Question

我正在尝试使用StatefulWidget创建路由。

错误：

I/flutter (23141): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter (23141): The following assertion was thrown building
I/flutter (23141): _OverlayEntry-[LabeledGlobalKey<_OverlayEntryState>#3e9ee](dirty, state: _OverlayEntryState#7b90c):
I/flutter (23141): The builder for route "/" returned null.
I/flutter (23141): Route builders must never return null.

代码：

routes:<String,WidgetBuilder>{
        "/":(_)=>new RouteHome(title: 'Flutter Demo Home Page'),
        ...

class RouteHome extends StatefulWidget {
  RouteHome({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

查询：

为什么不允许使用StatefulWidget？

问题： 如果更改了窗口小部件的基类，则路由的热重新加载失败（StatefulWidget＆lt; - ＆gt; StatelessWidget）。

Answer 1

热重新加载仅用于最小的UI更改。

<强>提供者： “这不是一个问题，使用热重新加载来进行UI中的微小更改。通常你需要在创建新类时执行完全重启。“ - @aziza

为什么StatefulWidget的路由创建失败？

1 个答案: