Adding checkboxes dynamically to the fragment - checkboxes are not visible

Question

I'm trying to add checkbox to the fragment which looks like:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/addProductButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:text="Add Product" />


</LinearLayout>

Then I create checkBox and try to add them to the fragment

   @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_product_list, container, false);

            LinearLayout ll = new LinearLayout(getActivity());
            ll.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
            ll.setOrientation(LinearLayout.VERTICAL);
            for (int i = 0; i < 20; i++) {
                CheckBox cb = new CheckBox(rootView.getContext());
                ll.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
                cb.setText("check");
                ll.addView(cb);
            }
            return rootView;
        }
    }

But the checkboxes are not visible.

Answer 1

you can not add the same instance of CheckBox 20times. You need to create a new one at every iteration. Move

inside the for loop

for (int i = 0; i < 20; i++) {
     CheckBox cb = new CheckBox(rootView.getContext());
     ll.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
     cb.setText("check");
     ll.addView(cb);
}

Answer 2

add one id to your linearLayout like:

 android:id="@+id/linearLayout"

then in your code you have:

 LinearLayout ll = rootView.findViewById(R.id.linearLayout);
 // other code

one another way that must work is create one layout and add view and this linearLayout to that

Answer 3

Change Your onCreateView() method like this..no need of findViewById() or any others

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    LinearLayout rootView = (LinearLayout) inflater.inflate(
            R.layout.fragment_product_list, container, false);

    // LinearLayout ll = new LinearLayout(getActivity());
    rootView.setOrientation(LinearLayout.VERTICAL);
    for (int i = 0; i < 20; i++) {
        CheckBox cb = new CheckBox(rootView.getContext());
        rootView.setLayoutParams(new LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
        cb.setText("check");
        rootView.addView(cb);
    }
    return rootView;
}