Question

I have made linear layout and add view on it, however, the view appear twice, I dont know why it happen.Can anyone fix it??
I have problem about the adapter and I look few time and I find no strange here. But I delete the statement of addView it will not appear any View I have added before.

public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    if(convertView == null)
    {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    //  inflater.inflate(R.layout. parent,false);
        convertView = inflater.inflate(R.layout.exerciseui_item,parent,false);

    }
    Exercise question = exercises.get(position);
    TextView question_view = (TextView) convertView.findViewById(R.id.exercise_question);
    String question_test = question.getOrder() + " " + question.getText()  ;
    question_view.setText(question_test);
    int answer_num = question.getAnswer().size();

    LinearLayout linear = (LinearLayout) convertView.findViewById(R.id.exercise_answer);
        ExerciseAnswer answer = question.getAnswer().get(0);
        int answer_order = answer.getOrder();
        String answer_text = answer.getText();
        String answer_final = answer_order + " " + answer_text;
        TextView answer_view = new TextView(linear.getContext());
        answer_view.setPadding(20, 5, 5, 5);
        answer_view.setTextSize(30);
        answer_view.setText(answer_final);
        linear.addView(answer_view);


    return convertView;
}

The following is the xml of the exerciseui_item

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

<TextView
    android:id="@+id/exercise_question"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"

    android:textSize="13dp"
    ></TextView>
</LinearLayout>

Answer 1

It sounds like view re-cycling might be behind this. Your adapter is responsible for creating the view of each item in the data set (that is the purpose of the getView method). Android, in order to conserve resources, will re-cycle views. That is why the getView method is passed a View. If the passed-in view is non-null, that means it has already been used to display data in this list.

Thus it is the responsibility of the adapter, to “clean up” the view. In your case, that means that you have to account for the fact that you may have already dynamically added the TextView element to this view (in a previous getView call). Failure to “clean up” your view means that each time a view is re-cycled, your method will be adding yet another TextView to the layout.

In your case, I would suggest searching the LinearLayout for the answer TextEdit. (Give this TextEdit an id so that you can find it by using findViewById()). If it already exists, then you do not need to add it.

An other approach would be to include the 2nd TextEdit right in your XML layout. It is not clear to me why this needs to be added dynamically.