Fluent 2 Advanced (V):json_ Serializable use

The later request for network use is free Bmob , It is recommended to generate entity classes  json_serializable .

Advanced failed .

Add dependency ：

environment:
  sdk: ">=2.15.0-116.0.dev <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.2

  json_annotation: ^4.4.0 # add to 1
dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_lints: ^1.0.0

  build_runner: ^2.1.5 # add to 2
  json_serializable: ^6.1.0 # add to 3

create a file  home_page_bean.dart , Write parameters and construction methods , The second bag needs handwriting , The format is to add .g ：

part 'home_page_bean.g.dart';

Don't worry about mistakes first :

import 'package:json_serializable/json_serializable.dart';

part 'home_page_bean.g.dart';

@JsonSerializable()
class HomePage {
  int? type; // classification , Such as recommendation 
  String? title; // title 
  String? content; // Content 
  String? playnum; // Number of plays 
  String? classname; // classification , Such as film and television , Chase fan, etc 
  String? videoLength; // Video duration 
  String? comments; // Comment on 
  String? up; // Blogger 
  String? videourl; // Video playback link 

  // Construction method 
  HomePage();

}

Manually add fromjson Methods and tojson Method , Don't worry about handwritten errors ：

import 'package:json_annotation/json_annotation.dart';

part 'home_page_bean.g.dart';

@JsonSerializable()
class HomePage {
  int? type; // classification , Such as recommendation 
  String? title; // title 
  String? content; // Content 
  String? playnum; // Number of plays 
  String? classname; // classification , Such as film and television , Chase fan, etc 
  String? videoLength; // Video duration 
  String? comments; // Comment on 
  String? up; // Blogger 
  String? videourl; // Video playback link 

  // Construction method 
  HomePage();

  factory HomePage.fromJson(Map<String, dynamic> json) =>
      _$HomePageFromJson(json);

  Map<String, dynamic> toJson() => _$HomePageToJson(this);
}

And then execute the command ：

 flutter packages pub run build_runner build

Wait to compile the file ：home_page_bean.g.dart

But most of the time, there are problems in the actual project compilation , I haven't passed it for a day . Have to say flutter Compatibility is bad enough . Finally, I created a new project , Plug in installed , After generating it, copy it to my project .

I use the non empty version flutter , Probably encountered problems ：

Compilation goes into an endless loop , Repeat printing ：

 I will  flutter  And  build runner  Use it together , But today it just received this empty error . I even thought I had restored my code changes , But it is still the same mistake .

 error  ：

>[SEVERE] json_serializable:json_serializable on test/widget_test.dart:

>NoSuchMethodError: The getter 'uri' was called on null.
>Receiver: null
>Tried calling: uri
>[INFO] 3.3s elapsed, 1/17 actions completed.
>[INFO] 4.4s elapsed, 1/17 actions completed.
>[INFO] 5.4s elapsed, 1/17 actions completed.
>[INFO] 6.4s elapsed, 1/17 actions completed.
>[INFO] 7.5s elapsed, 1/17 actions completed.
>[INFO] 8.5s elapsed, 1/17 actions completed.
>[INFO] 9.6s elapsed, 1/17 actions completed.
>[INFO] 10.7s elapsed, 1/17 actions completed.
>[INFO] 11.8s elapsed, 1/17 actions completed.
>[INFO] 12.9s elapsed, 1/17 actions completed.
>[INFO] 14.0s elapsed, 1/17 actions completed.
>[INFO] 15.0s elapsed, 1/17 actions completed.
>[INFO] 16.1s elapsed, 1/17 actions completed.
>[INFO] 17.1s elapsed, 1/17 actions completed.
>[WARNING] No actions completed for 15.1s, waiting on:
>  json_serializable:json_serializable on lib/common_widgets/alert_screens.dart
>  json_serializable:json_serializable on lib/common_widgets/app_logo.dart
>  json_serializable:json_serializable on lib/common_widgets/app_tab_bar.dart
>  json_serializable:json_serializable on lib/common_widgets/buttons_widgets.dart
>  json_serializable:json_serializable on lib/common_widgets/cards.dart
>  .. and 11 more
>  [INFO] 18.2s elapsed, 1/17 actions completed.
>  [INFO] 19.3s elapsed, 1/17 actions completed.

The solution is to update the plug-in ：

android studio - flutter build runner not working - The getter 'uri' was called on null - Stack Overflow

Updated plug-ins , and    data_plugin: ^0.0.16 Conflict , The plug-in used here is old , and  json_serializable It's new , I can only reduce the version back .

There are also various error reporting problems , Search found let update plug-ins , Very speechless ：

/D:/rruanjian/flutter/.pub-cache/hosted/pub.flutter-io.cn/source_span-1.7.0/lib/src/file.dart:437:1: Error: This requires the 'extension-methods' experiment to be enabled.

Try enabling this experiment by adding it to the command line when compiling and running.

extension FileSpanExtension on FileSpan {
^^^^^^^^^

/D:/rruanjian/flutter/.pub-cache/hosted/pub.flutter-io.cn/source_span-1.7.0/lib/src/file.dart:437:32: Error: A function declaration needs an explicit list of parameters.

Try adding a parameter list to the function declaration.

extension FileSpanExtension on FileSpan {

...
                               ^^^^^^^^

Something like that . These problems have been circulating , I have solved it for a day .

Some people encounter the problem of the above cycle , Please help me solve it , My configuration is like this , Temporarily removed json_serializable：

environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  http: ^0.12.0+1
  flutter:
    sdk: flutter

  cupertino_icons: ^0.1.2

  data_plugin: ^0.0.16
  json_annotation: ^2.0.0
  fluttertoast: ^8.0.6
  permission_handler: ^5.0.1+1
  shared_preferences: ^0.5.7+3
  underline_indicator: ^0.0.2


dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_lints: ^1.0.0