Question

我是Bloc模式的新手，因此在更新用image_picker选择的图像时遇到了一些麻烦。

到目前为止，这是我的代码

image_picker_provider.dart

import 'dart:io';

import 'package:image_picker/image_picker.dart';

class ImagePickerProvider {
  Future<File> getImage() async {
    File image = await ImagePicker.pickImage(
        source: ImageSource.gallery, maxWidth: 150.0, maxHeight: 150.0);
    return image;
  }

  Future<File> takeImage() async {
    var image = await ImagePicker.pickImage(
        source: ImageSource.camera, maxWidth: 150.0, maxHeight: 150.0);
    return image;
  }
}

repository.dart

  Future<File> getImage() => _imagePickerProvider.getImage();

  Future<File> takeImage() => _imagePickerProvider.takeImage();

form.dart

  Widget picture() {
    return StreamBuilder(
        stream: _bloc.profilePicture,
        builder: (BuildContext context, AsyncSnapshot<Future<File>> snapshot) {
          if (!snapshot.hasData || snapshot.hasError) {
            return defaultPicture();
          } else {
            return profilePicture(snapshot);
          }
        });
  }

  Widget defaultPicture() {
    return Container(
      width: 150.0,
      height: 150.0,
      decoration: new BoxDecoration(
        image: new DecorationImage(
          image: AssetImage("assets/defaultProfile.jpg"),
          fit: BoxFit.cover,
        ),
        borderRadius: new BorderRadius.all(new Radius.circular(128.0)),
        border: new Border.all(
          color: Colors.black,
          width: 1.0,
        ),
      ),
    );
  }

  Widget profilePicture(File snapshotData) {
    return Container(
      width: 150.0,
      height: 150.0,
      decoration: new BoxDecoration(
        image: new DecorationImage(
          image: FileImage(snapshotData),
          fit: BoxFit.cover,
        ),
        borderRadius: new BorderRadius.all(new Radius.circular(128.0)),
        border: new Border.all(
          color: Colors.black,
          width: 1.0,
        ),
      ),
    );
  }

到目前为止，我所拥有的关于个人资料图片的所有信息

create_account_bloc.dart

import 'dart:async';
import 'dart:io';
import 'package:rxdart/rxdart.dart';
import '../resources/repository.dart';

class CreateAccountBloc {
  final _repository = Repository();
  final _email = BehaviorSubject<String>();
  final _password = BehaviorSubject<String>();
  final _firstName = BehaviorSubject<String>();
  final _phoneNumber = BehaviorSubject<int>();
  final _profilePicture = BehaviorSubject<Future<File>>();
  final _profilePictureURL = BehaviorSubject<String>();
  final _createAccountStatus = BehaviorSubject<CreateAccountStatus>();

  Observable<String> get email => _email.stream.transform(_validateEmail);

  Observable<String> get password =>
      _password.stream.transform(_validatePassword);

  Observable<String> get firstName =>
      _firstName.stream.transform(_validateFirstName);

  Observable<CreateAccountStatus> get createAccountStatus =>
      _createAccountStatus.stream;

  Observable<Future<File>> get profilePicture => _profilePicture.stream;

  String get emailAddress => _email.value;

  // Change data
  Function(String) get changeEmail => _email.sink.add;

  Function(String) get changePassword => _password.sink.add;

  Function(String) get changeFirstName {
    return _firstName.sink.add;
  }

  Function(CreateAccountStatus) get changeAccountStatus =>
      _createAccountStatus.sink.add;

  final _validateEmail =
      StreamTransformer<String, String>.fromHandlers(handleData: (email, sink) {
    if (Validator.isValidEmail(email)) {
      sink.add(email);
    } else {
      sink.addError(StringConstant.emailValidateMessage);
    }
  });

  final _validatePassword = StreamTransformer<String, String>.fromHandlers(
      handleData: (password, sink) {
    if (password.length >= 6) {
      sink.add(password);
    } else {
      sink.addError(StringConstant.passwordValidateMessage);
    }
  });

  final _validateFirstName = StreamTransformer<String, String>.fromHandlers(
      handleData: (firstName, sink) {
    if (Validator.isValidFirstName(firstName)) {
      sink.add(firstName);
    } else {
      sink.addError(StringConstant.firstNameValidateMessage);
    }
  });

  bool validateFields() {
    if (Validator.isNotNullEmptyFalseOrZero(_email.value) &&
        Validator.isNotNullEmptyFalseOrZero(_password.value) &&
        Validator.isValidFirstName(_firstName.value) &&
//        _phoneNumber.value != null &&
////        _phoneNumber.value.is &&
//        _profilePicture.value != null &&
//        _profilePicture.value.isNotEmpty &&
        Validator.isValidEmail(_email.value) &&
        _password.value.length >= 6) {
      return true;
    } else {
      return false;
    }
  }

  void dispose() async {
    await _email.drain();
    _email.close();
    await _password.drain();
    _password.close();
    await _firstName.drain();
    _firstName.close();
    await _phoneNumber.drain();
    _phoneNumber.close();
    await _profilePicture.drain();
    _profilePicture.close();
    await _profilePictureURL.drain();
    _profilePictureURL.close();
    await _createAccountStatus.drain();
    _createAccountStatus.close();
  }
}

我试图复制其他部分并使它们正常工作，但是每次旅途中我似乎都会遇到错误。

关于如何从图库中选择图像并更新_bloc.profilePicture的任何想法？

谢谢！

Answer 1

我不太确定您拥有什么，还没有尝试过。

但是我能够使您的代码像这样

create_account_bloc.dart

final _profilePicture = BehaviorSubject<File>();

Observable<File> get profilePicture => _profilePicture.stream;

Function(File) get changeProfilePicture => _profilePicture.sink.add;
  void getImage() {
  _repository.getImage().then((value) {
    _profilePicture.sink.add(value);
  });
}

void takeImage() {
  _repository.takeImage().then((value) {
    _profilePicture.sink.add(value);
  });
}

如何使用Image_picker和bloc更新图像

1 个答案: