Question

我的MainActivity包含一个由两个选项卡组成的片段，每个选项卡中有一个片段（ChatListFragment和FriendListFragment）。每个片段都有ListView。当用户点击ListView的每一行时，将显示ChatActivity。

我希望ChatListFragment中的ListView（使用ListAdapter作为调用ChatActivity的适配器）在ChatActivity关闭后更新其ListView。我在我的代码中尝试了onActivityResult方法，如下所示，但requestCode始终为-1。

MainActivity.java

public class MainActivity extends AppCompatActivity {

    ...

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Log.d(TAG, "onActivityResult: " + " " + requestCode + " == " + MYACTIVITY_REQUEST_CODE + " and " + resultCode + " == " + Activity.RESULT_OK);
        Log.d(TAG, "onActivityResult: " + MainActivity.class.getSimpleName());

        for (Fragment fragment : getSupportFragmentManager().getFragments()) {
            fragment.onActivityResult(requestCode, resultCode, data);
        }
    }

    ...
}

ChatListFragment.java

public class ChatListFragment extends Fragment {

    ...

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Log.d(TAG, "onActivityResult: " + TAG);
        Log.d(TAG, "onActivityResult: " + " " + requestCode + " == " + MYACTIVITY_REQUEST_CODE + " and " + resultCode + " == " + Activity.RESULT_OK);
        if ((requestCode == MYACTIVITY_REQUEST_CODE) && (resultCode == Activity.RESULT_CANCELED)) {
            List<Friend> friendList = getFriendChatList();
            adapter = new ListAdapter(getActivity(), R.layout.fragment_list, friendList, true);
            adapter.notifyDataSetChanged();
            listView.setAdapter(adapter);
            Log.d(TAG, "onActivityResult number of friend chats: " + getFriendChatList().size());
            if(friendList.isEmpty()) {
                linearLayout.setVisibility(View.VISIBLE);
            } else {
                linearLayout.setVisibility(View.GONE);
            }
        }
    }
}

ChatActivity.java

public class ChatActivity extends AppCompatActivity {

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ...

        if (getParent() == null) {
            setResult(Activity.RESULT_OK);
        } else {
            getParent().setResult(Activity.RESULT_OK);
        }
    }

    ...
}

ListAdapter.java

public class ListAdapter extends ArrayAdapter<Friend> {

   private static final int MYACTIVITY_REQUEST_CODE = 9000;

   public ListAdapter(Context context, int resource, List<Friend> objects, boolean isChat) {
        super(context, resource, objects);
        this.context = context;
    }

    @Override
    public View getView(final int position, final View convertView, ViewGroup parent) {
        View view = convertView;
        LayoutInflater layoutInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if(null == view) {
            view = layoutInflater.inflate(R.layout.list_friend, null);
        }

        final Friend friend = friendList.get(position);

        if(null != friend) {
            final CardView rowLayout = (CardView) view.findViewById(R.id.row_layout);
            final ImageView friendImage = (ImageView) view.findViewById(R.id.list_friend_image);
            final TextView friendName = (TextView) view.findViewById(R.id.list_friend_name);
            final TextView friendDescription = (TextView) view.findViewById(R.id.list_friend_description);
            final TextView friendLastChatTime = (TextView) view.findViewById(R.id.list_friend_lastChatTime);

            // Open chat activity
            rowLayout.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent intent = new Intent(context, ChatActivity.class);
                    intent.putExtra(KEY_FRIEND_NAME, friend.getName());
                    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    ((Activity) context).startActivityForResult(intent, MYACTIVITY_REQUEST_CODE);
                }
            });
        }

        return view;
    }
}

Answer 1

您需要创建一个Intent，然后将Result设置为该Intent。

在ChatActivity

中尝试这样的操作

Intent intent=new Intent();

if (getParent() == null) {
            setResult(Activity.RESULT_OK,intent);
        } else {
            getParent().setResult(Activity.RESULT_OK,intent);
        }

      finish();

设置结果后，您还需要finish您的ChatActivity。像这样：

我不明白，这就是为什么你需要检查父母班级。你总是可以这样做

Intent intent= new Intent();
setResult(RESULT_OK,intent);
finish();

这应该正常工作。

希望这会有所帮助：）

Answer 2

我知道这真的很晚！但是，onActivityResult将不会获得您在setResult()中设置的结果！因为您在Intent.FLAG_ACTIVITY_NEW_TASK

中设置了rowLayout.setOnClickListener

基于reference

当呼叫者从以下位置请求结果时，不能使用此标志正在启动的活动。

因此，首先删除intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 然后setResult(RESULT_OK,intent);放在适当的位置

在这种情况下，您将获得在onActivityResult

中设置的响应。

onActivityResult requestCode返回0

2 个答案: