dart

问题 class LevelUp extends GetxController { Map<String, String> params = Get.arguments; var myTest = params.[comLevel]; } Error report--"The instance member 'params' can't be accessed in an initializer." I am new to programming and this is being called directly from a widget. I checked the LevelUp map and it has contents. The error occurs where I am trying to assign the param value to myTest. It doesn't matter if I put the key in quotes or provide an integer. Any advice would be greatly

问题 class LevelUp extends GetxController { Map<String, String> params = Get.arguments; var myTest = params.[comLevel]; } Error report--"The instance member 'params' can't be accessed in an initializer." I am new to programming and this is being called directly from a widget. I checked the LevelUp map and it has contents. The error occurs where I am trying to assign the param value to myTest. It doesn't matter if I put the key in quotes or provide an integer. Any advice would be greatly

问题 class LevelUp extends GetxController { Map<String, String> params = Get.arguments; var myTest = params.[comLevel]; } Error report--"The instance member 'params' can't be accessed in an initializer." I am new to programming and this is being called directly from a widget. I checked the LevelUp map and it has contents. The error occurs where I am trying to assign the param value to myTest. It doesn't matter if I put the key in quotes or provide an integer. Any advice would be greatly

问题 class LevelUp extends GetxController { Map<String, String> params = Get.arguments; var myTest = params.[comLevel]; } Error report--"The instance member 'params' can't be accessed in an initializer." I am new to programming and this is being called directly from a widget. I checked the LevelUp map and it has contents. The error occurs where I am trying to assign the param value to myTest. It doesn't matter if I put the key in quotes or provide an integer. Any advice would be greatly

问题 I need to retrieve a list of days from a date range. The user selects the start date and the end date and it calculates the days in between (start and end included). I tried to use a for loop as follow: List<DateTime> calculateDaysInterval(DateTime startDate, DateTime endDate) { List<DateTime> days = []; for (DateTime d = startDate; d.isBefore(endDate); d.add(Duration(days: 1))) { days.add(d); } return days; } but it doesn't work and it freezes the app. Do you guys have any suggestions?

问题 I am working on a group chat app with Flutter and the Firestore Plugin. Getting the data from the database and converting the snapshot into a List of Messages works totally fine. But now I want to convert the uid from the database into the username (the uids and their usernames are saved in the db). This is my code: final CollectionReference messagesCollection = Firestore.instance.collection('messages'); final CollectionReference usersCollection = Firestore.instance.collection('users');

问题 I am working on a group chat app with Flutter and the Firestore Plugin. Getting the data from the database and converting the snapshot into a List of Messages works totally fine. But now I want to convert the uid from the database into the username (the uids and their usernames are saved in the db). This is my code: final CollectionReference messagesCollection = Firestore.instance.collection('messages'); final CollectionReference usersCollection = Firestore.instance.collection('users');

问题 I am trying to make a Flutter app where the user can sign in into multiple accounts (different email IDs) and can switch between them from the UserAccounsDrawerHeader . For example, in Gmail app, users can switch between multiple Gmail accounts. Is this possible using Firebase Auth for Flutter? 回答1: In the default scenario, Firebase Auth generally does not support allowing a user to be signed in with multiple accounts at the same time. If you want to add support, what you will have to do is

问题 I am trying to make a Flutter app where the user can sign in into multiple accounts (different email IDs) and can switch between them from the UserAccounsDrawerHeader . For example, in Gmail app, users can switch between multiple Gmail accounts. Is this possible using Firebase Auth for Flutter? 回答1: In the default scenario, Firebase Auth generally does not support allowing a user to be signed in with multiple accounts at the same time. If you want to add support, what you will have to do is

问题 I am trying to make a Flutter app where the user can sign in into multiple accounts (different email IDs) and can switch between them from the UserAccounsDrawerHeader . For example, in Gmail app, users can switch between multiple Gmail accounts. Is this possible using Firebase Auth for Flutter? 回答1: In the default scenario, Firebase Auth generally does not support allowing a user to be signed in with multiple accounts at the same time. If you want to add support, what you will have to do is