flutter —— getx 中各种工具方法

2022-01-23 15:00:21 阅读：460 来源： 互联网

标签：obs name Get value final getx print 工具 flutter

本地化

略（建议配合 get_cli 相关命令使用）

更新 locale

var locale = Locale('en', 'US');
Get.updateLocale(locale);

获取系统的 locale

return GetMaterialApp(
    locale: Get.deviceLocale,
);

切换主题

Get.changeTheme(Get.isDarkMode? ThemeData.light(): ThemeData.dark());

GetPage 中间层

示例：

// 设置中间层
GetPage(
  name: AppRoutes.Main,
  page: () => MainScreen(),
  middlewares: [
    RouteAuthMiddleware(priority: 1),
  ],
),

// 定义中间层
class RouteAuthMiddleware extends GetMiddleware {
  RouteAuthMiddleware({required int priority}) : super(priority: priority);

  @override
  RouteSettings? redirect(String? route) {
    var isLogin = SpUtil.getBool("isLogin");
    if (isLogin == null || !isLogin) {
      Future.delayed(Duration(seconds: 1), () => Get.snackbar("提示", "请先登录APP"));
      return RouteSettings(name: AppRoutes.Login);
    } else {
      return null;
    }
  }
}

日志聚合

GetMaterialApp(
  enableLog: true,
  logWriterCallback: localLogWriter,
);

void localLogWriter(String text, {bool isError = false}) {
  // pass the message to your favourite logging package here
  // please note that even if enableLog: false log messages will be pushed in this callback
  // you get check the flag if you want through GetConfig.isLogEnable
}

.obs 变量的更新

final name = 'GetX'.obs;
// only "updates" the stream, if the value is different from the current one.
name.value = 'Hey';

// All Rx properties are "callable" and returns the new value.
// but this approach does not accepts `null`, the UI will not rebuild.
name('Hello');

// is like a getter, prints 'Hello'.
name() ;

/// numbers:

final count = 0.obs;

// You can use all non mutable operations from num primitives!
count + 1;

// Watch out! this is only valid if `count` is not final, but var
count += 1;

// You can also compare against values:
count > 2;

/// booleans:

final flag = false.obs;

// switches the value between true/false
flag.toggle();


/// all types:

// Sets the `value` to null.
flag.nil();

// All toString(), toJson() operations are passed down to the `value`
print( count ); // calls `toString()` inside  for RxInt

final abc = [0,1,2].obs;
// Converts the value to a json Array, prints RxList
// Json is supported by all Rx types!
print('json: ${jsonEncode(abc)}, type: ${abc.runtimeType}');

// RxMap, RxList and RxSet are special Rx types, that extends their native types.
// but you can work with a List as a regular list, although is reactive!
abc.add(12); // pushes 12 to the list, and UPDATES the stream.
abc[3]; // like Lists, reads the index 3.


// equality works with the Rx and the value, but hashCode is always taken from the value
final number = 12.obs;
print( number == 12 ); // prints > true

/// Custom Rx Models:

// toJson(), toString() are deferred to the child, so you can implement override on them, and print() the observable directly.

class User {
    String name, last;
    int age;
    User({this.name, this.last, this.age});

    @override
    String toString() => '$name $last, $age years old';
}

final user = User(name: 'John', last: 'Doe', age: 33).obs;

// `user` is "reactive", but the properties inside ARE NOT!
// So, if we change some variable inside of it...
user.value.name = 'Roi';
// The widget will not rebuild!,
// `Rx` don't have any clue when you change something inside user.
// So, for custom classes, we need to manually "notify" the change.
user.refresh();

// or we can use the `update()` method!
user.update((value){
  value.name='Roi';
});

print( user );

GetView

直接注入 controller 实例

 class AwesomeController extends GetController {
   final String title = 'My Awesome View';
 }

  // ALWAYS remember to pass the `Type` you used to register your controller!
 class AwesomeView extends GetView<AwesomeController> {
   @override
   Widget build(BuildContext context) {
     return Container(
       padding: EdgeInsets.all(20),
       child: Text(controller.title), // just call `controller.something`
     );
   }
 }

GetxService

用于代理 GetxController，并且不会自动销毁。常用于 ApiService, StorageService, CacheService 等。仅能通过 Get.reset 删除

Future<void> main() async {
  await initServices(); /// AWAIT SERVICES INITIALIZATION.
  runApp(SomeApp());
}

/// Is a smart move to make your Services intiialize before you run the Flutter app.
/// as you can control the execution flow (maybe you need to load some Theme configuration,
/// apiKey, language defined by the User... so load SettingService before running ApiService.
/// so GetMaterialApp() doesnt have to rebuild, and takes the values directly.
void initServices() async {
  print('starting services ...');
  /// Here is where you put get_storage, hive, shared_pref initialization.
  /// or moor connection, or whatever that's async.
  await Get.putAsync(() => DbService().init());
  await Get.putAsync(SettingsService()).init();
  print('All services started...');
}

class DbService extends GetxService {
  Future<DbService> init() async {
    print('$runtimeType delays 2 sec');
    await 2.delay();
    print('$runtimeType ready!');
    return this;
  }
}

class SettingsService extends GetxService {
  void init() async {
    print('$runtimeType delays 1 sec');
    await 1.delay();
    print('$runtimeType ready!');
  }
}

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标签：obs,name,Get,value,final,getx,print,工具,flutter
来源： https://www.cnblogs.com/lemos/p/15836412.html

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