我定义的共享preferences 在多进程模式使用的一个实例。

I've defined an instance of SharedPreferences that used on multi-process mode.

public class Prefs {

    private static SharedPreferences prefs;
    private static SharedPreferences.Editor editor;

    private static void init(Context context) {

        prefs = context.getSharedPreferences("alaki",
                Context.MODE_MULTI_PROCESS);
        editor = prefs.edit();
    }

// static methods to set and get preferences
}

现在我使用的是带有独立的进程，并在静态的方式我的主要应用程序服务这一类。 一切都很顺利，但有时在共享preferences实例存储的所有数据删除！ 我该如何解决这个问题呢？

Now I'm using this class on a service with separate process and also in my main application process in static way. Everything is going well, but sometimes all stored data on SharedPreferences instance removed! How can I solve this problem?

编辑： 最后，我已经解决了利用IPC我的问题。

Finally I've solved my problem using by IPC.

推荐答案

目前在描述目前还没有办法安全地访问共享preferences 的多个进程，其文档。

There is currently no way of safely accessing SharedPreferences on multiple processes, as described in its documentation.

注：目前这一类不支持跨多个应用   流程。这将在以后添加。

Note: currently this class does not support use across multiple processes. This will be added later.

测试了很多与 MODE_MULTI_PROCESS 之后，我有三个试验分享到：

After testing a lot with MODE_MULTI_PROCESS, I've three trials to share:

1 初始化共享preferences 曾经在每道工序并多次使用。

1- Initialize the SharedPreferences once in each process and use it multiple times.

的问题：的值未如预期反映的每一个过程。因此，每个进程都有自己的共享preferences的价值。

The problem: The values are not reflected in each process as expected. So each process has its own value of the SharedPreferences.

2 - 初始化每个共享preferences 放置或获得。

2- Initialize the SharedPreferences in each put or get.

这实际工作和价值，现在是可以互换的进程之间。

This actually works and the value now is interchangeable between processes.

的问题：有时在积极地访问共享preF，共享preferences文件删除了其所有的内容，如在此的 问题 ，我得到这样的警告日志中：

The problem: sometimes after aggressively accessing the sharedpref, the shared preferences file got deleted with all its content, as described in this issue, and I get this warning in the log:

W/FileUtils﹕ Failed to chmod(/data/data/com.hegazy.multiprocesssharedpref/shared_prefs/myprefs.xml): android.system.ErrnoException: chmod failed: ENOENT (No such file or directory)

您可以找到为什么发生这种情况的问题。

You can find why this happens in the issue.

3 使用同步锁定该放的方法，并在共享preferences设定值。

3- Use synchronization to lock the methods that put and set values in the SharedPreferences.

这是完全错误的;同步不会在原有的工作流程。该共享preferences 实际使用同步在实施，但只保证线程安全，不处理的安全性。这是这里描述得非常好。

This is completely wrong; synchronization doesn't work across processes. The SharedPreferences is actually using synchronization in its implementation, but that only ensures thread safety, not process safety. This is described very well here.