); //来自web service的dataset,这里随便一个ds就能够; this.GridView1.DataSource = ds.Tables["bieminG"].DefaultView; ; this.GridView1.DataBind(); //数据绑定 } protected void Button2_Click( object sender, EventArgs e) { this.Label1.Text = "11111"; }