微调保存在共享片段preferences（OnItemSelectedListener） [英] Save Spinner with SharedPreferences in fragment (OnItemSelectedListener)

问题描述

我是新来的Andr​​oid编程和此刻的我试图做一些纺纱厂有四个数组元素（字符串数组），然后保存共享preferences的当前状态。我已经做了很多研究，但大多数解决方案只对活动的工作，我在一个片段工作。

I am new to Android programming and at the moment I am trying to make some spinners with four array elements (string-array), and then save the current state with shared preferences. I've already done a lot of research, but most of the solutions only work for activities, and I am working in a fragment.

在code现在如下：

FragmentSection3.java

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    View v = inflater.inflate(R.layout.preferences, container, false);

final Spinner spinner2 = (Spinner) v.findViewById(R.id.pref2_spinner);
        ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(
                getActivity(), R.array.spinner_array, android.R.layout.simple_spinner_item);
        adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner2.setAdapter(adapter2);

    spinner2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getActivity().getBaseContext());  //context
            SharedPreferences.Editor prefEditor = prefs.edit();
            prefEditor.putString("savedValue",spinner2.getSelectedItem().toString());
            prefEditor.commit();

            String savedValue=PreferenceManager
                    .getDefaultSharedPreferences(getActivity().getBaseContext()) //context
                    .getString("savedValue","");

            for(int i=0; i<4; i++)
                if(savedValue.equals(spinner2.getItemAtPosition(i).toString())){
                    spinner2.setSelection(i);
                    break;
                }
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent){}
    });

    return v;
 }

我在XML微调

preferences.xml

<Spinner
            android:layout_weight="50"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:id="@+id/pref2_spinner" />

字符串数组

的strings.xml

    <string-array name="spinner_array">
        <item>Keine</item>
        <item>Eher Keine</item>
        <item>Große</item>
        <item>Eher Große</item>
    </string-array>

我不知道为什么我不能挽救我的微调与共享preferences，每次我离开它集一切恢复片段的时间。

I don't know why I can't save my spinner with sharedpreferences, every time I leave the fragment it sets everything back.

推荐答案

您正在保存在正确的地方的价值，但在错误的地方还原它。什么是这样做的目的

You are saving the value at the right place but restoring it at the wrong place. What is the purpose of doing

String savedValue=PreferenceManager
.getDefaultSharedPreferences(getActivity().getBaseContext()) //context
.getString("savedValue",""); 

for(int i=0; i<4; i++)
    if(savedValue.equals(spinner2.getItemAtPosition(i).toString())){
        spinner2.setSelection(i);
        break;
}

在里面OnItemSelectedListener（）？

inside the OnItemSelectedListener() ?

您应该从共享preferences创建视图时恢复值，当一个项目被选中保存。移到高于听者的外code和它应该是工作

You should restore the value from the sharedPreferences when the view is created and save it when an item is selected. Move the code above outside of the listener and it should be working

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