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API > @angular/core

IterableChanges

本对象描述自上次调用 IterableDiffer#diff() 以来 Iterable 集合中的变更。

An object describing the changes in the Iterable collection since last time IterableDiffer#diff() was invoked.

      
      interface IterableChanges<V> {
  forEachItem(fn: (record: IterableChangeRecord<V>) => void): void
  forEachOperation(fn: (record: IterableChangeRecord<V>, previousIndex: number, currentIndex: number) => void): void
  forEachPreviousItem(fn: (record: IterableChangeRecord<V>) => void): void
  forEachAddedItem(fn: (record: IterableChangeRecord<V>) => void): void
  forEachMovedItem(fn: (record: IterableChangeRecord<V>) => void): void
  forEachRemovedItem(fn: (record: IterableChangeRecord<V>) => void): void
  forEachIdentityChange(fn: (record: IterableChangeRecord<V>) => void): void
}

实现类

方法

forEachItem()

遍历所有更改。IterableChangeRecord 将包含有关每个条目更改的信息。

Iterate over all changes. IterableChangeRecord will contain information about changes to each item.

      
      forEachItem(fn: (record: IterableChangeRecord<V>) => void): void
参数
fn (record: IterableChangeRecord) => void
返回值

void

forEachOperation()

遍历一组操作，将这些操作应用于原始 Iterable，将产生新的 Iterable 。

Iterate over a set of operations which when applied to the original Iterable will produce the new Iterable.

      
      forEachOperation(fn: (record: IterableChangeRecord<V>, previousIndex: number, currentIndex: number) => void): void
参数
fn (record: IterableChangeRecord, previousIndex: number, currentIndex: number) => void
返回值

void

注意：这些不一定是应用于原始 Iterable 的实际操作，而是这些计算的操作集合，可能与所应用的操作不同。

NOTE: These are not necessarily the actual operations which were applied to the original Iterable, rather these are a set of computed operations which may not be the same as the ones applied.

forEachPreviousItem()

按原始 Iterable 中的顺序遍历这些变更，以找出原始条目移动到的位置。

Iterate over changes in the order of original Iterable showing where the original items have moved.

      
      forEachPreviousItem(fn: (record: IterableChangeRecord<V>) => void): void
参数
fn (record: IterableChangeRecord) => void
返回值

void

forEachAddedItem()

遍历所有添加的条目。

Iterate over all added items.

      
      forEachAddedItem(fn: (record: IterableChangeRecord<V>) => void): void
参数
fn (record: IterableChangeRecord) => void
返回值

void

forEachMovedItem()

遍历所有移动过的条目。

Iterate over all moved items.

      
      forEachMovedItem(fn: (record: IterableChangeRecord<V>) => void): void
参数
fn (record: IterableChangeRecord) => void
返回值

void

forEachRemovedItem()

遍历所有已删除的条目。

Iterate over all removed items.

      
      forEachRemovedItem(fn: (record: IterableChangeRecord<V>) => void): void
参数
fn (record: IterableChangeRecord) => void
返回值

void

forEachIdentityChange()

遍历所有更改过标识（由 TrackByFunction 计算）的条目。

Iterate over all items which had their identity (as computed by the TrackByFunction) changed.

      
      forEachIdentityChange(fn: (record: IterableChangeRecord<V>) => void): void
参数
fn (record: IterableChangeRecord) => void
返回值

void