Question

对不起，我想试试android开发者的Android教程。在Show Friends部分。我已成功完成了步骤hello Scrumptious，Autenticate with login和personalize部分。在Show Friends部分，我收到错误

方法getRequestCode（）未定义类型 SelectionFragment

之前我使用过API级别17。然后尝试更改为API级别10，我收到很多错误。然后我更改为API级别8，然后出现上一个错误。 getRequestCode（）方法仍无效。

你能帮我解决任何线索错误吗？我试着在网上搜索，但是，我真的不知道是什么问题。我尝试重新阅读教程，制作新项目，然后尝试多次仍然失败。

请帮忙。

谢谢。

package com.firstfbapp;

import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import com.facebook.Request;
import com.facebook.Response;
import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.model.GraphUser;
import com.facebook.widget.ProfilePictureView;

public class SelectionFragment extends Fragment {
    private static final String TAG = "SelectionFragment";
    private ProfilePictureView profilePictureView;
    private TextView userNameView;
    private UiLifecycleHelper uiHelper;
    private ListView listView;
    private List<BaseListElement> listElements;
    private Session.StatusCallback callback = new Session.StatusCallback() {
        @Override
        public void call(final Session session, final SessionState state,
                final Exception exception) {
            onSessionStateChange(session, state, exception);
        }
    };
    private static final int REAUTH_ACTIVITY_CODE = 100;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        uiHelper = new UiLifecycleHelper(getActivity(), callback);
        uiHelper.onCreate(savedInstanceState);
    }

    public void onClick(View view) {
        // Do nothing for now
        startPickerActivity(PickerActivity.FRIEND_PICKER, getRequestCode());
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REAUTH_ACTIVITY_CODE) {
            uiHelper.onActivityResult(requestCode, resultCode, data);
        } else if (resultCode == Activity.RESULT_OK) {
            // Do nothing for now
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        super.onCreateView(inflater, container, savedInstanceState);
        View view = inflater.inflate(R.layout.selection, container, false);
        // Check for an open session
        Session session = Session.getActiveSession();
        if (session != null && session.isOpened()) {
            // Get the user's data
            makeMeRequest(session);
        }
        // Find the user's profile picture custom view
        profilePictureView = (ProfilePictureView) view
                .findViewById(R.id.selection_profile_pic);
        profilePictureView.setCropped(true);

        // Find the user's name view
        userNameView = (TextView) view.findViewById(R.id.selection_user_name);
        // Find the list view
        listView = (ListView) view.findViewById(R.id.selection_list);

        // Set up the list view items, based on a list of
        // BaseListElement items
        listElements = new ArrayList<BaseListElement>();
        // Add an item for the friend picker
        listElements.add(new PeopleListElement(0));
        // Set the list view adapter
        listView.setAdapter(new ActionListAdapter(getActivity(),
                R.id.selection_list, listElements));

        return view;
    }

    private void startPickerActivity(Uri data, int requestCode) {
        Intent intent = new Intent();
        intent.setData(data);
        intent.setClass(getActivity(), PickerActivity.class);
        startActivityForResult(intent, requestCode);
    }

    @Override
    public void onResume() {
        super.onResume();
        uiHelper.onResume();
    }

    @Override
    public void onSaveInstanceState(Bundle bundle) {
        super.onSaveInstanceState(bundle);
        uiHelper.onSaveInstanceState(bundle);
    }

    @Override
    public void onPause() {
        super.onPause();
        uiHelper.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        uiHelper.onDestroy();
    }

    private void makeMeRequest(final Session session) {
        // Make an API call to get user data and define a
        // new callback to handle the response.
        Request request = Request.newMeRequest(session,
                new Request.GraphUserCallback() {
                    @Override
                    public void onCompleted(GraphUser user, Response response) {
                        // If the response is successful
                        if (session == Session.getActiveSession()) {
                            if (user != null) {
                                // Set the id for the ProfilePictureView
                                // view that in turn displays the profile
                                // picture.
                                profilePictureView.setProfileId(user.getId());
                                // Set the Textview's text to the user's name.
                                userNameView.setText(user.getName());
                            }
                        }
                        if (response.getError() != null) {
                            // Handle errors, will do so later.
                        }
                    }
                });
        request.executeAsync();
    }

    private void onSessionStateChange(final Session session,
            SessionState state, Exception exception) {
        if (session != null && session.isOpened()) {
            // Get the user's data.
            makeMeRequest(session);
        }
    }

    private class ActionListAdapter extends ArrayAdapter<BaseListElement> {
        private List<BaseListElement> listElements;

        public ActionListAdapter(Context context, int resourceId,
                List<BaseListElement> listElements) {
            super(context, resourceId, listElements);
            this.listElements = listElements;
            // Set up as an observer for list item changes to
            // refresh the view.
            for (int i = 0; i < listElements.size(); i++) {
                listElements.get(i).setAdapter(this);
            }
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view = convertView;
            if (view == null) {
                LayoutInflater inflater = (LayoutInflater) getActivity()
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                view = inflater.inflate(R.layout.listitem, null);
            }

            BaseListElement listElement = listElements.get(position);
            if (listElement != null) {
                view.setOnClickListener(listElement.getOnClickListener());
                ImageView icon = (ImageView) view.findViewById(R.id.icon);
                TextView text1 = (TextView) view.findViewById(R.id.text1);
                TextView text2 = (TextView) view.findViewById(R.id.text2);
                if (icon != null) {
                    icon.setImageDrawable(listElement.getIcon());
                }
                if (text1 != null) {
                    text1.setText(listElement.getText1());
                }
                if (text2 != null) {
                    text2.setText(listElement.getText2());
                }
            }
            return view;
        }

    }

    private class PeopleListElement extends BaseListElement {

        public PeopleListElement(int requestCode) {
            super(getActivity().getResources().getDrawable(
                    R.drawable.action_people), getActivity().getResources()
                    .getString(R.string.action_people), getActivity()
                    .getResources().getString(R.string.action_people_default),
                    requestCode);
        }

        @Override
        protected View.OnClickListener getOnClickListener() {
            return new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    // Do nothing for now
                }
            };
        }
    }
}

Answer 1

从我看到的内容，您必须扩展FragmentActivity而不是Fragment，如教程中所述：“首先，在您的包中创建一个名为''PickerActivity''的新类，子类FragmentActivity。“
其次，您拨打片段的getRequestCode()中的onClick，而不是PeopleListElement中的{{1}}。

Answer 2

我将PeopleListElement修改为以下

private class PeopleListElement extends BaseListElement {
    private int requestCode;
    public PeopleListElement(int requestCode) {
        super(getActivity().getResources().getDrawable(R.drawable.action_people),
                getActivity().getResources().getString(R.string.action_people),
                getActivity().getResources().getString(R.string.action_people_default),
                requestCode);
        this.requestCode = requestCode;
    }

    @Override
    protected View.OnClickListener getOnClickListener() {
        return new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startPickerActivity(PickerActivity.FRIEND_PICKER, requestCode);
            }
        };
    }
}

我在PeopleListElement中声明了一个名为“requestCode”的变量。每当调用PeopleListElement的构造函数时，都会为此变量赋值。然后我用“requestCode”替换getRequestCode（）。

对于SelectionFragment类型，方法getRequestCode（）未定义

2 个答案: