ArrayAdapter中的createFromResources（）不能應用於微調器

Question

Im在我的微調器上創建ArrayAdapter時遇到麻煩。我不知道如何向大家解釋，但人們說一張圖片可以說1000字。所以我提供了我的問題的照片。請幫助我，我真的不知道該怎麼做才知道。

這是我的課

public class SettingFragment extends Fragment{ 

private View rootView; 
Spinner spinner; 
ArrayAdapter<CharSequence> adapter; 

public SettingFragment(){ 
    //required empty public constructor 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    rootView = inflater.inflate(R.layout.fragment_setting, container, false); 

    spinner = (Spinner)rootView.findViewById(R.id.spinner); 
    adapter = ArrayAdapter.createFromResource(this, R.array.select_font_size, android.R.layout.simple_spinner_item); 
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    spinner.setAdapter(adapter); 

    return rootView; 
} 

}

這是我string.xml

<string-array name="select_font_size"> 
    <item>Small</item> 
    <item>Default</item> 
    <item>Large</item> 
    <item>Larger</item> 
</string-array> 

，這是我的XML代碼

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" android:layout_width="match_parent" 
android:layout_height="match_parent"> 


<Spinner 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/spinner" 
    android:layout_gravity="center_horizontal" /> 

Answer 1

我建議移動適配器的創建onActivityCreated回調內部時，你肯定知道通過調用getActivity()你會得到活動的不空實例：

public class SettingFragment extends Fragment{ 

private View rootView; 
Spinner spinner; 
ArrayAdapter<CharSequence> adapter; 

public SettingFragment(){ 
    //required empty public constructor 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    rootView = inflater.inflate(R.layout.fragment_setting, container, false); 
    spinner = (Spinner)rootView.findViewById(R.id.spinner); 

    return rootView; 
} 

@Override 
public void onActivityCreated(@Nullable Bundle savedInstanceState) { 
    super.onActivityCreated(savedInstanceState); 
    adapter = ArrayAdapter.createFromResource(getActivity(), R.array.select_font_size, android.R.layout.simple_spinner_item); 
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
      spinner.setAdapter(adapter); 
    } 
} 

Answer 2

嘗試使用應用程序上下文或實例化片段的活動的上下文。

adapter = ArrayAdapter.createFromResource(getApplicationContext(), R.array.select_font_size, android.R.layout.simple_spinner_item); 

OR

adapter = ArrayAdapter.createFromResource(YOUR_ACTIVITY_CONTEXT_TO_BE_PASSED_INTO_FRAGMENT, R.array.select_font_size, android.R.layout.simple_spinner_item);