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DisplayFormatAttribute Class

Updated: July 2008

Specifies how data fields are displayed and formatted by ASP.NET Dynamic Data.

Namespace:  System.ComponentModel.DataAnnotations
Assembly:  System.ComponentModel.DataAnnotations (in System.ComponentModel.DataAnnotations.dll)

[AttributeUsageAttribute(AttributeTargets.Property|AttributeTargets.Field, AllowMultiple = false)]
public class DisplayFormatAttribute : Attribute

When you apply this attribute to a data field, you must follow the guidelines for the use of the attributes. For more information, see ASP.NET Dynamic Data Guidelines.

See a run-time code example of this feature: Run.

The following example shows how to use the DisplayFormatAttribute to customize formatting for a data field. The example performs the following steps:

  • Implements a metadata partial class and an associated metadata class.

  • In the associated metadata class, it applies the DisplayFormatAttribute attribute to specify the following results:

    • Display the text "[Null]" when a data field is empty.

    • Display currency data in locale specific currency format.

    • Display date information in short format (mm/dd/yy). This format also applies in edit mode.

using System;
using System.Web.DynamicData;
using System.ComponentModel.DataAnnotations;

public partial class Product


public class ProductMetaData

    // Applying DisplayFormatAttribute 
    // Display the text [Null] when the data field is empty. 
    // Also, convert empty string to null for storing.
    [DisplayFormat(ConvertEmptyStringToNull = true, NullDisplayText = "[Null]")]
    public object Size;

    // Display currency data field in the format $1,345.50.
    public object StandardCost;

    // Display date data field in the short format 11/12/08. 
    // Also, apply format in edit mode.
    [DisplayFormat(ApplyFormatInEditMode=true, DataFormatString = "{0:d}")]
    public object SellStartDate;

To compile the example, you need the following:

  • Microsoft Visual Studio 2008 Service Pack 1 or Visual Web Developer 2008 Express Edition Service Pack 1.

  • The AdventureWorksLT sample database. For information about how to download and install the SQL Server sample database, see Microsoft SQL Server Product Samples: Database on the CodePlex site. Make sure that you install the correct version of the sample database for the version of SQL Server that you are running (Microsoft SQL Server 2005 or Microsoft SQL Server 2008).

  • A data-driven Web site. This enables you to create a data context for the database and the class that contains the data field to customize. For more information, see Walkthrough: Creating a New Dynamic Data Web Site using Scaffolding.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5 SP1




July 2008

Added topic for new class.

SP1 feature change.