如何检查是否共享preferences文件存在与否 [英] How to check if SharedPreferences file exists or not

问题描述

我要寻找一个机器人共享preferences我想知道有没有办法只检查是否preferences文件是否存在。

I am looking an android Shared Preferences and I am wondering is there a way to just check if the preferences file exists.

   SharedPreferences  mySharedPreferences ; 
mySharedPreferences=getSharedPreferences("Name_of_your_preference",mode);

这上面code使我相信​​Name_of_Your_ preferene存储为文件或某种容器将包含preferences。

This above code leads me to believe that "Name_of_Your_preferene" is stored as a file or some sort of container that will contain your preferences.

我想知道有没有去检查，如果它存在与否。当用户加载了一个活动我想所有的设置保存到该文件中一些默认值（关闭所有的设置）。不过，我只希望这样做，如果他们要在页面的第一次。

I am wondering is there away to check if this exists or not. When a user loads up an activity I want to save all the settings into this file with some default values(off for all settings). However I only want to do this if they are going to the page for the first time.

否则，如果我每次都做这样的事情在页面加载

Otherwise if I would do something like this every time the page loads up

SharedPreferences.Editor editor= mySharedPreferences.edit();

/* now store your primitive type values. In this case it is true, 1f and Hello! World  */

editor.putBolean("myBoolean",true);

editor.putFloat("myFloat",1f);

editor.putString("myString"," Hello! World");

我猜测它甚至会覆盖所有设置，他们成立的。

I am guessing it would override all settings even ones they set.

推荐答案

的共享preferences保存在一个XML文件中。你可以找到它在/data/data/your_application_package/shared_$p$pfs/Name_of_your_$p$pference.xml

The SharedPreferences are saved in a xml file. You can find it in /data/data/your_application_package/shared_prefs/Name_of_your_preference.xml

要检查是否共享preferences'Name_of_your_ preference'存在：

To check if the SharedPreferences 'Name_of_your_preference' exist :

File f = new File(
"/data/data/your_application_package/shared_prefs/Name_of_your_preference.xml");
if (f.exists())
    Log.d("TAG", "SharedPreferences Name_of_your_preference : exist");
else
    Log.d("TAG", "Setup default preferences");

问候。

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