Language

DataKeyCollection Class

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Represents a collection that contains the key field of each record in a data source. This class cannot be inherited.

public ref class DataKeyCollection sealed : System::Collections::ICollection
public sealed class DataKeyCollection : System.Collections.ICollection
type DataKeyCollection = class
    interface ICollection
    interface IEnumerable
Public NotInheritable Class DataKeyCollection
Implements ICollection
Inheritance
Object
DataKeyCollection
Implements
ICollection IEnumerable

Examples


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>





    BaseDataList DataKeys Example






   


      
BaseDataList DataKeys Example


      

         

            

         

      

   






<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>





    BaseDataList DataKeys and DataKeyField Example






   


      
BaseDataList DataKeys and DataKeyField Example

Remarks

The DataKeyCollection class represents a collection of the key fields in the data source. The key field of each record in the data source is stored in this collection. This allows you to store the key field with a data listing control without displaying it in the control. This collection is automatically filled with the values from the field specified by the BaseDataList.DataKeyField property. This collection does not allow you to manually add or remove items from the collection.

The key field is commonly used in a handler for an event, such as ItemCommand or DeleteCommand, as part of an update query string to revise a specific record in the data source. The key field helps the update query string identify the appropriate record to modify.

Use the Count property to determine the number of items in the collection. To programmatically retrieve a key field from a DataKeyCollection, use one of following methods:

  • Use the indexer to get a single key field from the collection, using array notation.

  • Use the CopyTo method to copy the contents of the collection to a System.Array object, which can then be used to get items from the collection.

  • Use the GetEnumerator method to create a System.Collections.IEnumerator implemented object, which can then be used to get items from the collection.

Constructors

Name Description
DataKeyCollection(ArrayList)

Initializes a new instance of the DataKeyCollection class.

Properties

Name Description
Count

Gets the number of items in the collection.
IsReadOnly

Gets a value indicating whether items in the DataKeyCollection can be modified.
IsSynchronized

Gets a value indicating whether the DataKeyCollection is synchronized (thread-safe).
Item[Int32]

Gets the key field at the specified index in the collection.
SyncRoot

Gets the object used to synchronize access to the DataKeyCollection.

Methods

Name Description
CopyTo(Array, Int32)

Copies all the items from the DataKeyCollection to the specified Array object, starting at the specified index in the Array object.
Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetEnumerator()

Creates a IEnumerator implemented object that contains all key fields in the DataKeyCollection.
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString()

Returns a string that represents the current object.

(Inherited from Object)

Extension Methods

Name Description
AsParallel(IEnumerable)

Enables parallelization of a query.
AsQueryable(IEnumerable)

Converts an IEnumerable to an IQueryable.
Cast(IEnumerable)

Casts the elements of an IEnumerable to the specified type.
OfType(IEnumerable)

Filters the elements of an IEnumerable based on a specified type.

Applies to

See also