Question

基本问题：需要在整个flutter应用程序中访问Class。

要求：不要让它成为我访问的有状态窗口小部件。

只希望我可以通过在其他页面上导入来访问一个类。我坚持使用一组变量的用户登录名，并且我不想不必将此对象逐页推送。

想简单地访问类值

我无法使用单例或其他解决方案找到任何很好的例子，这给了我我想要的东西。

import 'package:myApp/models/user.dart';

MyClass.Username = "testUser"; //Set the username

String currentUser = MyClass.Username; // Get the username

//Here is the top of the User class - is this creating a class that will 
//only be defined once in the app, so if I set a value it will persist ?
class User {

static User _user = new User._internal();

factory User() {
  return _user;
}

User._internal();
//More stuff
....}

Answer 1

如果要创建单例类以在应用程序的任何位置访问同一实例，则源代码将显示一个单例类的示例。阅读评论。

class UserRepository {

  static UserRepository _instance = new UserRepository._internal();
  static get instance => _instance; // this is a get method that return _instance private class field
  // the name member is accessible directly like a public field
 String name;

 UserRepository._internal( ){
    name = " singleton name property";
 }

  // this is a instance method
  void myInstanceMethod(){
    print("hello my singleton");
  }
} //end of your singleton class

// usage in any point of your app.
UserRepository.instance.myInstanceMethod();

var myInstance = UserRepository.instance; // getting instance singleton reference
//accessing name class member
print("The name is:  ${myInstance.name}";)
myInstance.name = "user name";
print("Now the name is: ${myInstance.name}" );

//or you can access like this way too
UserRepository.instance.name = " User name";
print("The name is: ${UserRepository.instance.name}" );

基本Flutter类可访问性

1 个答案: