Question

我正在创建一个数据表并从 api 获取行中的值，并添加一个编辑图标按钮并单击编辑图标我想打开一个弹出对话框。但是当我点击编辑图标时，它会向我发送这个错误

错误：

[ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: 'package:flutter/src/widgets/navigator.dart': Failed assertion: line 3018 pos 18: '!navigator._debugLocked': is not true.

这是点击编辑图标后我的屏幕快照

这是我的代码


class MyAttendance extends StatefulWidget {
  

  @override
  _MyAttendanceState createState() => _MyAttendanceState();
}

class _MyAttendanceState extends State<MyAttendance> {
  TextEditingController descriptionController;
  TextEditingController timeinController;
  TextEditingController timeoutController;


//this is my pop up dialogue box code


  showAlertDialog(BuildContext context) {  
  // Create button  
  Widget okButton = FlatButton(  
    child: Text("Submit",style: TextStyle(fontWeight: FontWeight.bold,color: Colors.blue[900],fontSize: 20),),  
    onPressed: () {  
      Navigator.of(context).pop(); 
    },  
  );  
  
  // Create AlertDialog  
  AlertDialog alert = AlertDialog(  
    insetPadding: EdgeInsets.symmetric(vertical: 160),
    title: Text("Request to change time",style: TextStyle(fontWeight: FontWeight.bold,color: Colors.blue[500])),  
    content: Column(children:<Widget> [
      
      TextField(
        decoration: InputDecoration(labelText: "Description"),
        controller:descriptionController ,
      ),
      TextField(
        decoration: InputDecoration(labelText: "Time in"),
        controller:timeinController ,
      ),
      TextField(
        decoration: InputDecoration(labelText: "Time out"),
        controller:timeoutController ,
      ),
      
      ]),
      
  
    actions: [  
      okButton,  
    ],  
  );  
  
  // show the dialog  
  showDialog(  
    context: context,  
    builder: (BuildContext context) {  
      return alert;  
    },  
  );  
 }
 
  //List<History> _historyList;
  List<History> historyList=[];
  String _selectedLeave;
  int monthIndex;
  int month;
  var monthsList=<String>[
      'January',
      'Febuary',
      'March',
      'April',
      'May',
      'June',
      'July',
      'Augest',
      'September',
      'October',
      'November',
      'December'
  ];
  String getdate="";
    void _getDate() {
    final String formattedDateTime =
        DateFormat('MM').format(DateTime.now()).toString();
    setState(() {
      getdate = formattedDateTime;
     print("date  "+getdate);
    });
  }
  _userDetails() async{
    SharedPreferences myPrefs=await SharedPreferences.getInstance();
    setState(() {
          getname=myPrefs.getString('name');         
        }); 
   }
   void initState() {
      _userDetails();
      _getDate();
      _getRecord();
      
    }
  Future<List<History>> _getRecord() async{
   Dio dio=new Dio();
   var data={
     'username':getname,
     'month':month,
     'token':getaccesstoken
   };
   return dio
    .post(localhostUrlAttendanceHistory,data: json.encode(data))
      .then((onResponse) async {

        Map<String, dynamic> map=onResponse.data;
        print(map);
        List<dynamic> data = map["data"];
        
       
       // print(data[0]["Date"]);
        print("sdf");
        print(data);
        
        print("time in");
        //print(onResponse.data['data'][0]['TimeIn']);
        //List<History> historyList = [];
        for (var h in data) {
          History history = History(
            h["Date"], 
            h["TimeIn"], 
            h["TimeOut"],
          );
          historyList.add(history);
          print(history);
        }
        return historyList;
      })
      .catchError((onerror){
        print(onerror.toString());
       
    });
  }
  Widget attendanceHistory(List<History> 
    
    historyList)=> 
     
   Center(
      child:SingleChildScrollView(
         scrollDirection: Axis.vertical,
        child: SingleChildScrollView(
           scrollDirection: Axis.horizontal,
           child:DataTable(
          decoration: BoxDecoration(border: Border.all(color: Colors.blue[500], width: 2)),
          headingRowColor: MaterialStateColor.resolveWith((states) => Colors.blue[500]),
          headingTextStyle: const TextStyle(fontWeight: FontWeight.bold, color: Colors.white),
          showBottomBorder: true,
          headingRowHeight: 60,
          horizontalMargin: 2,
          columnSpacing: 15,
          
          dataRowColor: MaterialStateColor.resolveWith((states) => Colors.blue[50]),
          dividerThickness: 4,
          
          columns: <DataColumn>[
        DataColumn(label: Text("Date"),),
        DataColumn(label: Text("Time in"),),
        DataColumn(label: Text("Time out"),),
        DataColumn(label: Text("Edit"),)    //here i am creating edit column

        // DataColumn(label: Text("Edit"),
    ],
    rows: 
    
    historyList
      ?.map((element)=>DataRow(
      cells: <DataCell>[
      DataCell(Text(element?.date)),
      DataCell(Text(element?.timeIn)),
      DataCell(Text(element?.timeOut)),

//here i am creating edit icon and calling dialouge box
      DataCell(IconButton(icon:Icon(Icons.edit,color: Colors.blue,),    
      onPressed: (){Navigator.push(context, MaterialPageRoute(builder: (context)=>showAlertDialog(context)));})),
      // DataCell(Icon(Icons.edit)),
    ]) )?.toList()))));
  
  
  TextEditingController fromDate=new TextEditingController();
  TextEditingController toDate=new TextEditingController();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: new MyAppBar(title: Text("My Attendance"),onpressed: (){
       Navigator.push(context, MaterialPageRoute(builder: (context)=>Profile()));
   }),
    
    body:Stack(children: <Widget>[
        Container(
        padding: EdgeInsets.fromLTRB(45, 80, 10, 0),
        child:
        DropdownButton<String>(
        value: _selectedLeave==null?null:monthsList[monthIndex],    
        items: 
          monthsList   
          .map<DropdownMenuItem<String>>((String value) {
            return DropdownMenuItem<String>(
              value: value,
              child: Text(value)
            );
          }).toList(),
          hint:Text(
            "Please choose a month",
          ),
          onChanged: (String value) {
            setState(() {
              _selectedLeave=value;
              monthIndex = monthsList.indexOf(value);
              month=monthIndex+1;
              print(month);
              print(_selectedLeave);
            });
          },
        ),
      ),

    Container(
    padding: EdgeInsets.fromLTRB(15, 150, 0, 0),
    child:SingleChildScrollView(
      scrollDirection: Axis.vertical,
    
    child: FutureBuilder(
    
    future: _getRecord(),
    
    builder: (BuildContext context, AsyncSnapshot<List<History>> snapshot) {
      // Check if the data has been received.
      if (snapshot.hasData) {
        // Return the widget and provide the received data.
        return attendanceHistory(snapshot.data);
      }
      //return Center(child: CircularProgressIndicator(),);
      // print("data");
      // print(snapshot.data);
      return Center(
        heightFactor: 10,
        child:Text("Data is not avaliable",style: TextStyle(color: Colors.blue[900],fontWeight: FontWeight.bold,fontSize: 20),));
      //return attendanceHistory(snapshot.data);
     
    }
  ),
),)

   

    ]));
  }
}

class History {
  
  final String date;
  final String timeIn;
  final String timeOut;
  

  History(this.date, this.timeIn, this.timeOut);

}

我也用过这个

 onPressed: (){SchedulerBinding.instance.addPostFrameCallback((timeStamp) 
      {Navigator.push(context, MaterialPageRoute(builder: (context)=>showAlertDialog(context)));});})),

但它不起作用，同样的错误！

如果有人知道如何修复它，请帮忙，将不胜感激！

未处理的异常：'package:flutter/src/widgets/navigator.dart'：断言失败：第 3018 行 pos 18：'!navigator._debugLocked'：不是真的

0 个答案: