Android片段：如何通过片段控件循环

Question

如何使我的片段中的所有Spinners都可以聚焦？

设置android:focusableInTouchMode和android:focusable在我的布局的XML是没有效果的。

更一般地说，我无法循环浏览我的Fragment控件并找到特定类型的所有控件，例如所有Spinners或所有EditTexts。

Answer 1

这对我来说非常棘手，所以我想我会在这里发布我的解决方案。这解决了一个特别的问题（如何使纺纱厂可调焦），而且还解决了更一般的问题（如何通过控制回路中的片段。

public class MyFragment extends Fragment { 

    private static ArrayList<Spinner> spinners = new ArrayList<Spinner>(); 


    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 

     // inflate the layout 
     View layout = inflater.inflate(R.layout.my_fragment_xml, container, false); 

     // cast our newly inflated layout to a ViewGroup so we can 
     // enable looping through its children 
     set_spinners((ViewGroup)layout); 

     // now we can make them focusable 
     make_spinners_focusable(); 

     return layout; 
    } 

    //find all spinners and add them to our static array 

    private void set_spinners(ViewGroup container) { 
     int count = container.getChildCount(); 
     for (int i = 0; i < count; i++) { 
      View v = container.getChildAt(i); 
      if (v instanceof Spinner) { 
       spinners.add((Spinner) v); 
      } else if (v instanceof ViewGroup) { 
       //recurse through children 
       set_spinners((ViewGroup) v); 
      } 
     } 
    } 

    //make all spinners in this fragment focusable 
    //we are forced to do this in code 

    private void make_spinners_focusable() {    
     for (Spinner s : spinners) { 
      s.setFocusable(true); 
      s.setFocusableInTouchMode(true); 
      s.setOnFocusChangeListener(new View.OnFocusChangeListener() { 
       @Override 
       public void onFocusChange(View v, boolean hasFocus) { 
        if (hasFocus) { 
         v.performClick(); 
        } 
       } 
      }); 
     } 
    } 


} 

Answer 2

与set_spinners()所选择的答案，如果有嵌套布局中不起作用。活动getChildCount()只给出了第一级的孩子的最好使用getAllChildrenBFS从这个answer：

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