从嵌套的片段将数据发送到父片段 [英] Sending data from nested fragments to parent fragment

问题描述

我有一个片段 FR1 包含多个嵌套 片段; FRA ， FRB ， FRC 。这些嵌套 片段由pressing 按钮更改在 FR1 的布局。每个嵌套 片段的有内他们几个输入字段;其中包括像 EditTexts ， NumberPickers 和纱厂。当我的用户经过和填充的嵌套 片段， FR1 <所有值/ code>（父段）有一个提交按钮。

I have a Fragment FR1 that contains several Nested Fragments; FRa, FRb, FRc. These Nested Fragments are changed by pressing Buttons on FR1's layout. Each of the Nested Fragments have several input fields within them; which include things like EditTexts, NumberPickers, and Spinners. When my user goes through and fills in all the values for the Nested Fragments, FR1 (the parent fragment) has a submit button.

这是我的嵌套 片段我怎么能那么，找回我的价值观并使其 FR1 。

1. 所有浏览的声明和编程每个嵌套 片段。
2. 父片段， FR1 处理嵌套 片段。

1. All Views are declared and programmatically handled within each Nested Fragment.
2. The parent Fragment, FR1 handles the transaction of the Nested Fragments.

我希望这个问题是很清楚，我不知道是否张贴code是必要的，但如果有人认为否则我可以这样做。

I hope this question is clear enough and I am not sure if code is necessary to post but if someone feels otherwise I can do so.

修改1：

下面是如何将我的嵌套 片段：

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();
        }
    });

在我的 constructNewProfile（）方法，从我的嵌套 片段。

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

上面的指父片段的领域;以及它们是如何开始初始化。

The above refers to the fields of the parent fragment; and how they are initially instantiated.

推荐答案

最好的办法是使用一个接口：

The best way is use an interface:

1. 声明在鸟巢片段的接口

1. Declare an interface in the nest fragment

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

将接口父片段

Attach the interface to parent fragment

public void onAttachFragment(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);

    this.mContext = getActivity().getApplicationContext();
    onAttachFragment(getParentFragment());

    // ...
}

通话监听器上按一下按钮。

Call the listener on button click.

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

您的父母片段实现的接口。

Have your parent fragment implement the interface.

 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([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.
           }
      }
 }

添加标签，当你做交易的片段，所以你可以看看它之后调用它的方法。 <一href="http://developer.android.com/reference/android/app/FragmentTransaction.html#add%28int,%20android.app.Fragment,%20java.lang.String%29"相对=nofollow> FragmentTransaction

Add Tag when you do fragment transaction so you can look it up afterward to call its method. FragmentTransaction

这是正确的方式来处理片段和巢片段之间的沟通，这是几乎相同的活动和片段。 http://developer.android.com/guide/components/fragments.html#EventCallbacks

This is the proper way to handle communication between fragment and nest fragment, it's almost the same for activity and fragment. http://developer.android.com/guide/components/fragments.html#EventCallbacks

实际上还有另一位官员的方式，它使用活动的结果，但是这一次是不够好而普遍的。

There is actually another official way, it's using activity result, but this one is good enough and common.

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