When working with Databound controls, very often we are required to work with templates, may be they are ItemTemplates, EditItemTemplates, InsertItemTemplates etc. In these situations usually we’ll use data-binding expressions.
There are 3 types of commonly used Data-binding expressions.
1. Type I – <%# Eval(“column_name”) %>
The above expression is a 2-way expression, meaning you can read/write values. Commonly used in TextBoxes.
<asp:TextBox text = ‘<%# Eval(“LastName”) %>
2. Type II – <%# Bind(column_name) %>
The above expression is a 1-way expression, meaning you can only read values. Commonly used in DropDownLists, Listboxes, labels.
<asp:DropDownList SelectedValue = <%# Bind(“LastName”) %>
3. Type III – <%# Function() || variable %>
Examples: <%# SomeMethod() %>
<%# firstName %>
<%# (firstname)+’ ‘+(lastname) %>
Reference: http://msdn.microsoft.com/en-us/library/ms178366(VS.80).aspx, http://bhaidar.net/cs/archive/2006/08/04/473.aspx
Tags: Bind, Databinding expressions, Eval
