将嵌套片段中的数据发送到父片段

Question

我有一个Fragment FR1包含几个Nested Fragments; FRa,FRb,FRc.这些Nested Fragments都是按改变Buttons上FR1的布局.每个Nested Fragments都有几个输入字段; 其中包括像EditTexts,NumberPickers和Spinners.当我的用户经历并填写所有值时Nested Fragments,FR1(父片段)有一个提交按钮.

那么我怎样才能从我的Nested Fragments身上找回我的价值并将其带入FR1.

1. 所有Views都在每个中声明并以编程方式处理Nested Fragment.
2. 父母Fragment,FR1处理交易Nested Fragments.

我希望这个问题足够清楚,我不确定是否需要发布代码,但如果有人不这样认为我可以这样做.

编辑1:

这是我添加我的方式Nested Fragments:

tempRangeButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {

            getChildFragmentManager().beginTransaction()
                    .add(R.id.settings_fragment_tertiary_nest, tempFrag)
                    .commit();

        }
    });

    scheduleButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {

            getChildFragmentManager().beginTransaction()
                    .add(R.id.settings_fragment_tertiary_nest, scheduleFrag)
                    .commit();
        }
    });

    alertsButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {

            getChildFragmentManager().beginTransaction()
                    .add(R.id.settings_fragment_tertiary_nest, alertsFrag)
                    .commit();

        }
    });

    submitProfile.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            constructNewProfile();
        }
    });

我的constructNewProfile()方法需要我的值Nested Fragments.

public Fragment tempFrag = fragment_profile_settings_temperature
        .newInstance();
public Fragment scheduleFrag= fragment_profile_settings_schedules
            .newInstance();
public Fragment alertsFrag = fragment_profile_settings_alerts
        .newInstance();

以上是指父片段的字段; 以及它们最初是如何实例化的.

Answer 1

最好的方法是使用界面:

1. 在nest片段中声明一个接口

   // Container Activity or Fragment must implement this interface
   public interface OnPlayerSelectionSetListener
   {
       public void onPlayerSelectionSet(List<Player> players_ist);
   }
   

2. 将接口附加到父片段

   // In the child fragment.
   public void onAttachToParentFragment(Fragment fragment)
   {
       try
       {
           mOnPlayerSelectionSetListener = (OnPlayerSelectionSetListener)fragment;
   
       }
       catch (ClassCastException e)
       {
             throw new ClassCastException(
                 fragment.toString() + " must implement OnPlayerSelectionSetListener");
       }
   }
   
   
   @Override
   public void onCreate(Bundle savedInstanceState)
   {
       Log.i(TAG, "onCreate");
       super.onCreate(savedInstanceState);
   
       onAttachToParentFragment(getParentFragment());
   
       // ...
   }
   

3. 按下按钮调用监听器.

   // In the child fragment.
   @Override
   public void onClick(View v)
   {
       switch (v.getId())
       {
           case R.id.tv_submit:
               if (mOnPlayerSelectionSetListener != null)
               {                
                    mOnPlayerSelectionSetListener.onPlayerSelectionSet(selectedPlayers);
               }
               break;
           }
       }
   

4. 让您的父片段实现接口.

    public class Fragment_Parent extends Fragment implements Nested_Fragment.OnPlayerSelectionSetListener
    {
         // ...
         @Override
         public void onPlayerSelectionSet(final List<Player> players_list)
         {
              FragmentManager fragmentManager = getChildFragmentManager();
              SomeOtherNestFrag someOtherNestFrag = (SomeOtherNestFrag)fragmentManager.findFragmentByTag("Some fragment tag");
              //Tag of your fragment which you should use when you add
   
              if(someOtherNestFrag != null)
              {
                   // your some other frag need to provide some data back based on views.
                   SomeData somedata = someOtherNestFrag.getSomeData();
                   // it can be a string, or int, or some custom java object.
              }
         }
    }
   

在对事务进行分段时添加标记,以便以后可以查找它以调用其方法.FragmentTransaction

这是处理片段和嵌套片段之间通信的正确方法,它对于活动和片段几乎相同. http://developer.android.com/guide/components/fragments.html#EventCallbacks

实际上还有另一种官方方式,即使用活动结果,但这个方法足够好且很常见.

Answer 2

您可以通过以下方式调用子片段,而不是使用接口:

( (YourFragmentName) getParentFragment() ).yourMethodName();