Rx.Observable.prototype.groupBy(keySelector, [elementSelector], [comparer])
Groups the elements of an observable sequence according to a specified key selector function and comparer and selects the resulting elements by using a specified function.
参数
keySelector
(Function
): A function to extract the key for each element.[elementSelector]
(Function
): A function to map each source element to an element in an observable group.[comparer]
(Any
): Used to compare objects. If not specified, the default comparer is used.
返回值
(Observable
): A sequence of observable groups, each of which corresponds to a unique key value, containing all elements that share that same key value.