问题描述
颤振问题。我正在尝试将参数作为命名参数传递给 Widget 构造函数,但出现错误:未定义命名参数 'uri'。下面是我定义类的代码,然后是我实例化 Widget 的代码。我被困住了。非常感谢任何帮助!
//Code defining Widget
class VideoPlayerApp extends StatelessWidget {
VideoPlayerApp({this.uri});
final Text uri;
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Video Player Demo',home: VideoPlayerScreen(),);
}
}
//Code defining sURI and then instantiating Widget
Text sURI = Text(
'https://Flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4');
onpressed: () {
Navigator.push(
context,MaterialPageRoute(
builder: (context) => VideoPlayerApp(uri: sURI),),);
},
解决方法
您应该将 FileIO{
id: dataCSV
source: "C:/Users/Halil/yedekleme/Belgeler/build-serialGui-Desktop_Qt_5_14_2_MinGW_32_bit-Release/data.csv"
}
Timer{
id: timer
interval: 1000
repeat: true
onTriggered: {
if(!dataCSV.readNext())
dataCSV.stop()
}
}
Component.onCompleted: timer.start()
定义为 uri
,而不是 String
。
试试这个:
Text