When should I use simple binding vs complex binding?
Use simple binding for one value in a single control. Use complex binding for lists and grids where multiple rows are shown.
ASP.NET Data Binding: Simple vs Complex (with Examples)
What Data Binding Does
Data binding links values from a data source to UI controls so users can see and edit data. In ASP.NET Web Forms you use two common styles: simple binding for a single value, and complex binding for lists and tables.
Simple Binding
Simple binding connects one value to a control such as a Label or TextBox. You can bind at design time with expressions or at runtime by setting properties and calling DataBind.
Bind a single value
Complex Binding
Complex binding connects a list of rows to controls like ListBox, DropDownList, GridView, or Repeater. You set the data source (for example a DataTable or a LINQ query), choose the text/value fields, and call DataBind to render.
ListBox binding
// Data source: a list or DataTable
List data = GetCategories();
ListBox1.DataSource = data;
ListBox1.DataTextField = "Name";
ListBox1.DataValueField = "Id";
ListBox1.DataBind();
GridView with template
<%# (bool)Eval("Active") ? "Yes" : "No" %>
// Code-behind
GridView1.DataSource = GetCategories();
GridView1.DataBind();Design-Time vs Runtime
When you add bindings in Visual Studio, the .aspx markup gets data binding expressions. At runtime ASP.NET evaluates those expressions when DataBind runs and places values into controls. In older Windows Forms apps a CurrencyManager tracked the current record; in Web Forms the page rebinding cycle uses DataSource controls or your code to provide the current data.
Rebind after changes
// After you change data, refresh the bound controls
SaveChanges();
Page.DataBind(); // or GridView1.DataBind();Practical Notes
Keep bindings readable. Prefer field names that make sense, and avoid heavy logic in the markup. For lists, set DataTextField and DataValueField. For templates, use Eval or Bind as needed.
FREQUENTY ASKED QUESTIONS (FAQ)
How do I refresh data after saving?
Update the data source, then call DataBind on the control or the whole Page to evaluate binding expressions again.