java - onActivityResult() 未在新的嵌套 fragment API 中调用

Question

我一直在使用新的nested fragment Android 包含在支持库中的 API。

我面临的嵌套 fragment 的问题是，如果嵌套 fragment (即通过 getChildFragmentManager() 返回的 FragmentManager 添加到另一个 fragment 的 fragment ) 调用startActivityForResult()，嵌套 fragment 的onActivityResult() 方法没有被调用。但是，父 fragment 的 onActivityResult() 和 Activity 的 onActivityResult() 都会被调用。

我不知道我是否遗漏了有关嵌套 fragment 的某些内容，但我没想到所描述的行为。下面是重现此问题的代码。如果有人能指出我正确的方向并向我解释我做错了什么，我将不胜感激:

package com.example.nestedfragmentactivityresult;

import android.media.RingtoneManager;
import android.os.Bundle;
import android.content.Intent;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends FragmentActivity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        this.getSupportFragmentManager()
            .beginTransaction()
            .add(android.R.id.content, new ContainerFragment())
            .commit();
    }

    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data);

        // This is called
        Toast.makeText(getApplication(),
            "Consumed by activity",
            Toast.LENGTH_SHORT).show();
    }

    public static class ContainerFragment extends Fragment
    {
        public final View onCreateView(LayoutInflater inflater,
                                       ViewGroup container,
                                       Bundle savedInstanceState)
        {
            View result = inflater.inflate(R.layout.test_nested_fragment_container,
                container,
                false);

            return result;
        }

        public void onActivityCreated(Bundle savedInstanceState)
        {
            super.onActivityCreated(savedInstanceState);
            getChildFragmentManager().beginTransaction()
                .add(R.id.content, new NestedFragment())
                .commit();
        }

        public void onActivityResult(int requestCode,
                                     int resultCode,
                                     Intent data)
        {
            super.onActivityResult(requestCode, resultCode, data);

            // This is called
            Toast.makeText(getActivity(),
                "Consumed by parent fragment",
                Toast.LENGTH_SHORT).show();
        }
    }

    public static class NestedFragment extends Fragment
    {
        public final View onCreateView(LayoutInflater inflater,
                                       ViewGroup container,
                                       Bundle savedInstanceState)
        {
            Button button = new Button(getActivity());
            button.setText("Click me!");
            button.setOnClickListener(new View.OnClickListener()
            {
                public void onClick(View v)
                {
                    Intent intent = new Intent(RingtoneManager.ACTION_RINGTONE_PICKER);
                    startActivityForResult(intent, 0);
                }
            });

            return button;
        }

        public void onActivityResult(int requestCode,
                                     int resultCode,
                                     Intent data)
        {
            super.onActivityResult(requestCode, resultCode, data);

            // This is NOT called
            Toast.makeText(getActivity(),
                "Consumed by nested fragment",
                Toast.LENGTH_SHORT).show();
        }
    }
}

test_nested_fragment_container.xml 是:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/content"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

</FrameLayout>

Answer 1

我用以下代码解决了这个问题(使用了支持库):

在容器 fragment 中以这种方式覆盖onActivityResult:

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        List<Fragment> fragments = getChildFragmentManager().getFragments();
        if (fragments != null) {
            for (Fragment fragment : fragments) {
                fragment.onActivityResult(requestCode, resultCode, data);
            }
        }
    }

现在嵌套 fragment 将接收到 onActivityResult 方法的调用。

另外，如 noted Eric Brynsvold在类似的问题中，嵌套 fragment 应该使用它的父 fragment 而不是简单的 startActivityForResult() 调用来启动 Activity 。因此，在嵌套 fragment 开始 Activity 中:

getParentFragment().startActivityForResult(intent, requestCode);