<?xml version="1.0" encoding="utf-8"?><TextView xmlns:android="http://schemas.android.com/apk/res/android"  android:id="@+id/header"  style="@android:style/TextAppearance.Small"  android:layout_width="fill_parent"  android:layout_height="wrap_content"  android:background="#0000ff" />

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="fill_parent"  android:layout_height="fill_parent" >  <ListView    android:id="@android:id/list"    android:layout_width="fill_parent"    android:layout_height="fill_parent" />  <include layout="@layout/header" /></FrameLayout>

<?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="wrap_content"  android:orientation="vertical" >  <include layout="@layout/header" />  <TextView    android:id="@+id/label"    style="@android:style/TextAppearance.Large"    android:layout_width="fill_parent"    android:layout_height="wrap_content" /></LinearLayout>

public class SectionAdapter extends ArrayAdapter<String> { private Activity activity; public SectionAdapter(Activity activity, String[] objects) {  super(activity, R.layout.list_item, R.id.label, objects);//為自定義視圖指定XML布局文件  this.activity = activity; } @Override public View getView(int position, View view, ViewGroup parent) {  if (view == null) {   view = activity.getLayoutInflater().inflate(R.layout.list_item,     parent, false);  }  TextView header = (TextView) view.findViewById(R.id.header);  String label = getItem(position);  if (position == 0//檢查列表項起始字母是否發(fā)生了改變，如果發(fā)生改變，該列表項就是分段中的第一項，修改分段標(biāo)頭的內(nèi)容并顯示該分段標(biāo)頭,否則隱藏    || getItem(position - 1).charAt(0) != label.charAt(0)) {   header.setVisibility(View.VISIBLE);   header.setText(label.substring(0, 1));  } else {   header.setVisibility(View.GONE);//隱藏分段標(biāo)頭  }  return super.getView(position, view, parent); }}

public class Hack26Activity extends ListActivity {  private TextView topHeader;//用于訪問分段標(biāo)頭  private int topVisiblePosition = -1;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.list);    topHeader = (TextView) findViewById(R.id.header);    setListAdapter(new SectionAdapter(this, Countries.COUNTRIES));    //設(shè)置滾動監(jiān)聽器，當(dāng)用戶滾動列表時，檢查位置是否發(fā)生了變化，如果改變，調(diào)用setTopHeader更新懸浮的分段標(biāo)頭，當(dāng)列表第一次顯示時，確保根據(jù)第一個列表項初始化分段標(biāo)頭    getListView().setOnScrollListener(        new AbsListView.OnScrollListener() {          @Override          public void onScrollStateChanged(AbsListView view,                           int scrollState) {            // Empty.          }          @Override          public void onScroll(AbsListView view, int firstVisibleItem,                     int visibleItemCount, int totalItemCount) {            if (firstVisibleItem != topVisiblePosition) {              topVisiblePosition = firstVisibleItem;              setTopHeader(firstVisibleItem);            }          }        });    setTopHeader(0);  }  private void setTopHeader(int pos) {    final String text = Countries.COUNTRIES[pos].substring(0, 1);    topHeader.setText(text);//更新文本內(nèi)容  }}