android - Fragments - 指定的 child 已经有一个 parent 。您必须先在 child 的 parent 上调用 removeView()

Question

我收到此错误。我尝试了很多解决方案，但我无法解决这个问题。帮我!我需要使用 fragment 将表面 View 和按钮添加到 Activity 中。

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;
}

}

错误:

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

Answer 1

尝试替换

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

有

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

或

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