AsyncListView

Paket	mx.collections
Sınıf	public class AsyncListView
Miras Alma	AsyncListView OnDemandEventDispatcher Object
Uygular	IList

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

The AsyncListView class is an implementation of the IList interface that handles ItemPendingErrors errors thrown by the getItemAt(), removeItemAt(), and toArray() methods.

The getItemAt() method handles ItemPendingErrors by returning a provisional "pending" item until the underlying request succeeds or fails. The provisional item is produced by calling the function specified by the createPendingItemFunction property. . If the request succeeds, the actual item replaces the provisional one. If it fails, the provisional item is replaced with the item returned by calling the function specified by the createFailedItemFunction property.

This class delegates the IList methods and properties to its list. If a list isn't specified, methods that mutate the collection are no-ops, and methods that query the collection return an empty value, such as null or zero as appropriate.

This class is intended to be used with Spark components based on DataGroup, such as List and ComboBox. The Spark classes do not provide intrinsic support for ItemPendingError handling.

AsyncListView does not support re-insertion of pending or failed items. Once a failed or pending item is removed, its connection to a pending request for data is lost. Using drag and drop to move a pending item in an ASyncListView, or sorting an ASyncListView that contains pending or failed items, is not supported because these operations remove and then re-insert list items.

MXML Sözdizimi expanded

MXML Sözdizimini Gizle

The <mx:AsyncListView> tag inherits all the attributes of its superclass, and adds the following attributes:

  <mx:AsyncListView
  Properties
    createFailedItemFunction="null"
    createPendingItemFunction="null"
    list="null"
  />

Genel Özellikler

Miras Alınan Genel Özellikleri Gizle

Miras Alınan Genel Özellikleri Göster

	Özellik		Tanımlayan:
		constructor : Object Belirli bir nesne örneği için sınıf nesnesine veya yapıcı işlevine bir başvuru.	Object
		createFailedItemFunction : Function A callback function used to create a substitute item when a request which had caused an ItemPendingError to be thrown, subsequently fails.	AsyncListView
		createPendingItemFunction : Function A callback function used to create a provisional item when the initial request causes an ItemPendingError to be thrown.	AsyncListView
		length : int [salt okunur] The number of items in this collection.	AsyncListView
		list : IList The IList object that this collection wraps.	AsyncListView

Genel Yöntemler

Miras Alınan Genel Yöntemleri Gizle

Miras Alınan Genel Yöntemleri Göster

	Yöntem		Tanımlayan:
		AsyncListView(list:IList = null) Constructor.	AsyncListView
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.	OnDemandEventDispatcher
		addItem(item:Object):void Adds the specified item to the end of the list.	AsyncListView
		addItemAt(item:Object, index:int):void Adds the item at the specified index.	AsyncListView
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	OnDemandEventDispatcher
		getItemAt(index:int, prefetch:int = 0):Object Returns the value of list.getItemAt(index).	AsyncListView
		getItemIndex(item:Object):int Returns the index of the item if it is in the list such that getItemAt(index) == item.	AsyncListView
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	OnDemandEventDispatcher
		hasOwnProperty(name:String):Boolean Bir nesnenin belirli bir özelliğinin tanımlı olup olmadığını gösterir.	Object
		isPrototypeOf(theClass:Object):Boolean Object sınıfının bir örneğinin parametre olarak belirtilen nesnenin prototip zincirinde olup olmadığını gösterir.	Object
		itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void Notifies the view that an item has been updated.	AsyncListView
		propertyIsEnumerable(name:String):Boolean Belirtilen özelliğin bulunup bulunmadığını ve numaralandırılabilir olup olmadığını gösterir.	Object
		removeAll():void Removes all items from the list.	AsyncListView
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	OnDemandEventDispatcher
		removeItemAt(index:int):Object Removes the actual or pending item at the specified index and returns it.	AsyncListView
		setItemAt(item:Object, index:int):Object Places the item at the specified index.	AsyncListView
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Dinamik bir özelliğin döngü işlemlerinde kullanılabilirliğini ayarlar.	Object
		toArray():Array Returns an array with the same elements as this AsyncListView.	AsyncListView
		toLocaleString():String Bu nesnenin, yerel ayara özel kurallara göre biçimlendirilmiş dize temsilini döndürür.	Object
		toString():String Returns a string that contains the list's length and the number of pending item requests.	AsyncListView
		valueOf():Object Belirtilen nesnenin temel değerini döndürür.	Object
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	OnDemandEventDispatcher

Olaylar

Olaylarla ilgili daha fazla bilgi için tıklatın

	Olay		Özet	Tanımlayan:
		collectionChange	Dispatched when the list's length has changed or when a list element is replaced.	AsyncListView

Özellik Ayrıntısı

createFailedItemFunction

özellik

createFailedItemFunction:Function

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

A callback function used to create a substitute item when a request which had caused an ItemPendingError to be thrown, subsequently fails. The existing item, typically a pending item created by the callback function specified by the createPendingItemFunction() property, is replaced with the failed item.

The value of this property must be a function with two parameters: the index of the requested item, and the failure "info" object, which is passed along from the IResponder fault() method. In most cases you can ignore the second parameter. Shown below is an example implementation of the callback function:

     function createFailedItem(index:int, info:Object):Object
     {
         return "[" + index + "request failed]";        
     }

Setting this property does not affect failed items that were already created. Setting this property to null prevents failed items from being created.

Varsayılan değer şudur A function that unconditionally returns null..

Uygulama
public function get createFailedItemFunction():Function
public function set createFailedItemFunction(value:Function):void

İlgili API Öğeleri

getItemAt()
createPendingItemFunction
mx.rpc.IResponder.fault

createPendingItemFunction

özellik

createPendingItemFunction:Function

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

A callback function used to create a provisional item when the initial request causes an ItemPendingError to be thrown. If the request eventually succeeds, the provisional item is automatically replaced by the actual item. If the request fails, then the item is replaced with one created with the callback function specified by the createFailedItemFunction property.

The value of this property must be a function with two parameters: the index of the requested data provider item, and the ItemPendingError itself. In most cases, the second parameter can be ignored. The following example shows an implementation of the callback function:

     function createPendingItem(index:int, ipe:ItemPendingError):Object
     {
         return "[" + index + "request is pending...]";        
     }

Setting this property does not affect provisional pending items that were already created. Setting this property to null prevents provisional pending items from being created.

Varsayılan değer şudur A function that unconditionally returns null..

Uygulama
public function get createPendingItemFunction():Function
public function set createPendingItemFunction(value:Function):void

İlgili API Öğeleri

getItemAt()
createFailedItemFunction
mx.collections.errors.ItemPendingError

length

özellik

length:int [salt okunur]

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

The number of items in this collection. 0 means no items while -1 means the length is unknown.

Bu özellik veri ciltleme kaynağı olarak kullanılabilir. Bu özellik değiştirildiğinde, collectionChange olayını gönderir.

Uygulama
public function get length():int

list

özellik

list:IList

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

The IList object that this collection wraps. That means the object to which all of the IList methods are delegated.

If this property is null, the IList mutation methods, such as setItemAt(), are no-ops. The IList query methods, such getItemAt(), return null or zero (-1 for getItemIndex()), as appropriate.

Varsayılan değer şudur null.

Bu özellik veri ciltleme kaynağı olarak kullanılabilir. Bu özellik değiştirildiğinde, listChanged olayını gönderir.

Uygulama
public function get list():IList
public function set list(value:IList):void

Yapıcı Ayrıntı

()

Yapıcı

public function AsyncListView(list:IList = null)

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Constructor.

Parametreler

list:IList (default = null) — Initial value of the list property, the IList we're delegating to.

Yöntem Ayrıntısı

addItem

()

yöntem

public function addItem(item:Object):void

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Adds the specified item to the end of the list. Equivalent to addItemAt(item, length).

Parametreler

item:Object — The item to add.

addItemAt

()

yöntem

public function addItemAt(item:Object, index:int):void

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Adds the item at the specified index. The index of any item greater than the index of the added item is increased by one. If the the specified index is less than zero or greater than the length of the list, a RangeError is thrown.

Parametreler

	`item:Object` — The item to place at the index.

	`index:int` — The index at which to place the item.

getItemAt

()

yöntem

public function getItemAt(index:int, prefetch:int = 0):Object

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Returns the value of list.getItemAt(index).

This method catches ItemPendingErrors (IPEs) generated as a consequence of calling getItemAt(). If an IPE is thrown, an IResponder is added to the IPE and a provisional "pending" item, created with the createPendingItemFunction is returned. If the underlying request eventually succeeds, the pending item is replaced with the real item. If it fails, the pending item is replaced with a value produced by calling createFailedItemFunction.

Parametreler

	`index:int` — The list index from which to retrieve the item.

	`prefetch:int` (default = `0`) — An `int` indicating both the direction and number of items to fetch during the request if the item is not local.

Döndürür

Object — The list item at the specified index.

Atar

RangeError — if index < 0 or index >= length.

İlgili API Öğeleri

createPendingItemFunction
createFailedItemFunction
mx.collections.errors.ItemPendingError
mx.rpc.IResponder

getItemIndex

()

yöntem

public function getItemIndex(item:Object):int

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Returns the index of the item if it is in the list such that getItemAt(index) == item.

Note: unlike IViewCursor.findxxx() methods, The getItemIndex() method cannot take a parameter with only a subset of the fields in the item being serched for; this method always searches for an item that exactly matches the input parameter.

Parametreler

item:Object — The item to find.

Döndürür

int — The index of the item, or -1 if the item is not in the list.

itemUpdated

()

yöntem

public function itemUpdated(item:Object, property:Object = null, oldValue:Object = null, newValue:Object = null):void

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Notifies the view that an item has been updated. This is useful if the contents of the view do not implement IEventDispatcher and dispatches a PropertyChangeEvent. If a property is specified the view may be able to optimize its notification mechanism. Otherwise it may choose to simply refresh the whole view.

Parametreler

	`item:Object` — The item within the view that was updated.

	`property:Object` (default = `null`) — The name of the property that was updated.

	`oldValue:Object` (default = `null`) — The old value of that property. (If property was null, this can be the old value of the item.)

	`newValue:Object` (default = `null`) — The new value of that property. (If property was null, there's no need to specify this as the item is assumed to be the new value.)

removeAll

()

yöntem

public function removeAll():void

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Removes all items from the list.

If any item is not local and an asynchronous operation must be performed, an ItemPendingError will be thrown.

See the ItemPendingError documentation as well as the collections documentation for more information on using the ItemPendingError.

removeItemAt

()

yöntem

public function removeItemAt(index:int):Object

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Removes the actual or pending item at the specified index and returns it. All items whose index is greater than the specified index have their index reduced by 1.

If there is no actual or pending item at the specified index, for example because a call to getItemAt(index) hasn't caused the data to be paged in, then the underlying list may throw an ItemPendingError. The implementation ignores the ItemPendingError and returns null.

Parametreler

index:int — The list index from which to retrieve the item.

Döndürür

Object — The item that was removed or null.

Atar

RangeError — if index < 0 or index >= length.

setItemAt

()

yöntem

public function setItemAt(item:Object, index:int):Object

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Places the item at the specified index. If an item was already at that index the new item will replace it and it will be returned.

Parametreler

	`item:Object` — The new item to be placed at the specified index.

	`index:int` — The index at which to place the item.

Döndürür

Object — The item that was replaced, or null if none.

toArray

()

yöntem

public function toArray():Array

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Returns an array with the same elements as this AsyncListView. The array is initialized by retrieving each item with getItemAt(), so pending items are substituted where actual values aren't available yet. The array will not be updated when the AsyncListView replaces the pending items with actual (or failed) values.

Döndürür

Array — an array with the same elements as this AsyncListView.

toString

()

yöntem

public function toString():String

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 4

Çalışma Zamanı Sürümleri:

Flash Player 10, AIR 1.5

Returns a string that contains the list's length and the number of pending item requests. It does not trigger pending requests.

Döndürür

String — A brief description of the list.

Olay Ayrıntısı

collectionChange

Olay

Olay Nesne Türü: mx.events.CollectionEvent
özellik CollectionEvent.type = mx.events.CollectionEvent.COLLECTION_CHANGE

Dil Sürümü:

ActionScript 3.0

Ürün Sürümü:

Flex 3

Çalışma Zamanı Sürümleri:

Flash Player 9, AIR 1.1

Dispatched when the list's length has changed or when a list element is replaced.

The CollectionEvent.COLLECTION_CHANGE constant defines the value of the type property of the event object for an event that is dispatched when a collection has changed.

The properties of the event object have the following values. Not all properties are meaningful for all kinds of events. See the detailed property descriptions for more information.

Property	Value
`bubbles`	false
`cancelable`	false
`currentTarget`	The Object that defines the event listener that handles the event. For example, if you use `myButton.addEventListener()` to register an event listener, myButton is the value of the `currentTarget`.
`items`	An Array of objects with information about the items affected by the event. The contents of this field depend on the event kind; for details see the `items` property
`kind`	The kind of event. The valid values are defined in the CollectionEventKind class as constants.
`location`	Location within the target collection of the item(s) specified in the `items` property.
`oldLocation`	the previous location in the collection of the item specified in the `items` property.
`target`	The Object that dispatched the event; it is not always the Object listening for the event. Use the `currentTarget` property to always access the Object listening for the event.
`type`	CollectionEvent.COLLECTION_CHANGE

Yasal Uyarılar | Çevrimiçi Gizlilik İlkesi

AsyncListView - AS3 Flex

Sınıflar x

createFailedItemFunction

createPendingItemFunction

length

list

AsyncListView

addItem

addItemAt

getItemAt

getItemIndex

itemUpdated

removeAll

removeItemAt

setItemAt

toArray

toString

collectionChange