IViewCursor - Adobe ActionScript® 3 (AS3 Flex) API 參考

套件	mx.collections
介面	public interface IViewCursor extends IEventDispatcher

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Defines the interface for enumerating a collection view bi-directionally. This cursor provides find, seek, and bookmarking capabilities along with the modification methods insert and remove. When a cursor is first retrieved from a view, (typically by the ICollectionView createCursor() method) the value of the current property should be the first item in the view, unless the view is empty.

公用屬性

	屬性		定義自
		afterLast : Boolean [唯讀] If the cursor is located after the last item in the view, this property is true .	IViewCursor
		beforeFirst : Boolean [唯讀] If the cursor is located before the first item in the view, this property is true.	IViewCursor
		bookmark : CursorBookmark [唯讀] Provides access to a bookmark that corresponds to the item returned by the current property.	IViewCursor
		current : Object [唯讀] Provides access the object at the location in the source collection referenced by this cursor.	IViewCursor
		view : ICollectionView [唯讀] A reference to the ICollectionView with which this cursor is associated.	IViewCursor

公用方法

隱藏繼承公用方法

顯示繼承公用方法

	方法		定義自
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void 會在 EventDispatcher 物件註冊事件偵聽程式，以便讓偵聽程式收到事件的通知。	IEventDispatcher
		dispatchEvent(event:Event):Boolean 會將事件傳送到事件流程。	IEventDispatcher
		findAny(values:Object):Boolean Finds an item with the specified properties within the collection and positions the cursor to that item.	IViewCursor
		findFirst(values:Object):Boolean Finds the first item with the specified properties within the collection and positions the cursor to that item.	IViewCursor
		findLast(values:Object):Boolean Finds the last item with the specified properties within the collection and positions the cursor on that item.	IViewCursor
		hasEventListener(type:String):Boolean 會檢查 EventDispatcher 物件是否有對特定的事件類型註冊偵聽程式。	IEventDispatcher
		insert(item:Object):void Inserts the specified item before the cursor's current position.	IViewCursor
		moveNext():Boolean Moves the cursor to the next item within the collection.	IViewCursor
		movePrevious():Boolean Moves the cursor to the previous item within the collection.	IViewCursor
		remove():Object Removes the current item and returns it.	IViewCursor
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void 會從 EventDispatcher 物件移除偵聽程式。	IEventDispatcher
		seek(bookmark:CursorBookmark, offset:int = 0, prefetch:int = 0):void Moves the cursor to a location at an offset from the specified bookmark.	IViewCursor
		willTrigger(type:String):Boolean 檢查此 EventDispatcher 物件是否已註冊事件偵聽程式，或者此物件的任何祖系已為特定事件類型註冊事件偵聽程式。	IEventDispatcher

事件

按一下以瞭解事件的詳細資訊

	事件		摘要	定義自
		cursorUpdate	Dispatched whenever the cursor position is updated.	IViewCursor

屬性詳細資訊

afterLast

屬性

afterLast:Boolean [唯讀]

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

If the cursor is located after the last item in the view, this property is true . If the ICollectionView is empty (length == 0), this property is true.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 cursorUpdate 事件。

實作
public function get afterLast():Boolean

beforeFirst

屬性

beforeFirst:Boolean [唯讀]

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

If the cursor is located before the first item in the view, this property is true. If the ICollectionView is empty (length == 0), this property is true.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 cursorUpdate 事件。

實作
public function get beforeFirst():Boolean

bookmark

屬性

bookmark:CursorBookmark [唯讀]

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Provides access to a bookmark that corresponds to the item returned by the current property. The bookmark can be used to move the cursor to a previously visited item, or to a position relative to that item. (See the seek() method for more information.)

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 cursorUpdate 事件。

實作
public function get bookmark():CursorBookmark

相關 API 元素

current
seek()

current

屬性

current:Object [唯讀]

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Provides access the object at the location in the source collection referenced by this cursor. If the cursor is beyond the ends of the collection (beforeFirst, afterLast) this will return null.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 cursorUpdate 事件。

實作
public function get current():Object

view

屬性

view:ICollectionView [唯讀]

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

A reference to the ICollectionView with which this cursor is associated.

實作
public function get view():ICollectionView

方法詳細資訊

findAny

()

方法

public function findAny(values:Object):Boolean

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Finds an item with the specified properties within the collection and positions the cursor to that item. If the item can not be found, the cursor location does not change.

The findAny() method can only be called on sorted views; if the view isn't sorted, a CursorError is thrown.

If the associated collection is remote, and not all of the items have been cached locally, this method begins an asynchronous fetch from the remote collection. If one is already in progress, this method waits for it to complete before making another fetch request.

If multiple items can match the search criteria then the item found is non-deterministic. If it is important to find the first or last occurrence of an item in a non-unique index, use the findFirst() or findLast() method.

If the data is not local and an asynchronous operation must be performed, an ItemPendingError is thrown.

參數

values:Object — The search criteria. The values in the Object must be configured as name-value pairs, as in an associative array (or be the actual object to search for). The values of the names specified must match properties specified in the sort. For example, if properties x, y, and z are in the current sort, the values specified should be {x: x-value, y: y-value, z: z-value}.

傳回值

Boolean — When all of the data is local this method returns true if the item can be found and false otherwise.

findFirst

()

方法

public function findFirst(values:Object):Boolean

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Finds the first item with the specified properties within the collection and positions the cursor to that item. If the item can not be found, no cursor location does not change.

The findFirst() method can only be called on sorted views; if the view isn't sorted, a CursorError is thrown.

If it is not important to find the first occurrence of an item in a non-unique index, use findAny(), which may be a little faster than the findFirst() method.

If the data is not local and an asynchronous operation must be performed, an ItemPendingError is thrown.

參數

傳回值

Boolean — When all of the data is local this method returns true if the item can be found and false otherwise.

findLast

()

方法

public function findLast(values:Object):Boolean

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Finds the last item with the specified properties within the collection and positions the cursor on that item. If the item can not be found, the cursor location does not chanage.

The findLast() method can only be called on sorted views; if the view isn't sorted, a CursorError is thrown.

If it is not important to find the last occurrence of an item in a non-unique index, use the findAny() method, which may be a little faster.

If the data is not local and an asynchronous operation must be performed, an ItemPendingError is thrown.

參數

傳回值

Boolean — When all of the data is local this method returns true if the item can be found and false otherwise.

insert

()

方法

public function insert(item:Object):void

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Inserts the specified item before the cursor's current position. If the cursor is afterLast, the insertion occurs at the end of the view. If the cursor is beforeFirst on a non-empty view, an error is thrown.

參數

item:Object — The item to insert before the cursor's current position.

moveNext

()

方法

public function moveNext():Boolean

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Moves the cursor to the next item within the collection. On success the current property is updated to reference the object at this new location. Returns true if the resulting current property is valid, or false if not (the property value is afterLast).

If the data is not local and an asynchronous operation must be performed, an ItemPendingError is thrown. See the ItemPendingError documentation and the collections documentation for more information on using the ItemPendingError.

傳回值

Boolean — true if still in the list, false if the current value initially was or now is afterLast.

範例
如何使用本範例

      var myArrayCollection:ICollectionView = new ArrayCollection([ "Bobby", "Mark", "Trevor", "Jacey", "Tyler" ]);
      var cursor:IViewCursor = myArrayCollection.createCursor();
      while (!cursor.afterLast)
      {
          trace(cursor.current);
          cursor.moveNext();
      }

movePrevious

()

方法

public function movePrevious():Boolean

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Moves the cursor to the previous item within the collection. On success the current property is updated to reference the object at this new location. Returns true if the resulting current property is valid, or false if not (the property value is beforeFirst).

傳回值

Boolean — true if still in the list, false if the current value initially was or now is beforeFirst. For example:

      var myArrayCollection:ICollectionView = new ArrayCollection([ "Bobby", "Mark", "Trevor", "Jacey", "Tyler" ]);
      var cursor:IViewCursor = myArrayCollection.createCursor();
      cursor.seek(CursorBookmark.last);
      while (!cursor.beforeFirst)
      {
          trace(current);
          cursor.movePrevious();
      }

remove

()

方法

public function remove():Object

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Removes the current item and returns it. If the cursor location is beforeFirst or afterLast, throws a CursorError. If you remove any item other than the last item, the cursor moves to the next item. If you remove the last item, the cursor is at the AFTER_LAST bookmark.

If the item after the removed item is not local and an asynchronous operation must be performed, an ItemPendingError is thrown. See the ItemPendingError documentation and the collections documentation for more information on using the ItemPendingError.

傳回值

Object — The item that was removed.

相關 API 元素

mx.collections.errors.ItemPendingError

seek

()

方法

public function seek(bookmark:CursorBookmark, offset:int = 0, prefetch:int = 0):void

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Moves the cursor to a location at an offset from the specified bookmark. The offset can be negative, in which case the cursor is positioned an offset number of items prior to the specified bookmark.

If the associated collection is remote, and not all of the items have been cached locally, this method begins an asynchronous fetch from the remote collection.

參數

	`bookmark:CursorBookmark` — `CursorBookmark` reference to marker information that allows repositioning to a specific location. You can set this parameter to value returned from the `bookmark` property, or to one of the following constant bookmark values: `CursorBookmark.FIRST` - Seek from the start (first element) of the collection `CursorBookmark.CURRENT` - Seek from the current position in the collection `CursorBookmark.LAST` - Seek from the end (last element) of the collection

	`offset:int` (default = `0`) — Indicates how far from the specified bookmark to seek. If the specified number is negative, the cursor attempts to move prior to the specified bookmark. If the offset specified is beyond the end of the collection, the cursor is be positioned off the end, to the `beforeFirst` or `afterLast` location.

	`prefetch:int` (default = `0`) — Used for remote data. Indicates an intent to iterate in a specific direction once the seek operation completes. This reduces the number of required network round trips during a seek. If the iteration direction is known at the time of the request, the appropriate amount of data can be returned ahead of the request to iterate it.

相關 API 元素

mx.collections.errors.ItemPendingError

事件詳細資訊

cursorUpdate

事件

事件物件類型: mx.events.FlexEvent
屬性 FlexEvent.type = mx.events.FlexEvent.CURSOR_UPDATE

語言版本:

ActionScript 3.0

產品版本:

Flex 3

執行階段版本:

Flash Player 9, AIR 1.1

Dispatched whenever the cursor position is updated.

The FlexEvent.CURSOR_UPDATE constant defines the value of the type property of the event object for a cursorUpdate event.

The properties of the event object have the following values:

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`.
`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.

法律聲明 | 線上隱私權政策

IViewCursor - AS3 Flex

類別 x

afterLast

beforeFirst

bookmark

current

view

findAny

findFirst

findLast

insert

moveNext

movePrevious

remove

seek

cursorUpdate