flutter : TextEditingController Only Static member can be accessed in initializer error

Question

我正在将数据从 listmosque.dart 传递到 update_screen.dart 以更新数据。一切正常，但我想设置 textedittingcontroller 的默认值。

TextEditingController _txtnrp = TextEditingController(text: "${widget.nrpUpdate}"); <- this error

我收到消息 Only static members can be accessed in initializers. in ${widget.nrpUpdate}如何解决这个问题？

这是我的 update_screen.dart

import 'package:flutter/material.dart';

class UpdateScreen extends StatefulWidget {
  final String idUpdate;
  final String nrpUpdate;
  final String namaUpdate;
  final String emailUpdate;
  final String jurusanUpdate;
  UpdateScreen(
      {this.idUpdate,
      this.nrpUpdate,
      this.namaUpdate,
      this.emailUpdate,
      this.jurusanUpdate});
  @override
  _UpdateScreenState createState() => _UpdateScreenState();
}

class _UpdateScreenState extends State<UpdateScreen> {
 
 TextEditingController _txtnrp = TextEditingController(text: "${widget.nrpUpdate}"); <- In this line error

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: IconButton(
          icon: Icon(Icons.arrow_left),
          onPressed: () => Navigator.pop(context, false),
        ),
        centerTitle: true,
        title: Text('Update ${widget.namaUpdate}'),
      ),
      body: Container(
        child: Center(
          child: SingleChildScrollView(
            padding: EdgeInsets.all(20),
            scrollDirection: Axis.vertical,
            child: Column(
              children: <Widget>[
                TextField(
                  
                  controller: _txtnrp,
                  keyboardType: TextInputType.number,
                  decoration: InputDecoration(hintText: "NRP"),
                  textAlign: TextAlign.center,
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

如何解决这个问题？谢谢

Answer 1

将其移入initState:

class _UpdateScreenState extends State<UpdateScreen> {

  TextEditingController _txtnrp;

  @override
  void initState() {
     _txtnrp = TextEditingController(text: "${widget.nrpUpdate}");
     super.initState();
  }