android - Unable to start qrCode Camera scanner in fragment -

i have 2 fragments , in 1 of them want have qrcode scanner (using zxingscannerview). however, camera doesn't start , can see black screen. here implementation:

qrcodereaderfragment.java

private zxingscannerview mscannerview; private linearlayout qrcameralayout;  @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate); }  @override public view oncreateview(layoutinflater inflater, viewgroup container,                          bundle savedinstancestate) {      view fragmentview =  inflater.inflate(r.layout.fragment_qr_code_reader, container, false);      qrcameralayout = (linearlayout) fragmentview.findviewbyid(r.id.ll_qrcamera);      mscannerview = new zxingscannerview(getactivity().getapplicationcontext());      mscannerview.setlayoutparams(new linearlayout.layoutparams(             linearlayout.layoutparams.match_parent,             linearlayout.layoutparams.match_parent));      qrcameralayout.addview(mscannerview);      return fragmentview; } 

fragment_qr_code_reader.xml

<framelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="com.letsguang.android.shoppingmalltenant.fragment.qrcodereaderfragment"     android:id="@+id/fl_qrcamera"     >      <linearlayout         android:layout_width="fill_parent"         android:layout_height="fill_parent"         android:id="@+id/ll_qrcamera"         android:orientation="vertical">         </linearlayout>  </framelayout> 

you didn't setup view. according documentation https://github.com/dm77/barcodescanner you've got start/stop camera in onresume/onpause:

@override public void onresume() {     super.onresume();     mscannerview.setresulthandler(this);     mscannerview.startcamera(); }  @override public void onpause() {     super.onpause();     mscannerview.stopcamera(); }