WebJun 26, 2014 · When you need to wait for multiple Futures to complete and you don't care about the order, you can use Future.wait (): Future.wait (files.map (functionThatReturnsAFuture)) .then ( (List response) => print ('All files processed')); If order is important you can use Future.forEach () instead which waits for each Future to be … WebDec 20, 2024 · When to use then? When you want to process Future after it was successfully finished in an async way - program will continue execution after this async …
dart - What is the purpose of `FutureOr`? - Stack Overflow
WebOct 24, 2024 · A Dart async/await and Future/then example Flutter tip: When you want to make initState or build an async method, think FutureBuilder Flutter error: Unhandled Exception: MissingPluginException(No implementation found for method canLaunch on channel plugins... WebMar 7, 2010 · Future < R > then < R >(. FutureOr < R > onValue (. T value {Function? onError}Register callbacks to be called when this future completes. When this future completes with a value, the onValue callback will be called with that value. If this future is already completed, the callback will not be called immediately, but will be scheduled in a … simple drawings of crosses
then method - Future class - dart:async library - Dart API
WebFeb 14, 2024 · Fetching data from APIs on remote servers is one of the most common use cases of Future, async, and await in Flutter. For convenience, you should install the http package, a Future-based library … Lets take an example where you have a screen where you can tap to download various items out of a list. You want wait for all these futures to be complete before you continue with your code. Future has a handy .wait call. This call allows you to provide a list of Futures to it and it will run all of them and when … See more A future is defined exactly like a function in dart, but instead of void you use Future. If you want to return a value from the Future then you pass it a type. See more There are two ways to execute a Future and use the value it returns. If it returns any. The most common way is to await on the Future to return. For this to work your function that’s calling … See more Sometimes we don’t know exactly how long a future will run. It is a process that the user has to explicitly wait for .i.e. there’s a loading indicator on the screen then you probably don’t want it to run for too long. In case you … See more Futures has its own way of handling errors. In the .then call, in addition to passing in your callback you can also pass in a function to … See more WebJan 27, 2024 · Key to running multiple futures in parallel. The biggest key to the solution is this code: Future.wait ( [async1 (), async2 (), async3 ()]) .then ( (List nums) {. That code runs the functions async1, async2, and async3 in parallel, and then makes the nums list available when all three futures have completed. simple drawings of eagles