java.lang.IllegalStateException: Activity has been destroyed SlidingFragmentActivity

Question

I'm new to Android and recently I'm using SlidingMenu(the one on github).When I try to change the MainActivity's fragment when click on the button on slidingmenu I get the error:"java.lang.IllegalStateException: Activity has been destroyed".I think it has something to do with the fragments but can't figure out how to deal with it.

Here's the log

06-07 02:37:58.533: E/AndroidRuntime(31909): java.lang.IllegalStateException: Activity has been destroyed
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1295)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.app.BackStackRecord.commitInternal(BackStackRecord.java:548)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.app.BackStackRecord.commit(BackStackRecord.java:532)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at com.example.ui.MainActivity.switchContent(MainActivity.java:67)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at com.example.ui.SlidingMenuFragment.switchFragment(SlidingMenuFragment.java:110)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at com.example.ui.SlidingMenuFragment.onClick(SlidingMenuFragment.java:100)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.view.View.performClick(View.java:4171)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.view.View$PerformClick.run(View.java:17097)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.os.Handler.handleCallback(Handler.java:615)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.os.Handler.dispatchMessage(Handler.java:92)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.os.Looper.loop(Looper.java:137)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at android.app.ActivityThread.main(ActivityThread.java:4803)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at java.lang.reflect.Method.invokeNative(Native Method)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at java.lang.reflect.Method.invoke(Method.java:511)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-07 02:37:58.533: E/AndroidRuntime(31909):    at dalvik.system.NativeStart.main(Native Method)

Below are the codes MainActivity

public class MainActivity extends SlidingFragmentActivity implements
    OnClickListener {
public static SlidingMenu slidingMenu = null;
private Fragment mContent;

private long exitTime = 0;

@Override
public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    initFragment();
    setContentView(R.layout.activity_main);

    MyApplication.getInstance().addActivity(MainActivity.this);
}

private void initFragment() {
    mContent = new RidingActivityFragment();
    // ridingActivityFragment = new RidingActivityFragment();
    getFragmentManager().beginTransaction()
            .add(R.id.content_frame, mContent).commit();
    setBehindContentView(R.layout.sliding_menu);
    FragmentTransaction fragmentTransaction = getFragmentManager()
            .beginTransaction();
    Fragment aa = new SlidingMenuFragment();
    fragmentTransaction.replace(R.id.content_left, aa);
    fragmentTransaction.commit();

    slidingMenu = getSlidingMenu();
    slidingMenu.setMode(SlidingMenu.LEFT);
    slidingMenu.setBehindOffsetRes(R.dimen.sliding_menu_offset);
    slidingMenu.setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
    case R.id.title_bar_imageview:
        slidingMenu.toggle(true);
        break;

    default:
        break;
    }
}

public void switchContent(Fragment fragment) {
    mContent = fragment;
    getFragmentManager().beginTransaction()
            .replace(R.id.content_frame, fragment).commit();
    getSlidingMenu().showContent();
}

and the SlidingMenuFragment

public class SlidingMenuFragment extends Fragment implements OnClickListener {
private View logoutView = null;
private View sycnView = null;
private View ridingView = null;

private MySharedpreference mySharedpreference = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    View view = inflater.inflate(R.layout.fragment_sliding_menu, container,
            false);

    logoutView = view.findViewById(R.id.toolbox_logout);
    logoutView.setOnClickListener(this);
    sycnView = view.findViewById(R.id.toolbox_sycn);
    sycnView.setOnClickListener(this);
    ridingView = view.findViewById(R.id.toolbox_riding);
    ridingView.setSelected(true);
    ridingView.setOnClickListener(this);

    return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);
}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    Fragment newContent = null;
    switch (v.getId()) {
    case R.id.toolbox_sycn:
        newContent = new SycnActivityFragment();
        sycnView.setSelected(true);
        ridingView.setSelected(false);
        break;

    case R.id.toolbox_riding:
        newContent = new RidingActivityFragment();
        ridingView.setSelected(true);
        sycnView.setSelected(false);
        break;

    default:
        break;
    }

    if (newContent != null) {
        switchFragment(newContent);
    }
}

private void switchFragment(Fragment fragment) {
    if (getActivity() == null) {
        return;
    }

    MainActivity mainActivity = new MainActivity();
    mainActivity.switchContent(fragment);
}

Thanks in advance!

Answer 1

Issue

Your problem consists here: you are trying to create another instance of you activity, inside your fragment:

private void switchFragment(Fragment fragment) {
if (getActivity() == null) {
    return;
}

MainActivity mainActivity = new MainActivity();
    mainActivity.switchContent(fragment);
}

Solution

Instead of this you should getActivity inside fragment and write this code in SlidingMenuFragment :

private void switchFragment(Fragment fragment) {
    if (getActivity() == null) {
        return;
    }

    MainActivity mainActivity = (MainActivity)getActivity();
    mainActivity.switchContent(fragment);
}

It would be a good practice if you would use listeners to communicate to your activity from your fragment