Android的共享preferences多活动 [英] Android Shared preferences with multiple activities

问题描述

如何重新获取已保存从previous活动共享preferences？我是否需要启用文件书面或其他一些明显的改动？

解决方案

您不需要任何特殊的清单modificaiton来实现这一点。

假设你已经保存preferences你可以阅读这些preferences在任何时候做这样的事情我会告诉波纹管。

1. 写的共享preferences文件：

    共享preferences preFS = getShared preferences（your_file_name，MODE_PRIVATE）;
     共享preferences.Editor编辑器= prefs.edit（）;
     editor.putString（yourStringName，this_is_the_saved_value）;
     editor.commit（）; //这一行是很重要的。如果你错过了这一次它不是要去工作！
    

2. 从共享preferences文件阅读：

    共享preferences preFS = getShared preferences（your_file_name
     MODE_PRIVATE）;串串= prefs.getString（yourStringName
     default_value_here_if_string_is_missing）;
    

您可以使用默认的文件保存/读取preferences。只需更换这两个code段的第一线以上的东西，如：共享preferences preFS = getDefaultShared preferences（getApplicationContext（））;

这就是它！这里检查Android开发专门网页此事，。

希望它是有用的。让我知道这件事情。

How do i retrieve shared preferences that have been saved from a previous activity? Do i need to enable file writing or some other manifest modifications?

解决方案

You don't need any special manifest modificaiton to achieve that.

Assuming you have already saved preferences you can read those preferences at anytime doing something like I show bellow.

1. Write on Shared Preferences file:

     SharedPreferences prefs = getSharedPreferences("your_file_name", MODE_PRIVATE);
     SharedPreferences.Editor editor = prefs.edit();
     editor.putString("yourStringName", "this_is_the_saved_value");
     editor.commit(); // This line is IMPORTANT. If you miss this one its not gonna work!
   

2. Read from Shared Preferences file:

     SharedPreferences prefs = getSharedPreferences("your_file_name",
     MODE_PRIVATE); String string = prefs.getString("yourStringName",
     "default_value_here_if_string_is_missing");
   

You can use a default file to save/ read your preferences. Just replace the first line of the two code snippets above by something like: SharedPreferences prefs = getDefaultSharedPreferences(getApplicationContext());

Thats it! Check the Android Developers dedicated page to this matter, here.

Hope it was usefull. Let me know about it.

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