java.lang.IllegalStateException : Fragment not attached to Activity issue in android

Question

在使用 fragment 调用我的 Activity 期间，我遇到了奇怪的问题。我收到类似错误，

java.lang.IllegalStateException: Fragment ScoreFragment{ee2b833 id=0x7f0e0198} not attached to Activity

在第 146 行。我的有错误的 fragment 代码如下所示

if(mPageFlag.equalsIgnoreCase(getString(R.string.winners))){

我的完整代码如下，

 @Override
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
  if (getArguments() != null) {
    mPageFlag = getArguments().getString(ARG_PAGE_FLAG); 
  } 
}

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    if(isVisibleToUser && !mIsPageLoaded){
        mContext = getActivity();
        mIsPageLoaded = true;
        if(mPageFlag.equalsIgnoreCase(getString(R.string.winners))){
            new getcontestscorewinners(mContext).execute();
        }else{ //

            new getcontestscorewinnersNew(mContext).execute();
        }
    }
}


public class getcontestscorewinners extends AsyncTask<String, Void, String> {
    boolean response = false;

    private Context mContext;

    public getcontestscorewinners(Context context) {
        mContext = context;
    }

    @Override
    protected void onPreExecute() {

        progress = ProgressDialog.show(mContext, "Processing...",
                "Please wait....");
    }

    @Override
    protected String doInBackground(String... params) {

        NetworkTask.getContestScoreWinners(winnerHandler);


        return "";

    }

    @Override
    protected void onPostExecute(String result) {


    }

    @Override
    protected void onProgressUpdate(Void... values) {

    }
}

请告诉我是否有人可以帮助我摆脱困境。谢谢。

Answer 1

尝试使用isAdded():

Return true if the fragment is currently added to its activity.

所以你的代码应该是这样的:

if(isAdded() && mPageFlag.equalsIgnoreCase(getString(R.string.winners))){