Android中ListView的分段標(biāo)頭怎么進(jìn)行添加

<&#63;xml version="1.0" encoding="utf-8"&#63;>

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/header"
  
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:background="#0000ff" />

<&#63;xml version="1.0" encoding="utf-8"&#63;>

<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>

<&#63;xml version="1.0" encoding="utf-8"&#63;>

<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"
    
    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(xiàng)起始字母是否發(fā)生了改變，如果發(fā)生改變，該列表項(xiàng)就是分段中的第一項(xiàng)，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(dòng)監(jiān)聽器，當(dāng)用戶滾動(dòng)列表時(shí)，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(shí)，確保根據(jù)第一個(gè)列表項(xiàng)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
  }
}