Eval是1.1中常 用的绑定语法,它是“单向”的,即绑定时把数据源上相应的值赋到该控件上,Eval的任务就完成了
而Bind所谓的“双向”就是:在绑定时,把 数据源上相应的值赋到该控件上,并且,在提交时,自动提取用户在该控件上输入的值。
Code
< EditItemTemplate >
< asp:Label ID ="CityIDLabel1" runat ="server" Text ='<%# Eval("CityID")% > '> </ asp:Label >
< asp:TextBox ID ="CityTextBox" runat ="server" Text ='<%# Bind("City")% > '> </ asp:TextBox >
</ EditItemTemplate >
又例:
Eval:绑定的是只读数据的显 示;Bind:可以绑定只读数据也可以绑定更新数据,Bind方法还把字段和控件的绑定属性联系起来,使得数据控件(比如GridView等)的 Update、Insert和Delete等方法可以使用这种联系来作出相应的处理。
Eval 和 Bind绑定的数据在<%# %> 显示, 若对要显示的数据作修改或者操作也在<%# %> 中,例如:
1, 对显示的字符串作字符显示:
<% #( Eval ( " Address " )).ToString().SubString( 0 , 10 ) %>
显 示10位数的地址。
2, 对显示的信息作判断:
<% #( Eval ( " if_delete " )).ToString == " yes " ? " 已删 除 " : " 未删除 " %>
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<% %> An embedded code block is server code that executes during the page's render phase. The code in the block can execute programming statements and call functions in the current page class. /en-gb/library/ms178135(vs.80).aspx
<%= %> most useful for displaying single pieces of information. /en-us/library/6dwsdcf5(VS.71).aspx
<%# %> Data Binding Expression Syntax. /en-us/library/bda9bbfx.aspx
<%$ %> Expression. /en-us/library/d5bd1tad.aspx
<%@ %> Directive Syntax. /en-us/library/xz702w3e(VS.80).aspx
<%-- --%> Server-Side Comments. /en-US/library/4acf8afk.aspx