DisplayFormatAttribute Class

Definition

Namespace:

System.ComponentModel.DataAnnotations

Assembly:

System.ComponentModel.Annotations.dll

Source:

DisplayFormatAttribute.cs

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

public ref class DisplayFormatAttribute : Attribute

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

[<System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Property, AllowMultiple=false)>]
type DisplayFormatAttribute = class
    inherit Attribute

Public Class DisplayFormatAttribute
Inherits Attribute

Inheritance

Object

Attribute

DisplayFormatAttribute

Attributes

AttributeUsageAttribute

Examples

See an online 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;

[MetadataType(typeof(ProductMetaData))]
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.
    [DisplayFormat(DataFormatString="{0:C}")]
    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;
}

Imports System.Web.DynamicData
Imports System.ComponentModel.DataAnnotations


<MetadataType(GetType(ProductMetaData))> _
Partial Public Class Product

End Class

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 Size As Object

    ' Display currency data field in the format such as $1,345.50.
    <DisplayFormat(DataFormatString:="{0:C}")> _
    Public StandardCost As Object

    ' Display date data field in the short format such as 11/12/08.
    ' Also, apply format in edit mode.
    <DisplayFormat(ApplyFormatInEditMode:=True, DataFormatString:="{0:d}")> _
    Public SellStartDate As Object

End Class

To compile the example, you need the following:

• Any edition of Visual Studio 2010 or later.

• 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 GitHub. Make sure that you install the correct version of the sample database for the version of SQL Server that you are running.

• 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.

Remarks

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.

Constructors

DisplayFormatAttribute()

Initializes a new instance of the DisplayFormatAttribute class.

Properties

ApplyFormatInEditMode	Gets or sets a value that indicates whether the formatting string that is specified by the DataFormatString property is applied to the field value when the data field is in edit mode.
ConvertEmptyStringToNull	Gets or sets a value that indicates whether empty string values ("") are automatically converted to null when the data field is updated in the data source.
DataFormatString	Gets or sets the display format for the field value.
HtmlEncode	Gets or sets a value that indicates whether the field should be HTML-encoded.
NullDisplayText	Gets or sets the text that is displayed for a field when the field's value is null.
NullDisplayTextResourceType	Gets or sets the Type that contains the resources for NullDisplayText. Using NullDisplayTextResourceType along with NullDisplayText, allows the GetNullDisplayText() method to return localized values.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute)
GetHashCode()	Returns the hash code for this instance. (Inherited from Attribute)
GetNullDisplayText()	Returns the UI display string for NullDisplayText.
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

See also

• How to: Set the Culture and UI Culture for ASP.NET Web Page Globalization