包含片段的帧布局中的视图的findViewById失败

Question

I have enclosed a fragment in a framelayout...and I am getting the child views of the fragment using the framelayout.

    protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_pan);
    CardFragment fragment=new CardFragment();
    FragmentManager fm=getSupportFragmentManager();
    FragmentTransaction ft=fm.beginTransaction();
    ft.add(R.id.container, fragment);
    container=(FrameLayout)findViewById(R.id.container);
    img_pan=(ImageView)container.findViewById(R.id.img_pan);
    txt_name=(TextView)container.findViewById(R.id.txt_name);
    txt_father=(TextView)container.findViewById(R.id.txt_father);
    txt_dob=(TextView)container.findViewById(R.id.txt_dob);
    txt_type=(TextView)container.findViewById(R.id.txt_type);
    txt_panid=(TextView)container.findViewById(R.id.txt_panid);

}

@Override
public void onResume()
{
    super.onResume();
    Intent i=getIntent();
    String name=i.getStringExtra("pan_name");
    String father=i.getStringExtra("pan_father");
    String dob=i.getStringExtra("pan_dob");
    String type=i.getStringExtra("pan_type");
    String panid=i.getStringExtra("pan_id");
    filePath=i.getStringExtra("pan_filePath");
    Log.d("CardActivity", "Filepath: "+filePath);
    Bitmap bmp=BitmapFactory.decodeFile(filePath);
    if(bmp==null)
    {
        Log.d("CardActivity", "Error getting image to bitmap");
    }
    img_pan.setImageBitmap(bmp);
    txt_name.setText(name);
    txt_father.setText(father);
    txt_dob.setText(dob);
    txt_type.setText(type);
    txt_panid.setText(panid);
}

When I try to add values to the view,it throws a NullPointerException

EDIT:It was working just fine before I seperated everything into a Fragment..

EDIT2:I have changed the Activity and the Fragment as suggested,the Activity onCreate:

   Bundle state=new Bundle();
    state.putString("pan_name", name);
    state.putString("pan_father", father);
    state.putString("pan_dob", dob);
    state.putString("pan_type",type);
    state.putString("pan_id", panid);
    state.putString("pan_filepath", filePath);
    CardFragment fragment=new CardFragment();
    fragment.setArguments(state);
    FragmentManager fm=getSupportFragmentManager();
    FragmentTransaction ft=fm.beginTransaction();
    ft.add(R.id.container, fragment);
    ft.commit();
    if(fm.executePendingTransactions())
    {
        Log.d("CardActivity", "Executed all pending operations");
    }

The fragment onCreateView method:

    public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState)
{
    super.onCreateView(inflater, container, savedInstanceState);
    img_pan=(ImageView)container.findViewById(R.id.img_pan);
    txt_name=(TextView)container.findViewById(R.id.txt_name);
    txt_father=(TextView)container.findViewById(R.id.txt_father);
    txt_dob=(TextView)container.findViewById(R.id.txt_dob);
    txt_type=(TextView)container.findViewById(R.id.txt_type);
    txt_panid=(TextView)container.findViewById(R.id.txt_panid);
    Bundle bundle=getArguments();
    String name=bundle.getString("pan_name");//line 39
    String father=bundle.getString("pan_father");
    String dob=bundle.getString("pan_dob");
    String type=bundle.getString("pan_type");
    String id=bundle.getString("pan_id");
    String filePath=bundle.getString("pan_filepath");
    Bitmap bmp=BitmapFactory.decodeFile(filePath);
    img_pan.setImageBitmap(bmp);
    txt_name.setText(name);
    txt_father.setText(father);
    txt_dob.setText(dob);
    txt_type.setText(type);
    txt_panid.setText(id);

    return inflater.inflate(R.layout.layout_pan, container,false);

}

Now it still returns a NullPointerException,the logcat seems to be pointed at the getArguments().I have tried using saveInstanceState without success.

     E/AndroidRuntime(13367): Caused by: java.lang.NullPointerException
     E/AndroidRuntime(13367):   at     com.example.newscancardapp.CardFragment.onCreateView(CardFragment.java:39)
     E/AndroidRuntime(13367):   at android.support.v4.app.Fragment.performCreateView(Fragment.java:1478)
     E/AndroidRuntime(13367):   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927)
     E/AndroidRuntime(13367):   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
     E/AndroidRuntime(13367):   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1086)
     E/AndroidRuntime(13367):   at  android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1877)
     E/AndroidRuntime(13367):   at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:552)
     E/AndroidRuntime(13367):   at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1133)
     E/AndroidRuntime(13367):   at android.app.Activity.performStart(Activity.java:4529)
     E/AndroidRuntime(13367):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1929)

Edit 3 This code is working:

    public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState)
{
    super.onCreateView(inflater, container, savedInstanceState);
    View pan_layout=inflater.inflate(R.layout.layout_card, container,false);
    img_pan=(ImageView)pan_layout.findViewById(R.id.img_pan);
    txt_name=(TextView)pan_layout.findViewById(R.id.txt_name);
    txt_father=(TextView)pan_layout.findViewById(R.id.txt_father);
    txt_dob=(TextView)pan_layout.findViewById(R.id.txt_dob);
    txt_panid=(TextView)pan_layout.findViewById(R.id.txt_panid);
    Bundle bundle=getArguments();
    String name=bundle.getString("name");
    String father=bundle.getString("father");
    String dob=bundle.getString("dob");
    String id=bundle.getString("id");
    //String filePath=bundle.getString("filepath");
    //Bitmap bmp=BitmapFactory.decodeFile(filePath);
    //img_pan.setImageBitmap(bmp);
    txt_name.setText(name);
    txt_father.setText(father);
    txt_dob.setText(dob);
    txt_panid.setText(id);
    return pan_layout;
}

Having refactored the code into a seperate app for testing...I have disabled the filePath. Thanks to Luksprog for the answer.

Answer 1

I have enclosed a fragment in a framelayout...and I am getting the child views of the fragment using the framelayout.

First of all, in order to actually bind the fragment to the activity you need to call the commit() method on your FragmentTransaction .

Even if you do this, your code will still fail because a fragment transaction is asynchronous, it doesn't happen when you call commit() , it will be scheduled in the future when the main UI thread finishes the current message. To solve this you could call executePendingTransactions() on the FragmentManager you use after committing(but this is not the proper route).

You shouldn't try to work with the views of the fragment directly. As you're trying to initialize the views of the fragment, this should be done either through passing a Bundle with the data as arguments to the fragment when you instantiate it or by making the fragment retrieve it directly from the activity(using getActivity() and casting it to your activity) in one of its callbacks(like onCreateView() ).