我一直在使用Android支持库中包含的新的嵌套片段API。
嵌套片段所面临的问题是，如果调用了一个嵌套片段（即，已通过的FragmentManagerreturn由添加到另一个片段的片段getChildFragmentManager()）startActivityForResult()，onActivityResult()则不会调用该嵌套片段的方法。但是，父片段onActivityResult()和活动onActivityResult()都被调用。
我不知道是否缺少有关嵌套片段的信息，但是我没有想到所描述的行为。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>