为什么此警报对话框无法正常工作

Question

每当用户单击特定列表项时，我使用下面的代码来获取警报

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





class RamList extends StatelessWidget {



  @override
  Widget build(BuildContext context) {



    return _myListView(context);
  }
}

Widget _myListView(BuildContext context) {
  final titles = [
     'Part-1',
     'part-2',
     'part-3',
     'part-4',
     'part-5',
  ];

  final numbers = [
    '1 ',
    '2 ',
    '3 ',
    '4 ',
    '5 ',



  ];

  functionOne() {
    Navigator.push(
        context, new MaterialPageRoute(builder: (context) =>  RamOne()));
  }

  functionTwo() {
    Navigator.push(context, MaterialPageRoute(builder: (context) => RamTwo()));
  }

  functionThree() {
    Navigator.push(
        context, MaterialPageRoute(builder: (context) => RamThree()));
  }

  functionFour() {
    Navigator.push(context, MaterialPageRoute(builder: (context) => RamFour()));
  }

  functionFive()=>_onAlertButtonPressed1; 





  final List<Function> onTaps = [
    functionOne,
    functionTwo,
    functionThree,
    functionFour,
    functionFive,

  ];

  return ListView.builder(

      itemCount: titles.length,
      itemBuilder: (context, index) {
        return Card(
            elevation: 50,
            child: InkWell(



              child: Row(
                children: <Widget>[


                  Container(


                    height: 100.0,
                    width:50.0,

                    decoration: BoxDecoration(
                        gradient:LinearGradientStyle.linearGradient(
                            orientation:LinearGradientStyle.ORIENTATION_HORIZONTAL,
                            gradientType: LinearGradientStyle.GRADIENT_TYPE_AMIN
                        )
                    ),),

                  Container(
                      margin: EdgeInsets.all(10),
                      child: Text(
                        numbers[index],
                      )),


                 Flexible(child:  Container(
                    margin: EdgeInsets.all(10),
                    child: GradientText((titles[index]),
                      gradient:gradient,

                      style:TextStyle(fontSize:20.0,fontWeight:FontWeight.bold, ),
                    ),

                  ))
                ],
              ),
              onTap: () => onTaps[index](),
            ));
      });


}

_onAlertButtonPressed1(context) {
  Alert(
    context: context,
    type: AlertType.info,
    title: "Coming soon",
    desc: "This link will be available in future updates",

  ).show();
}

我尝试使用 rflutter alert 来显示警报。一切正常，没有任何错误。但是点击 destination listview 后没有出现警报.. 为什么这段代码不起作用。如果您有任何解决方案，请帮助我..

如果您需要更多信息，请发表评论。顺便说一下控制台消息工作正常。控制台框中没有错误消息。

Answer 1

你有这个回调： functionFive()=>_onAlertButtonPressed;

它调用 __onAlertButtonPressed_，但显示对话框的函数称为 _onAlertButtonPressed1（它的末尾有 1）。

UPD：您的回调应该接受上下文并且 functionFive 应该调用 _onAlertButtonPressed1 函数：

  functionOne(BuildContext context) {
    Navigator.push(
        context, new MaterialPageRoute(builder: (context) => RamOne()));
  }

  functionTwo(BuildContext context) {
    Navigator.push(context, MaterialPageRoute(builder: (context) => RamTwo()));
  }

  functionThree(BuildContext context) {
    Navigator.push(
        context, MaterialPageRoute(builder: (context) => RamThree()));
  }

  functionFour(BuildContext context) {
    Navigator.push(context, MaterialPageRoute(builder: (context) => RamFour()));
  }

  functionFive(BuildContext context) => _onAlertButtonPressed1(context); 

并将上下文传递给回调：

onTap: () => onTaps[index](context),

Answer 2

要在颤振中显示警报对话框，您必须执行以下操作：

_onAlertButtonPressed1(context) {
         AlertDialog alert = AlertDialog(
               title: Text("Coming soon"),
               content: Text("This link will be available in future updates"),
               actions: [
                 //your actions (I.E. a button)
               ],
             );

            // show the dialog
               showDialog(
                    context: context,
                    builder: (BuildContext context) {
                    return alert;
                   },
               );
    }

您可以查看文档here。

还有一篇文章解释了如何使用 AlertDialog here。