flutter - 没有 RxDart 的 StreamController 的初始值

Question

我在 Flutter 中使用 StreamControllers。我有一个带有一些默认值的模型。从我正在收听流的小部件中，我想提供其中一些默认值。我可以看到我可以在 StreamBuilder 上设置一个初始值，但我想使用来自 bloc 内部模型的数据作为初始数据。因此，一旦有人使用快照数据，他们就会获得默认值。我已经看到 RxDart 有一个种子值，只是想知道这是否可能而不用 RxDart 替换？

Answer 1

您要找的是StreamController#add方法，

Sends a data event.

Listeners receive this event in a later microtask.

Note that a synchronous controller (created by passing true to thesync parameter of the StreamController constructor) delivers eventsimmediately. Since this behavior violates the contract mentioned here,synchronous controllers should only be used as described in thedocumentation to ensure that the delivered events always appear as ifthey were delivered in a separate microtask.

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