单击按钮更改ListView项的背景颜色

Question

Apologies if this question has been asked previously.

I have a ListFragment that contains a Button in each list item. Clicking on the Button should change the background color of that particular list item. I understand that the ListView inside the ListFragment refreshes itself implying that if a user scrolls it is likely that a list item that was not previously clicked will have its background color changed.

Many of the solutions I have come across involve storing the position of the list item that was clicked in an overridden getView(int position, View convertView, ViewGroup parent) method implemented in a custom adapter (that extends SimpleAdapter in my case).

However my problem is compounded by the presence of a Button inside every list item implying that the Button will not be clickable unless I attach an OnClickListener inside a custom adapter (this part is done). Now, trying to store the position of the Button's list item fails because the saved position is always a refreshed position and not the absolute position of the list item. I also tried setting tags for each button but even those get recycled as the page scrolls, which is (unfortunately) expected behaviour considering the design of ListView.

I understand that this problem is easily solvable if the a list item does not have children that need to be clicked. But what if there are children within every list item that need to respond to clicks separate from the parent view that contains each list item ? I have also tried using selectors to manipulate a list item's background but that hasn't helped either.

Here is my Custom Adapter's getView method:

@Override
public View getView(int position, View convertView, ViewGroup parent){

    View view = convertView;
    final int pos = position;

    if(view == null){

        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(R.layout.fragment_layout, null);

        Button button = (Button) view.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener(){


            @Override
            public void onClick(View v) {

                Log.d("CLICKED POSITION",Integer.valueOf(pos).toString());
                View parent = (View) v.getParent();

                parent.setBackgroundColor(Color.GREEN);

            }
        });

    }


    return view;
}

And the XML layout file:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="match_parent"
android:orientation="vertical" 
android:layout_weight="1"
android:descendantFocusability="blocksDescendants"
android:layout_margin="5dp" 
>

<ListView android:id="@id/android:list"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 

/> 

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/label" 
        android:layout_gravity="start"
    />

    <TextView 
        android:id="@+id/text_id"
        android:layout_width="0dp"
        android:layout_height="wrap_content" 
        android:layout_weight="1"
        android:layout_gravity="end"
    />

     <Button
         android:id="@+id/button"
         android:layout_height="wrap_content"
         android:layout_width="wrap_content"
         android:text="@string/button"
         android:layout_margin="2dp"
         android:layout_marginLeft="2dp"
         android:layout_marginRight="2dp"
         android:clickable="true"

      />


</LinearLayout> 

I have spent many hours on this problem and I am unable to arrive at a solution. Any direction, guidance or a solution would be most appreciated.

Answer 1

In your Custom Adapter's getView() method, you are inflating the view and attaching the onclicklistener only if the convertView is null. convertView IS the recycled view. If convertView is not null, then you need to change the values in that view. Your getView() method should be like this instead

    @Override
    public View getView(int position, View convertView, ViewGroup parent){

        View view = convertView;
        final int pos = position;
        //No recycled view, so create a new one 
        if(view == null){

            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.fragment_layout, null);

        }
        //By this line, we either have a view that is created in the if block above or passed via convertView
        Button button = (Button) view.findViewById(R.id.button);
        //attach listener to the view, recycled or not
        button.setOnClickListener(new View.OnClickListener(){


                @Override
                public void onClick(View v) {

                    Log.d("CLICKED POSITION",Integer.valueOf(pos).toString());
                    //parent not required as we are have the view directly
                    //View parent = (View) v.getParent();

                    v.setBackgroundColor(Color.GREEN);

                }
            });


        return view;
    }

Indeed you should also be changing any values associated with that item according to that position , if they change. For example, if each button displays the position in the list, you should also add the following line

button.setText("Button " + position);