使用内部类的共享preferences [英] Use sharedpreferences inside class

问题描述

我使用的是类中我的共享preferences有问题。我的code和程序流程：

I am having a problem using my shared preferences inside a class. My code and program flow:

我有一个微调里面我activity.I我实现我自己的OnItemSelectedListener是这样的：

I have a Spinner inside my activity.I am implementing my own OnItemSelectedListener like this:

MyOnItemSelectedListener.java

public class MyOnItemSelectedListener implements OnItemSelectedListener  {
     SharedPreferences pref;
     Editor editor;

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        //parent.setSelection(7);
        Toast.makeText(parent.getContext(), "Selected Country : " + parent.getItemIdAtPosition(pos), Toast.LENGTH_SHORT).show();
    }
    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }
}

我把上面的类从我的活动是这样的：

I call the above class from my activity like this:

spinner1 = (Spinner) findViewById(R.id.spinner1);
spinner1.setOnItemSelectedListener(new MyOnItemSelectedListener());

到目前为止good.What我要的是节省 spinner1 所选项目到用户的preferences（从保存的值设置）。

So far so good.What i want is to save the selected item on spinner1 to the user's preferences(and set it from saved value).

一个活动里面我用我的共享preFS是这样的：

Inside an activity i am using my shared prefs like this:

preF = getApplicationContext（）getShared preferences（我的preF，0）;

但上下文不存在在类中！任何帮助检索/保存preF当用户选择的微调中的项目？

but inside the class the context doesn't exists! Any help retrieving/saving pref when the user selects an item on the spinner?

感谢您！

推荐答案

为您的听众一个构造函数和传递上下文来的：

Create a constructor for your listener and pass a Context to it:

public class MyOnItemSelectedListener implements OnItemSelectedListener  {
    SharedPreferences pref;
    Editor editor;

    public MyOnItemSelectedListener(Context context) {
        pref = context.getSharedPreferences("MyPref", 0);
    }

    // rest of your code
}

这篇关于使用内部类的共享preferences的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！