java.lang.NullPointerException when try listview.getChildAt()

There is ListView with correct values:

public class FragmentTab1 extends SherlockFragment {

ListView list;
LazyAdapter adapter;

@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    list = (ListView) getActivity().findViewById(android.R.id.list); //also I tried view.findViewById(android.R.id.list)
    ............

    adapter = new LazyAdapter(getActivity(), mSource);
    list.setAdapter(adapter);
} 
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
    View rootView = inflater.inflate(R.layout.fragmenttab1, container, false);
    return rootView;

}

when I try:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId(); //correct
    int itemCount = list.getCount();  // 10 ps as show Logcat
    if (R.id.save == id) {
        CheckBox cb;
        for(int i = itemCount - 1; i >= 0; i--) {
            cb = (CheckBox)list.getChildAt(i).findViewById(R.id.checkBox1);  //Error here
        }
    }
    return true;
}

xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<CheckBox
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Save to database"
    android:id="@+id/checkBox1" />  // same id

and adapter is next:

public class LazyAdapter extends BaseAdapter {

private Activity activity;
ArrayList<Bitmap> bitmapArray = new ArrayList<Bitmap>();
private ArrayList<Data> mObjects;
private static LayoutInflater inflater=null;
public ImageLoader imageLoader;

public LazyAdapter(Activity a, ArrayList<Data> mObjects1) {
    activity = a;
    mObjects = mObjects1;
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    imageLoader=new ImageLoader(activity.getApplicationContext());
}

public int getCount() {
    return mObjects.size();
}

public Object getItem(int position) {
    return position;
}

public long getItemId(int position) {
    return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
    Data item = mObjects.get(position);
    View vi=convertView;
    if(convertView==null)
        vi = inflater.inflate(R.layout.item_internet, null);
    TextView text=(TextView)vi.findViewById(R.id.title1);
    ImageView image=(ImageView)vi.findViewById(android.R.id.icon);
    text.setText(item.getmTitle());
    bitmapArray.add(imageLoader.getBitmap());
    imageLoader.DisplayImage(item.getmImageUrl(), image);
    return vi;
}

I receive correct ListView, but receive error when I try click save button from action bar. Probably, I should init CheckBox in adapter? Somebody can help me?

list.getChildAt(i) will be null if the child item is not visible. So check for null before use.

So you cannot retrieve all checked items in this way.

Please post complete .xml and the definition of <Data>.

android, list.getChildAt(i) will be null if the child item is not visible. So check for null before use. So you cannot retrieve all checked items in this way. Please post complete  Exception in thread "main" java.lang.NullPointerException at july_set3.Demo.main(Demo.java:11) According to Java documentation a NullPointerException occurs if you try to − Call the a method (instance) using null object. Access, modify, print, field of a null value (object). Trying to access (print/use in statements) the length of null value.

I'd think you'd get an indexoutofbounds but since it's null, this might be why: ListView getChildAt returning null for visible children

Also, put a log statement in your for loop to display the value of all variables concerned, so: i and itemCount etc.

And set a breakpoint just before the loop and run debug mode to step over to check the values as it loops through and you'll see what i value caused the nullpointer in the debugger or if you miss it, it will be in logcat

Disable the scrolling of list and allow the whole page to scroll, Hi i am currently working on an android application in it has list view inside the main activity. i++) { height += listview.getchildat(i).getmeasuredheight(); height += listview.requestlayout();exception trowing :ava.lang.nullpointerexception: I tried with below methods but throwing "java.lang. getCount() - 1));; myListView​. If you need something else, please do tell, I'll try to help. Best How To : Instead of doing all this you could create a new xml file named listitem.xml with textview as below

ListView, java.lang.annotation ListView. Kotlin |Java. public class ListView extends AbsListView To display a list, you can include a list view in your layout XML file: public View getView(int position, View convertView, ViewGroup container) convertView = getLayoutInflater().inflate(R.layout.list_item, container,  ListView.getChildAt (i) работает, где 0 – первая видимая строка, и (n-1) – последняя видимая строка (где n – количество видимых видов, которые вы видите).

java.lang.NullPointerException and getting crashed on scrolling the , getCount(); i++) { try { TextView LineID = (TextView) listView1.getChildAt(i). ListView; import android.widget.TextView; import java.util.ArrayList; public class Tutorial{ Context c; ListView listView; Activity a; TutorialAdapter chettingAdapter; TextView chettingDatas) { if(chettingDatas.size()>0) { CNoData. Question: Tag: java,android,listview,android-listview,android-adapter I'm developing a NavigationDrawer with ListView.I have a ArrayList<Objetct X> to the items for the ListView

How to fix listview this error attempt to invoke virtual method android , Probably something silly, but I can't figure out where I am getting the null pointer from. If I remove the set of the adapter (last line) there is no exception.

Please try again later. Published on Aug 2, 2017 I've had a problem for a couple of hours where i couldn't get on servers and it said Java.Lang.NullPointerException, I fixed it. and watch the

Comments