如何解决：Future Provider 6.0.2 找不到正确的提供者 Flutter

发布于 2025-01-16 08:58:42 字数 1647 浏览 3 评论 0原文

我尝试在我的应用程序中使用 Future Provider，但当时将其注册在我的小部件树的顶部，如下所示：


import 'package:flutter/material.dart';
import 'package:flutter_application_9_future_provider/function.dart'; //here is my future class
import 'package:flutter_application_9_future_provider/homescreen.dart'; //here is the screen
import 'package:provider/provider.dart'; 

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  MyApp({Key? key}) : super(key: key);
  Busqueda bus = Busqueda(); // my class is called "Busqueda" and has a method (buscarrequest)that returns a future
  @override
  Widget build(BuildContext context) {
    return FutureProvider(
      initialData: 'vacio',
      create: (context) => bus.buscarrequest(),
      child: const MaterialApp(
        home: Home(),
      ),
    );
  }
}

我收到错误消息：

小部件库捕获异常═══════════════════════════════════ 构建 Home(dirty) 时抛出以下 ProviderNotFoundException：错误：找不到正确的提供商在此主页小部件上方
发生这种情况是因为您使用了不包含提供程序的 BuildContext 由您选择。有一些常见的场景：...

使用 ChangeNotifier Provider 这不会发生，为什么？错误消息中有一些示例，但我尝试了但不起作用：

例如，而不是：
小部件构建（BuildContext上下文）{ 返回提供者<示例>（创建：(_) =>例子（），会抛出 ProviderNotFoundError，因为 `context` 是关联的到作为“Provider”父级的小部件子：文本（context.watch<示例>()）， ), }
考虑使用builder，如下所示：
小部件构建（BuildContext上下文）{ 返回提供者<示例>（创建：(_) =>例子（），我们使用“builder”来获取可以访问提供者的新“BuildContext” 构建器：（上下文）{ 不再投掷返回文本(context.watch<示例>()), } ), }

建议如何解决此错误。提前致谢！

在flutter应用程序中使用未来的提供程序（提供程序：^6.0.2）没有错误。

原文

I try to use Future Provider in my app but at the time to register it on the top of my widget tree like so:


import 'package:flutter/material.dart';
import 'package:flutter_application_9_future_provider/function.dart'; //here is my future class
import 'package:flutter_application_9_future_provider/homescreen.dart'; //here is the screen
import 'package:provider/provider.dart'; 

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  MyApp({Key? key}) : super(key: key);
  Busqueda bus = Busqueda(); // my class is called "Busqueda" and has a method (buscarrequest)that returns a future
  @override
  Widget build(BuildContext context) {
    return FutureProvider(
      initialData: 'vacio',
      create: (context) => bus.buscarrequest(),
      child: const MaterialApp(
        home: Home(),
      ),
    );
  }
}

I get and error that says:

Exception caught by widgets library ═══════════════════════════════════
The following ProviderNotFoundException was thrown building Home(dirty):
Error: Could not find the correct Provider<Busqueda> above this Home Widget
This happens because you used a BuildContext that does not include the provider
of your choice. There are a few common scenarios:...

Using ChangeNotifier Provider this do not happen, why?
There is some example in the error message but I tried it but do not work:

For example, instead of:
Widget build(BuildContext context) {
return Provider<Example>(
create: (_) => Example(),
Will throw a ProviderNotFoundError, because `context` is associated
to the widget that is the parent of `Provider<Example>`
child: Text(context.watch<Example>()),
),
}
consider using builder like so:
Widget build(BuildContext context) {
return Provider<Example>(
create: (_) => Example(),
we use `builder` to obtain a new `BuildContext` that has access to the provider
builder: (context) {
No longer throws
return Text(context.watch<Example>()),
}
),
}