将snapshot.hasData更改为snapshot.connectionState == ConnectionState.done解决了问题 ...
Future.wait方法接收一个Future对象的列表,并返回一个新的Future对象,该新的Future对象在所有传入的Futures都完成后才会完成。 代码语言:txt 复制 Future<String> future1 = fetchData(); Future<int> future2 = fetchAnotherData(); Future.wait([future1, future2]).then((results) { String result1 = resul...
Streams. Streams enable asynchronous programming and make it easy to work with data that arrives over time. Futures.: Futures represent asynchronous computations that will complete at some point in the future. Dart is a client-optimized language which means that it has been designed specifically...
Framework使用dart语言实现,包括UI,文本,图片,按钮等Widgets,渲染,动画,手势等。此部分的核心代码是flutter仓库下的flutter package,以及sky_engine仓库下的 io, async, ui(dart:ui库提供了Flutter框架和引擎之间的接口)等package。 Engine使用C++实现,主要包括:Skia, Dart 和 Text。 Skia是开源的二维图形库,提供了适...
Im not sure about this, but in my understanding, a FutureBuilder expects exactly 1 future. the returned value of this future is accessable with "snapshot.data". If you need to wait for multiple futures to resolve, I propose you use multiple FutureBuilders. Another way would be to use Futu...
Today we're gonna look out how to work with Future Builder and show the result in GridView. We'll also see how to use Pagination with Future Builder.Future Builder is a widget that returns another widget based on futures execution result. It builds itsel
Flutter comes with multiple performance optimization tools. These tools enable Flutter app developers to examine and boost the performance of a Flutter application. For instance, the Flutter DevTools allows you to analyze and visualize the performance of your app based on metrics like CPU utilization,...
FutureProvider Async values - Yes Yes StreamProvider Streams - Yes Yes StateProvider Simple states setState No No ChangeNotifierProvider More rebuild control Custom methods No No NotifierProvider Regular services Custom methods No No AsyncNotifierProvider Services with futures Custom methods No No Red...
2、关于 Futures 的一些用法 对于await 返回的对象,我们一般用 Future包裹一下。拿到后,既可以直接使用。例如: dart 复制代码var weatherData = await getCityWeather(typedName); 上面http接口,返回的是一个json对象,json对象返回类型 Future, 这是一个可用json对象。假设返回body的json串是: json复制代码{ "coord...
Futures can't pass many values, they will execute and return one value and then they are done. If you need to pass multiple values, you should use a Stream instead. First your Stream emits the value in the cache, then later your Stream emits the value you got from your API. After yo...