System.Web.UI Namespace DataBinder Class
Evaluates data-binding expressions at runtime and formats the result as text to be displayed in the requesting browser.
[ VB ]
Overloads Public Shared Function Eval ( _
ByVal container As Object, _
ByVal expression As String, _
ByVal format As String _
) As String
[ C# ]
public static string Eval (
object container,
string expression,
string format
);
[ C++ ]
public: static String* Eval (
Object* container,
String* expression,
String* format
);
[ JScript ]
public static function Eval (
container : Object,
expression : String,
format : String
) : String;
- container
- The object reference against which the expression is evaluated. This must be a valild object identifier in the page's specified language.
- expression
- The navigation path from the container to the property value to be placed in the bound control property. This must be a string of property or field names separated by dots.
- format
- A .NET Framework format string used to convert the object, which results from the evaluation of the data binding expression, to a string type to be displayed by the requesting browser.
The text that results from the evaluation of the data binding expression and conversion to a string type. This will be displayed by the requesting browser.
While this method is automatically called when you create data bindings in a RAD designer, you can also use it declaratively if you want to simplify the casting to a text string to be displayed on a browser. To do so, you must place the <%#
and %>
tags, which are also used in standard ASP.NET data binding, around the data binding expression.
This method is particularly useful when data binding against controls that are in a templated list.
CAUTION: Since this method is called at runtime, it can cause performance to noticeably slow compared to standard ASP.NET databinding syntax. Use this method judiciously, particularly when string formatting is not required.
For any of the list Web controls, such as DataList, DataGrid, or Repeater, the container parameter should be Container.DataItem. If you are binding against the page, the container parameter should be Page.
The following example demonstrates how you can use the Eval method to declaratively bind to a Price field. This example uses container syntax that assumes you are using one of the list Web server controls. The format parameter formats the number as a locale-specific currency string that will be displayed by the requesting browser.
<%# DataBinder.Eval ( Container.DataItem, "Price", "{0:c}" %>
DataBinder Members DataBinder.Eval Overload List Data Binding Expression Syntax