使用应用程序上下文中无处不在？ [英] Using Application context everywhere?

问题描述

在一个Android应用程序，有什么不对的以下做法：

In an Android app, is there anything wrong with the following approach:

public class MyApp extends android.app.Application {

    private static MyApp instance;

    public MyApp() {
    	instance = this;
    }

    public static Context getContext() {
    	return instance;
    }

}

和无处不在传递（如SQLiteOpenHelper），其中环境是必需的（而不是漏水，当然）？

and pass it everywhere (e.g. SQLiteOpenHelper) where context is required (and not leaking of course)?

推荐答案

有几个这种方法潜在的问题，但在很多情况下（比如你的例子），它会很好地工作。

There are a couple of potential problems with this approach, though in a lot of circumstances (such as your example) it will work well.

在特别是当有任何与要求背景下的GUI处理处理你要小心。例如，如果你通过应用程序上下文到 LayoutInflater ，你会得到一个异常。一般来说，你的做法是极好的：这是很好的做法，该活动中使用活动的背景下，并通过上下文之外的活动的范围的避免内存泄漏的。

In particular you should be careful when dealing with anything that deals with the GUI that requires a Context. For example, if you pass the application Context into the LayoutInflater you will get an Exception. Generally speaking, your approach is excellent: it's good practice to use an Activity's Context within that Activity, and the Application Context when passing a context beyond the scope of an Activity to avoid memory leaks.

此外，作为替代你的模式，你可以使用电话 getApplicationContext（）在上下文对象（如活动）的快捷方式，以获得应用程序上下文。

Also, as an alternative to your pattern you can use the shortcut of calling getApplicationContext() on a Context object (such as an Activity) to get the Application Context.

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