Difference between Eval and Bind - Data Binding Expressions in ASP.NET

In simple words, the Eval function is used to define one-way binding (read only). The Bind function is used for two-way binding (read-write)

So in a control like the GridView or the FormView, when you have to display read only data using a label control, you would be using the Eval function whereas when you want to update a database field, you would be using a TextBox and thus using the Bind function.

Note: You can use the Bind function to retrieve the value of a databound field, just as Eval does.

Here’s an example:

<asp:FormView ID="FormView1" runat="server"
 AllowPaging="True"
 DataKeyNames="CustomerID"
 DataSourceID="SqlDataSource1">       
     <EditItemTemplate>
         CustomerName:
         <asp:TextBox ID="txtCustName"
             runat="server"
             Text='<%# Bind("CName") %>'>
         </asp:TextBox>
     </EditItemTemplate>
    
     <ItemTemplate>
         CustID:
         <asp:Label ID="lblCustID"
             runat="server"
             Text='<%# Eval("CID") %>'>
         </asp:Label>
     </ItemTemplate>
 </asp:FormView>

You can read more on the Eval and Bind functions

Bookmark this link on del.icio.us (saved by 0 users)

Did you like this post?

	subscribe via rss		subscribe via e-mail
	print this post		follow me on twitter

Others Also Read..