DataBinder Class (System.Web.UI)

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Classic
Lightweight
ScriptFree
.NET Framework Class Library
DataBinder Class

Provides support for rapid application development (RAD) designers to generate and parse data-binding expression syntax. This class cannot be inherited.

Inheritance Hierarchy
System.Object
  System.Web.UI.DataBinder

Namespace:  System.Web.UI
Assembly:  System.Web (in System.Web.dll)
Syntax
Visual Basic
Public NotInheritable Class DataBinder
C#
public sealed class DataBinder
Visual C++
public ref class DataBinder sealed
F#
[<Sealed>]
type DataBinder =  class end

The DataBinder type exposes the following members.

Constructors
  Name Description
Public method DataBinder Infrastructure. Initializes a new instance of the DataBinder class.
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Properties
  Name Description
Public property Static member EnableCaching Gets or sets a value that indicates whether data caching is enabled at run time.
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Methods
  Name Description
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Public method Static member Eval(Object, String) Evaluates data-binding expressions at run time.
Public method Static member Eval(Object, String, String) Evaluates data-binding expressions at run time and formats the result as a string.
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method Static member GetDataItem(Object) Retrieves an object's declared data item.
Public method Static member GetDataItem(Object, Boolean) Retrieves an object's declared data item, indicating success or failure.
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method Static member GetIndexedPropertyValue(Object, String) Retrieves the value of a property of the specified container and navigation path.
Public method Static member GetIndexedPropertyValue(Object, String, String) Retrieves the value of the specified property for the specified container, and then formats the results.
Public method Static member GetPropertyValue(Object, String) Retrieves the value of the specified property of the specified object.
Public method Static member GetPropertyValue(Object, String, String) Retrieves the value of the specified property of the specified object, and then formats the results.
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
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Remarks

You can use the overloaded static Eval method of this class in data-binding syntax in an ASP.NET Web page. This provides an easier syntax to work with than standard data binding. However, because DataBinder.Eval provides automatic type conversion, it can result in slower performance.

For more information about ASP.NET data binding, expressions, and syntax, see Binding to Databases and Data-Binding Expressions Overview.

Examples

The following example uses the static GetPropertyValue method to populate the fields of a Repeater control using an ArrayList of Product objects. The Eval method could be applied with the same syntax, but it would not perform as quickly.

This example uses a custom Product class which exposes a string Model property and a numeric UnitPrice property.

Visual Basic

<%@ Page Language="vb" %>
<%@ Import Namespace="ASPSample" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    Private Sub Page_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load

        ' Create and populate an ArrayList to store the products.
        Dim ProductList As New ArrayList
        ProductList.Add(New Product("Standard", 99.95))
        ProductList.Add(New Product("Deluxe", 159.95))

        ' Bind the array list to Repeater
        ListRepeater.DataSource = ProductList
        ListRepeater.DataBind()

    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
	<title>DataBinder Example</title>
</head>
<body>
<form id="Form2" runat="server">
<table>
<asp:Repeater id="ListRepeater" runat="server">
    <HeaderTemplate>
	<tr>
		<th style="width:50; text-align:left">Model</th>
		<th style="width:100; text-align:right">Unit Price</th>
	</tr>
	</HeaderTemplate>
	<ItemTemplate>
    <tr>
        <!-- Databind to the Product information using the DataBinder methods. 
             The Container.DataItem refers to the ArrayList object bound to 
             the ASP:Repeater in the Page Load event. -->
	    <td>
	        <%#DataBinder.GetPropertyValue(Container.DataItem, "Model")%>
	    </td>
	    <!-- Format the UnitPrice as currency. ({0:c}) -->
	    <td style="text-align:right">
	        <%#DataBinder.GetPropertyValue(Container.DataItem, _
	                     "UnitPrice", "{0:c}")%>
	    </td>
    </tr>
	</ItemTemplate>
</asp:Repeater>
</table>
</form>
</body>
</html>
C#

<%@ Page Language="C#" %>
<%@ Import Namespace="ASPSample" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void  Page_Load(object sender, EventArgs e)
{
        // Create and populate an ArrayList to store the products.
        ArrayList ProductList = new ArrayList();
        ProductList.Add(new Product("Standard", 99.95));
        ProductList.Add(new Product("Deluxe", 159.95));

        // Bind the array list to Repeater
        ListRepeater.DataSource = ProductList;
        ListRepeater.DataBind();
}
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
	<title>DataBinder Example</title>
</head>
<body>
<form id="Form2" runat="server">
<table>
<asp:Repeater id="ListRepeater" runat="server">
    <HeaderTemplate>
	<tr>
		<th style="width:50; text-align:left">Model</th>
		<th style="width:100; text-align:right">Unit Price</th>
	</tr>
	</HeaderTemplate>
	<ItemTemplate>
    <tr>
        <!-- Databind to the Product information using the DataBinder methods. 
             The Container.DataItem refers to the ArrayList object bound to 
             the ASP:Repeater in the Page Load event. -->
	    <td>
	        <%#DataBinder.GetPropertyValue(Container.DataItem, "Model")%>
	    </td>
	    <!-- Format the UnitPrice as currency. ({0:c}) -->
	    <td style="text-align:right">
	        <%#DataBinder.GetPropertyValue(Container.DataItem,
	                     "UnitPrice", "{0:c}")%>
	    </td>
    </tr>
	</ItemTemplate>
</asp:Repeater>
</table>
</form>
</body>
</html>

The following code is the custom Product class. This code should be included in a separate class file in the App_Code directory, such as Product.cs or Product.vb.

Visual Basic

Namespace ASPSample

    Public Class Product
        Private _Model As String
        Private _UnitPrice As Double

        ' The product Model.
        Public Property Model() As String
            Get
                Return _Model
            End Get
            Set(ByVal Value As String)
                _Model = Value
            End Set
        End Property

        ' The price of the each product.
        Public Property UnitPrice() As Double
            Get
                Return _UnitPrice
            End Get
            Set(ByVal Value As Double)
                _UnitPrice = Value
            End Set
        End Property


        Public Sub New(ByVal Model As String, ByVal UnitPrice As Double)
            _Model = Model
            _UnitPrice = UnitPrice
        End Sub

    End Class

End Namespace
C#

namespace ASPSample
{

    public class Product
    {
        string _Model;
        double _UnitPrice;

        public Product(string Model, double UnitPrice)
        {
            _Model = Model;
            _UnitPrice = UnitPrice;
        }

        // The product Model.
        public string Model
        {
            get {return _Model;}
            set {_Model = value;}
        }

        // The price of the each product.
        public double UnitPrice
        {
            get {return _UnitPrice;}
            set {_UnitPrice = value;}
        }
    }
}
Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also

Reference

System.Web.UI Namespace
XPathBinder
IBindableTemplate

Other Resources

Data-Binding Expression Syntax
ASP.NET Data Access