Future<void> main() async { print('Start'); await firstAsyncTask(); await secondAsyncTask(); print('End'); } Future<void> firstAsyncTask() async { print('First async task start'); await Future.delayed(Duration(seconds: 2)); // 模拟耗时操作 print('First async task end'); } F...
await也可以帮助我们在执行下个语句之前确保当前语句执行完毕: main(){print("main函数开始了");firstString();secondString();thirdString();print("main函数结束了");}firstString()async{print("firstString函数开始了");Future future=Future.delayed(Duration(milliseconds:300),(){return"我是一个字符串";}...
如果可以在不改变函数行为的情况下省略异步,那么就这样做。 Future afterTwoThings(Future first, Future second) {returnFuture.wait([first, second]); } 不推荐写法: Future afterTwoThings(Future first, Future second)async{returnFuture.wait([first, second]); } 不要使用new Dart2使new 关键字可选 推荐...
Future afterTwoThings(Future first, Future second) { return Future.wait([first, second]); } 1. 2. 3. 不推荐写法: Future afterTwoThings(Future first, Future second) async { return Future.wait([first, second]); } 1. 2. 3. 不要使用new Dart2使new 关键字可选 推荐写法: Widget build(...
(firstImage,secondImage)=await(File('image0.jpg').readAsBytes(),File('image1.jpg').readAsBytes()).wait;finalprompt=TextPart("What's different between these pictures?");finalimageParts=[DataPart('image/jpeg',firstImage),DataPart('image/jpeg',secondImage),];finalresponse=awaitmodel....
Column( children: [ Text('First Text'), Text('Second Text'), Text('Third Text'), ], ) 在这个例子中,三个Text组件将会垂直排列。 Row Row是水平布局组件,它允许开发者将子Widget水平排列。例如: Row( children: [ Text('First Text'), Text('Second Text'), Text('Third Text'), ], ) 在这...
test(){List<Map>dataList=List.generate(10,(index){return{"name":"$index号","age":"${index+20}","second":index%2==0?1:4};});AsyncCountFuture.waitBuilder(itemCount:10,itemBuilder:(index)async{finalitem=dataList[index];if(index%2==0){awaitasyncTask1(item["name"],item["age"],...
51. 52. 53. 54. 55. 56. 57. 58. 59. 60. Stack Stack 是一个用于将多个小部件(Widgets)叠加在一起的布局小部件。Stack 允许您将小部件堆叠在其他小部件之上,这样可以创建各种复杂的布局,例如叠加式用户界面元素,重叠的图像和文本等。 Stack 的主要特点和用法包括: 子部件的堆叠:Stack 可以包含多个子...
///voidawaitWithFuture()async{Future future1=Future.delayed(Duration(seconds:2),(){print(1);return1;});Future future2=Future((){print(2);return2;});Future future3=Future((){print(3);return3;});Future.wait([future1,future2,future3]).then((value){print(value);}).catchError((error...
However, if we instead await the timeoutFuture (switch the comment to await resultFuture) we only wait for 1 second until the timeout happens and thrown Exception does NOT get catched. Anybody knows how to wait only for the timeout but still catch an exception thrown in the async task ?