java - 将字符串从 Activity 传递到 Fragment

Question

我的 Activty 代码 fragment 实现了 GooglePlayServicesClient.ConnectionCallbacks，
GooglePlayServicesClient.OnConnectionFailedListener:

@Override
public void onConnected(Bundle bundle) {
        getCurrentLocation();        
}
public void getCurrentLocation() {
    if (this.servicesConnected()) {
        mLocationClient.requestLocationUpdates(mLocationRequest, this);
        mCurrentLocation = mLocationClient.getLastLocation();
        ArrayList<Address> addresses = null;
        try {
            latitude = String.valueOf(mCurrentLocation.getLatitude());
            longitude = String.valueOf(mCurrentLocation.getLongitude());
            addresses = (ArrayList<Address>) gCoder.
                    getFromLocation(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude(), 1);
            mLocationClient.disconnect();
        } catch (IOException e) {
            e.printStackTrace();
        } 
        if (addresses != null && addresses.size() > 0) {
            Log.wtf("Arsnal", "" + addresses.get(0).getLocality());
        } else {
            Toast.makeText(this, R.string.no_address_found, Toast.LENGTH_LONG).show();
        }
        Log.wtf("Location", "Lat " + latitude + " - lon " + longitude);
    }
}

我想要的只是在我的 fragment 中获取字符串纬度和经度

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.wtf("check","Inside OnCreate of Fragment!");
    Log.wtf("check","Latitude"+((MyActivuty)getActivity()).latitude+
"Longitude"+((MyActivuty)getActivity()).longitude);
}

我在这一行中得到了 NPE ie

 Log.wtf("check","Latitude"+((MyActivuty)getActivity()).latitude+
"Longitude"+((MyActivuty)getActivity()).longitude);

因为 onComplete 方法是在 fragment 的 OnCreate() 之后调用的。我该如何解决这个问题？任何帮助表示赞赏!谢谢

Answer 1

在 fragment 中创建一个回调函数:

public void initFragment() {
    // Coordinates are available do something with them
    // ((MyActivuty)getActivity()).latitude
    // ((MyActivuty)getActivity()).longitude
}

然后在您的 Activity 中保存对创建 fragment 的引用:

MyFrag myFrag
...
myFrag = new MyFrag();
...

并在坐标准备就绪时调用 fragment 的函数:

public void getCurrentLocation() {
    ...
    myFrag.initFragment();
}