Question

我在活动中的片段中有一个列表，该列表会启动详细信息，其中包含一个包含所选对象信息的片段。

如果选择了其中一个操作项，则活动结果为OK，如果再次选中，则结果将切换回CANCELED。我只想在用户导航回列表时传递此结果。我已经消除了几个问题，并且我到达了listfragment中的onActivityResult函数，但结果代码不是我传递的那个。在调试时，我还注意到listactivity中的onActivityResult函数永远不会被触发。

ListActivity：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    Log.i("LA", "onActivityResult: " + resultCode);
    super.onActivityResult(requestCode, resultCode, data);
}

ListFragment：

/**
 * Launch detail activity
 */
public class OnObjectClickListener implements OnItemClickListener {

    public OnObjectClickListener() {
        super();
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Log.i("OnObjectClickListener", "Selected an object");
        ObjectAdapter adapter = (ObjectAdapter) _objList.getAdapter();
        Object o = adapter.getItem(position);

        Intent i = new Intent(adapter.getContext(), DetailActivity.class);
        i.putExtra(DetailActivity.ARG_OBJCODE, o.getCode());
        startActivityForResult(i, DetailActivity.ARG_FOLLOW_OBJ_CHANGE);
    }
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    Log.i("LF", "Activity result received");
    if (requestCode == DetailActivity.ARG_FOLLOW_OBJ_CHANGE
        && resultCode == Activity.RESULT_OK
        && data != null
        && data.hasExtra(DetailActivity.ARG_OBJCODE)){
        // Update object in the list: following indicator has changed
        String objcode = data.getStringExtra(DetailActivity.ARG_OBJCODE);
        ObjectAdapter oa = (ObjectAdapter) _objList.getAdapter();
        for (Object o : oa.getObjects()){
            // Toggle following state in the game
            if (o.getCode().equals(objcode)){
                o.setFollowing(!o.isFollowing());
                oa.notifyDataSetChanged();
                Log.i("LF", "Edited dataset");
                break;
            }
        }
        Log.i("LF", "Result processed");
    } else {
        super.onActivityResult(requestCode, resultCode, data);
        Log.i("LF", "Result not recognized");
    }
}

行动项详细活动：

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    DetailFragment df = (DetailFragment) getFragmentManager().findFragmentByTag(_objCode);

    switch (item.getItemId()) {
    case android.R.id.home:
        NavUtils.navigateUpFromSameTask(this);
        return true;
    case R.id.action_follow_obj:
        if (df != null){
            df.followObj(true);
            configResult();
        }
        break;
    case R.id.action_unfollow_obj:
        if (df != null){
            df.followObj(false);
            configResult();
        }
        break;
    }
    return super.onOptionsItemSelected(item);
}
/** Sets the result of this activity (did the following parameter change, or not?)
 * @return nothing */
private void configResult() {
    // switch follow state monitor: statechange is true upon uneven changes
    // meaning the state is not really changed if the game is first followed and subsequently unfollowed
    _followStateChanged = !_followStateChanged;
    Log.i("DA", "State changed: " + _followStateChanged);
}

这就是我尝试将结果返回到上一个listfragment的方式：

@Override
public void onBackPressed() {
    super.onBackPressed();

    // config result
    Intent i = new Intent();
    i.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
    i.putExtra(DetailActivity.ARG_OBJCODE, _objCode);
    int result = _followStateChanged ? Activity.RESULT_OK : Activity.RESULT_CANCELED;
    if (getParent() == null){
        setResult(result, i);
    } else {
        getParent().setResult(result, i);
    }
    this.finish();
    Log.i("DA", "Back pressed, intent passed and set as a result");
}

... getParent（）始终为null

resultCode总是0，有没有人知道我哪里出错了？我已经咨询了这些答案，应用并测试了它们，得到了进一步但尚无解决方案：

Answer 1

**我也遇到了同样的问题OnActivityResult（）你必须改变你的实现bc包含Fragment，Host Activity的OnActivityResult（）被调用而不是片段的**

Answer 2

你应该在方法结束时调用super。不是开始。

@Override 
public void onBackPressed() {

    // config result 
    Intent i = new Intent();
    i.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
    i.putExtra(DetailActivity.ARG_OBJCODE, _objCode);
    int result = _followStateChanged ? Activity.RESULT_OK : Activity.RESULT_CANCELED;
    if (getParent() == null){
        setResult(result, i);
    } else { 
        getParent().setResult(result, i);
    } 
    this.finish();
    Log.i("DA", "Back pressed, intent passed and set as a result");

    super.onBackPressed(); 
}

片段在onActivityResult中没有收到正确的结果

2 个答案: