如何在ListView上添加节标题

Question

我开发了一个“国家管理”应用程序。我在我的应用程序上使用ListView。我的Listview已准备就绪，可以正常工作。我想在我的应用程序中添加“国家/地区”部分标题。拜托，有人帮我解决这个问题。 这是我的代码。

MainActivity.java

public class MainActivity extends AppCompatActivity {

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final ArrayList<PageData> data = new ArrayList<PageData>();
//        Africa  (Here should add country Header)
        data.add(new PageData(R.drawable.ic_launcher, "Algeria"));
        data.add(new PageData(R.drawable.ic_launcher, "Egypt"));
        data.add(new PageData(R.drawable.ic_launcher, "Ethiopia"));
        data.add(new PageData(R.drawable.ic_launcher, "Ghana"));
//        Asia (Here should add country Header)
        data.add(new PageData(R.drawable.ic_launcher, "Bangladesh"));
        data.add(new PageData(R.drawable.ic_launcher, "India"));
        data.add(new PageData(R.drawable.ic_launcher, "Pakistan"));
        data.add(new PageData(R.drawable.ic_launcher, "Japan"));
//        Europe (Here should add country Header)
        data.add(new PageData(R.drawable.ic_launcher, "Belgium"));
        data.add(new PageData(R.drawable.ic_launcher, "Finland"));
        data.add(new PageData(R.drawable.ic_launcher, "Italy"));
        data.add(new PageData(R.drawable.ic_launcher, "Poland"));
//        America (Here should add country Header)
        data.add(new PageData(R.drawable.ic_launcher, "Canada "));
        data.add(new PageData(R.drawable.ic_launcher, "USA"));
        data.add(new PageData(R.drawable.ic_launcher, "Mexico"));
        data.add(new PageData(R.drawable.ic_launcher, "Bermuda"));
//        Australia (Here should add country Header)
        data.add(new PageData(R.drawable.ic_launcher, "Australia"));
        data.add(new PageData(R.drawable.ic_launcher, "Fiji"));
        data.add(new PageData(R.drawable.ic_launcher, "New Zealand"));
        data.add(new PageData(R.drawable.ic_launcher, "Papua New Guinea"));

        final ListView lv = (ListView) findViewById(R.id.list_view);
        final ListViewAdapter lva = new ListViewAdapter(this, R.layout.listview_item, data);
        lv.setAdapter(lva);

        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                PageData pd =  data.get(position);
                Toast.makeText(MainActivity.this.getBaseContext(), pd.getTitle(), Toast.LENGTH_SHORT).show();
            }
        });

    }
}

activity_main.xml

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

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbarAlwaysDrawVerticalTrack="true"
        android:scrollbars="vertical" />


</LinearLayout>

listview_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/image_view"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_marginTop="0dp"
        android:src="@drawable/ic_launcher" />


    <TextView
        android:id="@+id/item_label"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp" />

</LinearLayout>

ListViewAdapter.java

public class ListViewAdapter extends ArrayAdapter<PageData> {
    protected List<PageData> data;
    protected LayoutInflater inflater;

    public ListViewAdapter(Activity activity, int textViewResourceId, List<PageData> objects){
        super(activity, textViewResourceId, objects);
        data= objects;
    }

    public View getView(final int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View row = inflater.inflate(R.layout.listview_item, parent, false);
        PageData pd = data.get(position);
        ImageView iv = (ImageView) row.findViewById(R.id.image_view);
        iv.setImageResource(pd.getPicture());
        TextView tv = (TextView)row.findViewById(R.id.item_label);
        tv.setText(Html.fromHtml(pd.getTitle()));
        return row;
    }
}

PageData.java

public class PageData implements Parcelable {
    private int picture;
    private String title;

    public PageData() {
    }

    public PageData(Parcel in) {
        picture = in.readInt();
        title = in.readString();

    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(picture);
        dest.writeString(title);

    }

    public PageData(int picture, String title) {
        this.picture = picture;
        this.title = title;

    }

    public int getPicture() {
        return picture;
    }

    public String getTitle() {
        return title;
    }

}