一般的Andr​​oid忠告：全局变量 [英] General Android Advice: Global Variables

问题描述

我想知道什么是来处理Android应用程序的全局变量的最佳途径。例如，我只是想创建一个基本的登录/注册系统。我创建了一个用户类（即具有各种属性像用户名，密码等），这样，当我们去登记活动中，用户类的构造函数被调用来创建一个唯一的用户对象，一旦所有的领域都充满出。当时我想的是只要有User类型的全球ArrayList的，这样我可以通过刚上的所有登录尝试的用户环路。

I was wondering what is the best way to handle global variables for android apps. For example, I'm just trying to create a basic login/register system. I've created a user class (that has various attributes like username, password, etc..), so that when we go to the register activity, the User class constructor is called to create a unique user object once all the fields are filled out. I was then thinking of simply having a global arrayList of type User so that I could just loop through all the users on a login attempt.

到目前为止，（由于组合缺乏java的经验，是非常新的这个机器人的东西），我一直没能成功地实现这一点。我有一个类，我称之为globalStuff，它有一堆公共静态变量（即用户列表和当前用户），我认为可以从用户导航到任何活动进行访问的。

So far (due to a combined lack of experience in java, and being very new to this android stuff), I haven't been able to implement this successfully. I have a class which I call "globalStuff" which has a bunch of public static variables (i.e. the list of users and current user), which I thought could be accessed from any activity the user navigates to.

必须有一个更好的方式去这件事。我一直在读通过一些教程和这里几个帖子，但没有解决这个很基本的想法。所以，这将是接近这样的事情的最好方法？

There must be a better way to go about this. I've been reading through a few tutorials and a few posts on here, but none address this very basic idea. So what would be the best way to approach something like this?

感谢您的帮助！

推荐答案

这就是所谓的静态单，它看起来是这样的：

It's called a static singleton and it looks like this:

public class Global {

    private static Global instance = null;

    public static Global getInstance() {
        if( instance == null )
            instance = new Global();
        return instance;
    }

    // additional methods, members, etc...

}

然后你只需指它在你的code为：

Then you just refer to it in your code as:

Global.getInstance().getUserList();

等。

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