未处理的异常：MissingPluginException（在通道 flutter.baseflow.com/permissions/methods 上未找到方法 requestPermissions 的实现）

Question

我正在尝试制作一个个人资料页面，用户可以在其中上传他们的个人资料图片。我已经完成了所有必需的方法，但弹出此错误：

Unhandled Exception: MissingPluginException(No implementation found for method requestPermissions on channel flutter.baseflow.com/permissions/methods)

当我按下

IconButton

请求许可时，应该会弹出一个选项卡，但在这里什么也没有发生，只是弹出上述错误。

这是我所做的代码：

import 'dart:io';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:image_picker/image_picker.dart';
import 'package:permission_handler/permission_handler.dart';

class EditProfilePage extends StatefulWidget {
  @override
  _EditProfilePageState createState() => _EditProfilePageState();
}

class _EditProfilePageState extends State<EditProfilePage> {
  bool showPassword = false;
  String imageUrl;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).scaffoldBackgroundColor,
        elevation: 1,
        leading: IconButton(
          icon: Icon(
            Icons.arrow_back,
            color: Colors.orangeAccent,
          ),
          onPressed: () {
            Navigator.pop(context);
          },
        ),
      ),
      body: Container(
        padding: EdgeInsets.only(left: 16, top: 25, right: 16),
        child: GestureDetector(
          onTap: () {
            FocusScope.of(context).unfocus();
          },
          child: ListView(
            children: [
              Text(
                "Edit Profile",
                style: TextStyle(fontSize: 25, fontWeight: FontWeight.w500),
              ),
              SizedBox(
                height: 15,
              ),
              Center(
                child: Stack(
                  children: [
                    Container(
                      child: (imageUrl != null)
                          ? Image.network(imageUrl)
                          : Image.asset('assets/background.jpg'),
                      width: 130,
                      height: 130,
                      decoration: BoxDecoration(
                          border: Border.all(
                              width: 4,
                              color: Theme.of(context).scaffoldBackgroundColor),
                          boxShadow: [
                            BoxShadow(
                                spreadRadius: 2,
                                blurRadius: 10,
                                color: Colors.black.withOpacity(0.1),
                                offset: Offset(0, 10))
                          ],
                          shape: BoxShape.circle,
                      ),
                    ),
                    Positioned(
                        bottom: 0,
                        right: 0,
                        child: Container(
                          height: 40,
                          width: 40,
                          decoration: BoxDecoration(
                            shape: BoxShape.circle,
                            border: Border.all(
                              width: 4,
                              color: Theme.of(context).scaffoldBackgroundColor,
                            ),
                            color: Colors.orangeAccent,
                          ),
                          child: IconButton(
                            icon: Icon(Icons.edit),
                            color: Colors.white,
                            onPressed: () => uploadImage(),
                          ),
                        )),
                  ],
                ),
              ),
              SizedBox(
                height: 35,
              ),
              buildTextField("Full Name", "Yeap Wei Kang", false),
              buildTextField("E-mail", "[email protected]", false),
              buildTextField("Password", "********", true),
              buildTextField("Location", "Ipoh, Perak", false),
              SizedBox(
                height: 35,
              ),
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  OutlineButton(
                    padding: EdgeInsets.symmetric(horizontal: 50),
                    shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(20)),
                    onPressed: () {
                      Navigator.pop(context);
                    },
                    child: Text("CANCEL",
                        style: TextStyle(
                            fontSize: 14,
                            letterSpacing: 2.2,
                            color: Colors.black)),
                  ),
                  RaisedButton(
                    onPressed: () {
                      Navigator.pop(context);
                    },
                    color: Colors.orangeAccent,
                    padding: EdgeInsets.symmetric(horizontal: 50),
                    elevation: 2,
                    shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(20)),
                    child: Text(
                      "SAVE",
                      style: TextStyle(
                          fontSize: 14,
                          letterSpacing: 2.2,
                          color: Colors.white),
                    ),
                  )
                ],
              )
            ],
          ),
        ),
      ),
    );
  }

  Widget buildTextField(
      String labelText, String placeholder, bool isPasswordTextField) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 35.0),
      child: TextField(
        obscureText: isPasswordTextField ? showPassword : false,
        decoration: InputDecoration(
            suffixIcon: isPasswordTextField
                ? IconButton(
              onPressed: () {
                setState(() {
                  showPassword = !showPassword;
                });
              },
              icon: Icon(
                Icons.remove_red_eye,
                color: Colors.grey,
              ),
            )
                : null,
            contentPadding: EdgeInsets.only(bottom: 3),
            labelText: labelText,
            floatingLabelBehavior: FloatingLabelBehavior.always,
            hintText: placeholder,
            hintStyle: TextStyle(
              fontSize: 16,
              fontWeight: FontWeight.bold,
              color: Colors.black,
            )),
      ),
    );
  }
  uploadImage() async {
    final _storage = FirebaseStorage.instance;
    final _picker = ImagePicker();
    PickedFile image;


    //Check Permissions
    await Permission.photos.request();

    var permissionStatus = await Permission.photos.status;

    if (permissionStatus.isGranted){
      //Select Image
      image = await _picker.getImage(source: ImageSource.gallery);
      var file = File(image.path);

      if (image != null){
        //Upload to Firebase
        var snapshot = await _storage.ref()
            .child('folderName/imageName')
            .putFile(file);

        var downloadUrl = await snapshot.ref.getDownloadURL();

        setState(() {
          imageUrl = downloadUrl;
        });
      } else {
        print('No Path Received');
      }

    } else {
      print('Grant Permissions and try again');
    }




  }
}

谁能告诉我我的编码有什么问题吗？

Answer 1

停止正在运行的应用程序，转到终端 > flutter clean > 然后再次构建应用程序

Answer 2

您好，我也遇到了同样的问题，请问您解决了吗？