Flutter StreamBuilder与FutureBuilder [英] Flutter StreamBuilder vs FutureBuilder

问题描述

StreamBuilder 和 FutureBuilder 的主要区别是什么。

• 使用什么以及何时使用？




• 他们打算执行什么任务？




• 每个人如何侦听动态列表中的更改？

解决方案

StreamBuilder 和 FutureBuilder 具有相同的行为：他们监听各自对象上的更改。并在通知他们
新值时触发新的构建。

因此，最终，他们的区别在于他们侦听对象的方式。 / p>

未来类似于JS或<$ c中的 Promise c＃中的$ c>任务。它们是异步请求的表示。 未来只有一个响应。 Future 的常见用法是处理http调用。您可以在未来上聆听它的状态。无论是完成，成功完成还是出错。

流就像异步 Iterator 在JS中。可以将其同化为随时间变化的值。它通常是Web套接字或事件（例如点击）的表示。通过收听 Stream ，您将获得每个新值，以及 Stream 是否有错误或已完成。 / p>

他们每个人如何侦听动态列表中的更改？

A 未来无法收听变量更改。这是一次回应。相反，您需要使用流。

What is the main difference between StreamBuilder and FutureBuilder.

• What to use and when to use?

• What are the tasks they are intended to perform?

• How each of them listens to changes in a dynamic list?

解决方案

Both StreamBuilder and FutureBuilder have the same behavior : They listen to changes on their respective object. And trigger a new build when they are notified of a new value.

So in the end, their differences is how the object they listen to works.

Future are like Promise in JS or Task in c#. They are the representation of an asynchronous request. Futures have one and only one response. A common usage of Future is to handle http calls. What you can listen on a Future is it's state. Whether it's done, finished with a success, or had an error. But that's it.

Stream on the other hand are like async Iterator in JS. This can be assimilated to a value that can change over time. It usually is the representation of web-sockets or events (such as click). By listening to a Stream you'll get each new value and also if the Stream had an error or completed.

How each of them listens to changes in a dynamic list?

A Future can't listen to a variable change. It's a one time response. Instead you'll need to use a Stream.

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