ListView 实现分组

1:FragmentHack4.java

/**
 * Created by y on 15-1-2.
 */
public class FragmentHack4 extends Fragment{

    View view;
    List<String> names;

    ListView lvNames;
    NameSectionAdapter adapter;
    TextView tvHeader;
    int topVisiblePos;


    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        names = new ArrayList<String>();

        //测试数据
        String []t={"A","B","C","D","E","F"};
        for(int i=0;i<t.length;i++){
            for(int j=0;j<10;j++){
                names.add(t[i]+"00"+j);
            }
        }

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_hack4, container,false);

        tvHeader = (TextView)view.findViewById(R.id.tvHeader);
        lvNames = (ListView)view.findViewById(R.id.lvNames);

        adapter = new NameSectionAdapter(getActivity(),R.layout.list_name_item,names);
        lvNames.setAdapter(adapter);

        //设置第一个分组栏数据
        setTopHeader(0);

        lvNames.setOnScrollListener( lvOnScrollListener());


        return view;
    }

    AbsListView.OnScrollListener lvOnScrollListener(){
        return new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView absListView, int i) {

            }

            @Override
            public void onScroll(AbsListView absListView, int i, int i2, int i3) {

                if(i!=topVisiblePos){

                    topVisiblePos = i;

                    setTopHeader(i);
                }
            }
        };
    }


    private void setTopHeader(int pos){
        tvHeader.setText(names.get(pos).substring(0,1));
    }
}

2:NameSectionAdapter.java

/**
 * Created by y on 15-1-2.
 */
public class NameSectionAdapter extends ArrayAdapter<String>{
    private int resourceId;

    public NameSectionAdapter(Context context, int resourceId, List<String> objects){
        super(context,resourceId,objects);

        this.resourceId = resourceId;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        String name = getItem(position);
        ViewHolder holder;

        if(convertView==null){
            convertView = LayoutInflater.from(getContext()).inflate(resourceId,null);
            holder = new ViewHolder();

            holder.tvHeader = (TextView)convertView.findViewById(R.id.tvHeader);
            holder.tvName = (TextView)convertView.findViewById(R.id.tvName);

           convertView.setTag(holder);
        }else{
            holder = (ViewHolder)convertView.getTag();
        }

        holder.tvName.setText(name);

        //如果是第一项或者首字母发生了变化,则显示分组栏,否则隐藏
        if(position==0 || getItem(position-1).charAt(0)!=name.charAt(0)){
            holder.tvHeader.setVisibility(View.VISIBLE);
            holder.tvHeader.setText(name.substring(0,1));
        }else{
            holder.tvHeader.setVisibility(View.GONE);
        }

        return convertView;
    }

    static class ViewHolder{
        public TextView tvHeader;
        public TextView tvName;
    }
}

3:布局文件:

(1)fragment_hack4.xml

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

    <ListView
        android:id="@+id/lvNames"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <include layout="@layout/list_header"/>
</FrameLayout>

(2)list_header.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/tvHeader"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#0000ff"
    android:textColor="#ffffff"
    style="@android:style/TextAppearance.Large"
    android:textStyle="bold"/>

(3)list_name_item.xml

<?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="wrap_content"
    android:orientation="vertical">

    <include layout="@layout/list_header"/>

    <TextView
        android:id="@+id/tvName"
        style="@android:style/TextAppearance.Small"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

4:运行结果