DataKeyCollection Class

 

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

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

System::Object
  System.Web.UI.WebControls::DataKeyCollection

public ref class DataKeyCollection sealed : ICollection, IEnumerable

NameDescription
System_CAPS_pubmethodDataKeyCollection(ArrayList^)

Initializes a new instance of the DataKeyCollection class.

NameDescription
System_CAPS_pubpropertyCount

Gets the number of items in the collection.

System_CAPS_pubpropertyIsReadOnly

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

System_CAPS_pubpropertyIsSynchronized

Gets a value indicating whether the DataKeyCollection is synchronized (thread-safe).

System_CAPS_pubpropertyItem[Int32]

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

System_CAPS_pubpropertySyncRoot

Gets the object used to synchronize access to the DataKeyCollection.

NameDescription
System_CAPS_pubmethodCopyTo(Array^, Int32)

Copies all the items from the DataKeyCollection to the specified System::Array object, starting at the specified index in the System::Array object.

System_CAPS_pubmethodEquals(Object^)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetEnumerator()

Creates a System.Collections::IEnumerator implemented object that contains all key fields in the DataKeyCollection.

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubmethodAsParallel()

Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)

System_CAPS_pubmethodAsQueryable()

Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)

System_CAPS_pubmethodCast<TResult>()

Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)

System_CAPS_pubmethodOfType<TResult>()

Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

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.

No code example is currently available or this language may not be supported.

.NET Framework
Available since 1.1

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

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