Question

我正在尝试显示警报。我正在使用rflutter包。但这不起作用，我不明白。

这是我的main.dart

import 'package:flutter/material.dart';
import 'package:rflutter_alert/rflutter_alert.dart';

void main() => runApp(DialogueBoxes());

class DialogueBoxes extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      color: Colors.green,
      home: Scaffold(
        body: Center(
          child: Container(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                FlatButton(
                  child: Text("Click Flat"),
                  onPressed: () {
                    return Alert(
                      context: context,
                      title: 'Flat Cilcked',
                    ).show();
                  },
                ),
                RaisedButton(
                  child: Text("Click Raised"),
                  onPressed: () => Alert(
                    context: context,
                    title: 'Raised Click',
                  ).show(),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }
}

这是pubspec.yaml依赖项

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^0.1.2
  rflutter_alert: ^1.0.3

这是我遇到的错误。

E/flutter (27156): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: NoSuchMethodError: The getter 'modalBarrierDismissLabel' was called on null.
E/flutter (27156): Receiver: null
E/flutter (27156): Tried calling: modalBarrierDismissLabel
E/flutter (27156): #0      Object.noSuchMethod (dart:core-patch/object_patch.dart:51:5)
E/flutter (27156): #1      Alert.show (package:rflutter_alert/src/alert.dart:54:55)
E/flutter (27156): <asynchronous suspension>
E/flutter (27156): #2      DialogueBoxes.build.<anonymous closure> (package:quizzed/main.dart:32:21)
E/flutter (27156): #3      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:654:14)
E/flutter (27156): #4      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:729:32)
E/flutter (27156): #5      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
E/flutter (27156): #6      TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:365:11)
E/flutter (27156): #7      TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:275:7)
E/flutter (27156): #8      PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:455:9)
E/flutter (27156): #9      PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:75:13)
E/flutter (27156): #10     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:102:11)
E/flutter (27156): #11     GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:218:19)
E/flutter (27156): #12     GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198:22)
E/flutter (27156): #13     GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
E/flutter (27156): #14     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
E/flutter (27156): #15     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
E/flutter (27156): #16     _rootRunUnary (dart:async/zone.dart:1136:13)
E/flutter (27156): #17     _CustomZone.runUnary (dart:async/zone.dart:1029:19)
E/flutter (27156): #18     _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)
E/flutter (27156): #19     _invoke1 (dart:ui/hooks.dart:263:10)
E/flutter (27156): #20     _dispatchPointerDataPacket (dart:ui/hooks.dart:172:5)
E/flutter (27156):

帮我解决这个问题。
我尝试了许多其他方法，但没有成功。
提前谢谢。

Answer 1

您需要拆分家庭小部件，尝试将Scaffold切换到另一个StatelessWidget，然后从MaterialApp home调用它

编辑像这样MaterialApp

来改变您的home: home()家

这是您在另一个Scaffold中的新home() StatelessWidget

class home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Container(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              FlatButton(
                child: Text("Click Flat"),
                onPressed: () {
                  return Alert(
                    context: context,
                    title: 'Flat Cilcked',
                  ).show();
                },
              ),
              RaisedButton(
                child: Text("Click Raised"),
                onPressed: () => Alert(
                  context: context,
                  title: 'Raised Click',
                ).show(),
              )
            ],
          ),
        ),
      ),
    );
  }
}

Answer 2

您的问题看起来像不是引用上下文参数。

尝试一下。

 RaisedButton(
    child : Text("Click Raised),
    onPressed : () => _showAlert(context),
 )

...
//Out of build method
_showAlert(context){
       Alert(
          context : context,
          title : 'Raised Click',
       ).show();
}

颤振警报问题。 rflutter不起作用

2 个答案: