共享首选项始终返回默认值 [英] Shared Preference returns always the default value

问题描述

这是我用来在 Preference 中创建和存储值的代码.传出是字符串变量.

Here is code I am Using to create and store value in Preference. outgoing is String variable.

SharedPreferences sp = getSharedPreferences(outgoing, Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();                
editor.putString("PhoneNo","Hi");
editor.commit();

这是从 SharedPreference 获取值的代码.

Here is the code to get value from SharedPreference.

SharedPreferences sp 
=getSharedPreferences(outgoing,Activity.MODE_PRIVATE);
String calln = sp.getString("PhoneNo","0");
Toast.makeText(mContext, "SHARED"+calln,Toast.LENGTH_LONG).show();

推荐答案

您可能应该在访问它们的上下文中调用 getSharedPreferences.

You should probably call the getSharedPreferences on the context from which you are accessing them.

来源

因此，根据您访问上下文的方式，如果您将其传递给其他活动或异步任务，以下是一些用法示例:

Therefore, depending on how you can access your context, if you pass it to some other activity or in an asynchronous task, here are some examples of usage:

this.getSharedPreferences(outgoing, Activity.MODE_PRIVATE);

context.getSharedPreferences(outgoing, Activity.MODE_PRIVATE);

getApplicationContext().getSharedPreferences(outgoing, Activity.MODE_PRIVATE);

此外，一种测试内容的方法是在 SharedPreferences 更改时使用侦听器:

Also, one way you can test your stuff is to use a listener when SharedPreferences get changed:

onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)

Called when a shared preference is changed, added, or removed.

这是如何做到的

您也可以使用Preference Manager 来获取SharedPreferences:

You can also use the Preference Manager to obtain the SharedPreferences:

PreferenceManager.getSharedPreferences(YOUR_CONTEXT).getString(
                    "PhoneNo", "0");

或者存储它们:

PreferenceManager.getSharedPreferences(YOUR_CONTEXT).edit().putString(
                    "PhoneNo", "Hi").commit();

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