Fragments - The specified child already has a pare

问题:

I am getting this error. I tried many solutions but I coudnt solve this. Help me! I need to add the surface view and the button to the activity using fragments.

CamActivity.java:

public class CamActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cam);

        FragmentManager fm = getSupportFragmentManager();

        Fragment fragment = fm.findFragmentById(R.id.fragmentContainer);

        if(fragment == null) {
            fragment = new CamFragment();
            fm.beginTransaction()
            .add(R.id.fragmentContainer, fragment)
            .commit();
        }
    }
}

CamFragment.java:

public class CamFragment extends Fragment {

    private static final String TAG = "CamFragment";

    private Camera mCamera;
    private SurfaceView mSurfaceView;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState){
    View v = inflater.inflate(R.layout.camera_fragment, parent);

    Button capturePic = (Button)v.findViewById(R.id.img_capture);
    capturePic.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            getActivity().finish();
        }
    });

    mSurfaceView = (SurfaceView)v.findViewById(R.id.surfaceView1);
    return v;
}

}

Error:

04-18 13:24:12.735: E/AndroidRuntime(6321): FATAL EXCEPTION: main
04-18 13:24:12.735: E/AndroidRuntime(6321): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pack.camdictionary/com.pack.camdictionary.CamActivity}: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1728)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1747)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.ActivityThread.access$1500(ActivityThread.java:155)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:993)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.os.Handler.dispatchMessage(Handler.java:130)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.os.Looper.loop(SourceFile:351)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.ActivityThread.main(ActivityThread.java:3814)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at java.lang.reflect.Method.invokeNative(Native Method)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at java.lang.reflect.Method.invoke(Method.java:538)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:659)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at dalvik.system.NativeStart.main(Native Method)
04-18 13:24:12.735: E/AndroidRuntime(6321): Caused by: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.view.ViewGroup.addViewInner(ViewGroup.java:2007)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.view.ViewGroup.addView(ViewGroup.java:1902)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.view.ViewGroup.addView(ViewGroup.java:1859)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.view.ViewGroup.addView(ViewGroup.java:1839)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.support.v4.app.NoSaveStateFrameLayout.wrap(NoSaveStateFrameLayout.java:40)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:931)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:570)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1166)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.Activity.performStart(Activity.java:3837)
04-18 13:24:12.735: E/AndroidRuntime(6321):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1701)
04-18 13:24:12.735: E/AndroidRuntime(6321):     ... 11 more

回答1:

Try to replace

View v = inflater.inflate(R.layout.camera_fragment, parent);

With

View v = inflater.inflate(R.layout.camera_fragment, parent, false);

or

View v = inflater.inflate(R.layout.camera_fragment, null);

回答2:

This question had already been answered but still I would like to add the reason for adding false as the third parameter.

The inflate() method takes three arguments:

• The resource ID of the layout you want to inflate.
• The ViewGroup to be the parent of the inflated layout. Passing the container is important in order for the system to apply layout parameters to the root view of the inflated layout, specified by the parent view in which it's going.
• A boolean indicating whether the inflated layout should be attached to the ViewGroup (the second parameter) during inflation. (In this case, this is false because the system is already inserting the inflated layout into the container—passing true would create a redundant view group in the final layout.)

Source: http://developer.android.com/guide/components/fragments.html

回答3:

I am using API 26.0.2 and in my case, the crash was happening because of custom animations set for my fragments. Commenting out the call to set the custom animation, fixed the issue.

fragmentTransaction.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out);

回答4:

Specify Id for parent and child element, especially for custom views, in xml file may solve problem.

回答5:

Just for your reference. It seems to be an issue in the Android SDK.

I have the same situation like @Satheesh had with the SDK version: 27.0.2 and trying to remove the setCustomAnimation seems works. But to remove the setCustomAnimations requires lots of change to make for me, I'd prefer to keep the custom animation. What I have done is to upgrade the SDK to the latest version which is 27.1.1 for now. And it works for me.

回答6:

Might be Helpfull

           View customView1;
           inflater= (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
           customView1= inflater.inflate(R.layout.edit_custom_alert_window, null);     
           try {
                if(customView2.getParent()!=null)
                    ((ViewGroup)customView2.getParent()).removeView(customView2);
            }catch (Exception e){

            }

回答7:

I also met this problem, and this is my solution. it's very easy

View v;

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    if (v == null) {
        v = inflater.inflate(R.layout.camera_fragment, container);
    } else {
        ViewGroup parent = (ViewGroup) v.getParent();
        if (parent != null) {
            parent.removeView(v);
        }
    }
    return v;
}

Hope to be useful to you

回答8:

try this.

 ((CamActivity)getActivity()).finish();