java为什么我对Facebook Graph API的调用没有显示任何内容？

Question

好的，我正在编辑这篇文章，用我在过去几个小时里添加的一些新代码来包括整个课程。基本上，我想用表示Facebook用户签入的标记填充谷歌地图。不幸的是，我的代码一直不配合——我试图查看Facebook提供的文档，并在网上搜索答案，但没有找到任何有用的东西。到目前为止，我所能做的只是在Facebook上验证应用程序的权限并显示地图，尽管我已经测试了在早期版本的应用程序中添加带有虚拟值的标记的能力，而且效果很好

我之前的问题是为什么我对Graph API的调用没有显示任何内容——我进行了与AuthorizeListener子类中列出的相同的调用，但只是试图在日志条目中输出原始JSON字符串，而不是对其进行操作。我认为无论是什么原因导致了这个问题，都可能是我目前问题的原因

无论如何，我如何让我的应用程序显示用户已登录位置的标记？我认为我的代码让我有了一个很好的开始，但我的子类中显然存在一些问题。你们怎么看

public class FBCTActivity extends MapActivity {
public static Context mContext;
List<Overlay> mapOverlays;
FBCTMarkerOverlay markerLayer;
ArrayList<OverlayItem> overlays = new ArrayList<OverlayItem>();

// Facebook Application ID
private static final String APP_ID = "";

Facebook mFacebook = new Facebook(APP_ID);

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mContext = this;
    setContentView(R.layout.main);

    // Set up Facebook stuff
    mFacebook.authorize(this, new String[]{"user_checkins", "offline_access"}, new AuthorizeListener());

    // Set up map stuff
    MapView mMapView = (MapView)findViewById(R.id.map);
    mMapView.setSatellite(true);
    MapController mMapController = mMapView.getController();
    mMapController.animateTo(getCurrentLocation());
    mMapController.setZoom(3);

    // Set up overlay stuff
    mapOverlays = mMapView.getOverlays();
    Drawable drawable = this.getResources().getDrawable(R.drawable.icon);
    markerLayer = new FBCTMarkerOverlay(drawable);

    // markerLayer is populated in the AuthorizeListener sub-class
    mapOverlays.add(markerLayer);

}

/**
 * Determines the device's current location, but does not display it.
 * Used for centering the view on the device's location.
 * @return A GeoPoint object that contains the lat/long coordinates for the device's location.
 */
private GeoPoint getCurrentLocation() {
    LocationManager mLocationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
    Criteria mCriteria = new Criteria();
    mCriteria.setAccuracy(Criteria.ACCURACY_COARSE);
    mCriteria.setPowerRequirement(Criteria.POWER_LOW);
    String mLocationProvider = mLocationManager.getBestProvider(mCriteria, true);
    Location mLocation = mLocationManager.getLastKnownLocation(mLocationProvider);

    int mLat = (int)(mLocation.getLatitude()*1E6);
    int mLong = (int)(mLocation.getLongitude()*1E6);
    return new GeoPoint(mLat, mLong);
}

@Override
protected boolean isRouteDisplayed() {
    // TODO Auto-generated method stub
    return false;
}

private class AuthorizeListener implements DialogListener {
    public void onComplete(Bundle values) {
        new Thread() {
            @Override
            public void run() {
                try {
                    String response = mFacebook.request("me/checkins"); // The JSON to get
                                            JSONObject jObject = Util.parseJson(response);
                    JSONArray jArray = jObject.getJSONArray("data"); // Read the JSON array returned by the request
                    for (int i = 0; i < jArray.length(); i++) { // Iterate through the array
                        JSONObject outerPlace = jArray.getJSONObject(i); // The outer JSON object
                        JSONObject place = outerPlace.getJSONObject("place"); // Second-tier JSON object that contains id, name, and location values for the "place"
                        String placeName = place.getString("name"); // The place's name
                        JSONObject placeLocation = place.getJSONObject("location"); // Third-tier JSON object that contains latitude and longitude coordinates for the place's "location"
                        int lat = (int) (placeLocation.getDouble("latitude")*1E6); // The place's latitude
                        int lon = (int) (placeLocation.getDouble("longitude")*1E6); // The place's longitude
                        String date = outerPlace.getString("created_time"); // Timestamp of the checkin
                        overlays.add(new OverlayItem(new GeoPoint(lat, lon), placeName, "Checked in on: " + date)); // Add the place's details to our ArrayList of OverlayItems
                    }
                    mFacebook.logout(mContext); // Logout of Facebook
                    for (int i = 0; i < overlays.size(); i++) {
                        markerLayer.addOverlayItem(overlays.get(i));
                    }
                } catch(IOException e) {
                    Log.v("FBCTActivity", e.getMessage());
                } catch(JSONException e) {
                    Log.v("FBCTActivity", e.getMessage());
                }
            }
        }.start();
    }

    public void onFacebookError(FacebookError e) {
        Log.w("FBCTActivity", e.getMessage());
        // TODO: Add more graceful error handling
    }

    public void onError(DialogError e) {
        Log.w("FBCTActivity", e.getMessage());
    }

    public void onCancel() {
        // TODO Auto-generated method stub

    }
}

}

Answer 1

这可能不是原因，但您尚未定义应用程序ID：

private static final String APP_ID = "";

此外，还必须在调用mFacebook的活动中重写onActivityResult。授权，所以将此添加到您的代码中：

    @Override
protected void onActivityResult(int requestCode, int resultCode,
                                Intent data) {
    mFacebook.authorizeCallback(requestCode, resultCode, data);
}

如果不这样做，你的应用程序将无法获取图形的令牌，你的连接将返回JSON错误消息