滚动 Scrolling

返回一个可观察对象，它只在元素的任何可滚动祖先发生滚动时才会触发。

Returns an observable that emits whenever any of the scrollable ancestors of an element are scrolled.

注销一个可滚动对象的引用，并从它的 scroll 事件的可观察对象中取消订阅。

Deregisters a Scrollable reference and unsubscribes from its scroll event observable.

返回所有包含所指定元素的已注册可滚动对象。

Returns all registered Scrollables that contain the provided element.

使用该服务注册一个可滚动的实例，并侦听其滚动的事件。当可滚动对象发生滚动时，此服务会把事件发送到记录其滚动的可观察对象中。

Registers a scrollable instance with the service and listens for its scrolled events. When the scrollable is scrolled, the service emits the event to its scrolled observable.

返回一个可观察对象，它会在任何已注册的可滚动对象引用（或 window, document, body）中发生滚动事件时发出一个事件。可以提供一个毫秒数来来改写默认的“限流”时间。

Returns an observable that emits an event whenever any of the registered Scrollable references (or window, document, or body) fire a scrolled event. Can provide a time in ms to override the default "throttle" time.

注意：为了避免每次滚动事件都发生变更检测，从这个流发出的所有事件都会在 Angular Zone 之外运行。如果你要在滚动事件中更新任何数据绑定，就必须使用 NgZone.run 来运行回调。

Note: in order to avoid hitting change detection for every scroll event, all of the events emitted from this stream will be run outside the Angular zone. If you need to update any data bindings as a result of a scroll event, you have to run the callback using NgZone.run.

返回在宿主元素上发生 scroll 事件时会触发的可观察对象。

Returns observable that emits when a scroll event is fired on the host element.

获取视口的 ElementRef。

Gets the ElementRef for the viewport.

测量相对于视口指定边缘的滚动偏移量。这个方法可以用来代替对 scrollLeft 或 scrollTop 的直接检查，因为各浏览器对于 scrollLeft 在 RTL 中的理解并不一致。 该方法返回的值是标准化的，左右都总是指向滚动容器的左侧和右侧，与布局方向无关。 start 和 end 在 LTR 上下文中指向左右，在 RTL 上下文则相反。

Measures the scroll offset relative to the specified edge of the viewport. This method can be used instead of directly checking scrollLeft or scrollTop, since browsers are not consistent about what scrollLeft means in RTL. The values returned by this method are normalized such that left and right always refer to the left and right side of the scrolling container irrespective of the layout direction. start and end refer to left and right in an LTR context and vice-versa in an RTL context.

滚动到指定的偏移量。这是浏览器原生 scrollTo 方法的标准化版本，因为各个浏览器对于 scrollLeft 在 RTL 中的理解并不一致。 对于此方法，无论布局方向如何，左右都总是指向滚动容器的左侧和右侧。start 和 end 在 LTR 上下文中分别指向左右，在 RTL 上下文中则相反。

Scrolls to the specified offsets. This is a normalized version of the browser's native scrollTo method, since browsers are not consistent about what scrollLeft means in RTL. For this method left and right always refer to the left and right side of the scrolling container irrespective of the layout direction. start and end refer to left and right in an LTR context and vice-versa in an RTL context.

测量指定范围内所有条目的组合大小（水平方向的宽度，垂直方向的高度）。如果该范围包含当前尚未渲染过的条目，则会引发错误。

Measures the combined size (width for horizontal orientation, height for vertical) of all items in the specified range. Throws an error if the range includes items that are not currently rendered.

把 CdkVirtualScrollRepeater 附加到这个视口。

Attaches a CdkVirtualScrollRepeater to this viewport.

更新视口规格并重新渲染。

Update the viewport dimensions and re-render.

拆除当前的 CdkVirtualForOf 。

Detaches the current CdkVirtualForOf.

返回在宿主元素上发生 scroll 事件时会触发的可观察对象。

Returns observable that emits when a scroll event is fired on the host element.

获取绑定到该视口的数据的长度（以条目数表示）。

Gets the length of the data bound to this viewport (in number of items).

获取视口的 ElementRef。

Gets the ElementRef for the viewport.

获取从视口起点到渲染数据起始位置的偏移量（以像素为单位）。

Gets the offset from the start of the viewport to the start of the rendered data (in pixels).

获取当前渲染的条目范围。

Get the current rendered range of items.

获取视口的大小（以像素为单位）。

Gets the size of the viewport (in pixels).

测量指定范围的总组合大小。如果该范围包含未渲染的条目，则抛出此异常。

Measure the total combined size of the given range. Throws if the range includes items that are not rendered.

测量所有渲染条目的组合大小。

Measure the combined size of all of the rendered items.

从视口的开头得到当前的滚动偏移量（以像素为单位）。

Gets the current scroll offset from the start of the viewport (in pixels).

滚动到指定的偏移量。这是浏览器原生 scrollTo 方法的标准化版本，因为各个浏览器对于 scrollLeft 在 RTL 中的理解并不一致。 对于此方法，无论布局方向如何，左右都总是指向滚动容器的左侧和右侧。start 和 end 在 LTR 上下文中分别指向左右，在 RTL 上下文中则相反。

Scrolls to the specified offsets. This is a normalized version of the browser's native scrollTo method, since browsers are not consistent about what scrollLeft means in RTL. For this method left and right always refer to the left and right side of the scrolling container irrespective of the layout direction. start and end refer to left and right in an LTR context and vice-versa in an RTL context.

滚动到指定索引处的偏移量。

Scrolls to the offset for the given index.

从视口开始处滚动到指定的偏移量。请注意，这并不会总是与设置 scrollTop 或 scrollLeft 一致。在水平视口中，视图是从右向左的方向，这相当于设置了一个虚构的 scrollRight 属性。

Scrolls to the given offset from the start of the viewport. Please note that this is not always the same as setting scrollTop or scrollLeft. In a horizontal viewport with right-to-left direction, this would be the equivalent of setting a fictional scrollRight property.

设置从视口起点到渲染数据起点或终点的偏移量（以像素为单位）。

Sets the offset from the start of the viewport to either the start or end of the rendered data (in pixels).

设置当前渲染的索引范围。

Sets the currently rendered range of indices.

设置所有内容的总大小（以像素为单位），包括当前未渲染的内容。

Sets the total size of all content (in pixels), including content that is not currently rendered.

把这个滚动策略附加到视口中。

Attaches this scroll strategy to a viewport.

这个滚动策略是从当前连接的视口中拆除出来的。

Detaches this scroll strategy from the currently attached viewport.

滚动到指定索引的偏移量。

Scroll to the offset for the given index.

更新条目大小和缓冲区大小。

Update the item size and buffer size.

把这个滚动策略附加到视口中。

Attaches this scroll strategy to a viewport.

把这个滚动策略从当前连接的视口中拆除。

Detaches this scroll strategy from the currently attached viewport.

当 DOM 中渲染的条目范围发生变化时调用。

Called when the range of items rendered in the DOM has changed.

在视口发生滚动时调用（使用 requestAnimationFrame 来防抖）。

Called when the viewport is scrolled (debounced using requestAnimationFrame).

当数据长度发生变化时调用。

Called when the length of the data changes.

当渲染条目的偏移量发生变化时调用。

Called when the offset of the rendered items changed.

滚动到指定索引的偏移量。

Scroll to the offset for the given index.