以前我使用ZxingFragment爲我的項目,它的工作,但相機的方向是錯誤的。所以現在我正在嘗試Zbar。我正在使用ZbarFragment庫。但問題是我得到Nullpointerexception並從調試值看來,掃描儀類的一些變量爲空。我究竟做錯了什麼?嘗試ZBarFragment,獲得空指針異常
public class ScanFragment extends Fragment implements ZBarFragment.ResultListener {
private static final int ZBAR_SCANNER_REQUEST = 0;
private static final int ZBAR_QR_SCANNER_REQUEST = 1;
private static final String TAG = "ZBarFragment";
private ZBarScanner scanner;
public ScanFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View rootView = inflater.inflate(R.layout.fragment_scan, container, false);
FragmentManager fragmentManager = getFragmentManager();
ZBarFragment cameraFrag = new ZBarFragment();
fragmentManager.beginTransaction()
.replace(R.id.sample, (Fragment)cameraFrag).commit();
scanner = cameraFrag.getScanner();
int[] modes = new int[] {ZBarConstants.CODE128, ZBarConstants.QRCODE};
scanner.setModes(modes);
return rootView;
}
@Override
public void onResult(String result) {
Toast.makeText(getActivity(), result, Toast.LENGTH_LONG).show();
}
}
錯誤日誌:
09-22 00:10:14.538:E/AndroidRuntime(27267):致命異常:主 09-22 00:10:14.538:E/AndroidRuntime( 27267): java.lang.NullPointerException 09-22 00:10:14.538: E/AndroidRuntime(27267):at com.trhura.android.zbar.scanner.ZBarFragment.setModes(ZBarFragment.java:105) 09 -22 00:10:14.538:E/AndroidRuntime(27267):at com.example.devicerentalsystem.ScanFragment.onCreateView(ScanFragment.java:41) 09-22 00:10:14.538:E/AndroidRuntime(27267):at android.support.v4.app.Fragment.performCreateView(Fragment.java:1478) 09-22 00:10:14.538:E/AndroidRuntime (27267):at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927) 09-22 00:10:14.538:E/AndroidRuntime(27267):at android.support.v4.app .FragmentManagerImpl.moveToState(FragmentManager.java:1104) 09-22 00:10:14.538:E/AndroidRuntime(27267):at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 09 -22 00:10:14.538:E/AndroidRuntime(27267):at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460) 09-22 00:10:14.538:E/Andro idRuntime(27267):at android.support.v4.app.FragmentManagerImpl $ 1.run(FragmentManager.java:440) 09-22 00:10:14.538:E/AndroidRuntime(27267):at android.os.Handler .handleCallback(Handler.java:730)09-22 00:10:14.538:E/AndroidRuntime(27267):at android.os.Handler.dispatchMessage(Handler.java:92)09-22 00:10: 14.538:E/AndroidRuntime(27267):在 android.os.Looper.loop(Looper.java:137)09-22 00:10:14.538: E/AndroidRuntime(27267):在 android.app.ActivityThread。 main(ActivityThread.java:5103)09-22 00:10:14.538:E/AndroidRuntime(27267):at java.lang.reflect.Method.invokeNative(Native Method)09-22 00:10:14.538: E /而roidRuntime(27267):at java.lang.reflect.Method.invoke(Method.java:525)09-22 00:10:14.538: E/AndroidRuntime(27267):at com.android.internal.os。 ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:737) 09-22 00:10:14.538:E/AndroidRuntime(27267):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)09 -22 00:10:14.538:E/AndroidRuntime(27267):在 dalvik.system.NativeStart.main(本機方法)