/**  * MultiSelectActivity  */ public class MultiSelectActivity extends Activity implements OnClickListener,     OnItemClickListener {   private static final String TAG = "MultiSelectActivity";   private ListView contactsDelList;   private Button contactsDelBtn;   private Button contactsCancelBtn;   private CheckBox selectAll;   private Cursor cursor;   private ContactsDeleteAdapter contactsDeleteAdapter;    private static final String[] PROJECTION = new String[] { Contacts._ID,       Contacts.DISPLAY_NAME };   private static final int CONTACTS_ID_INDEX = 0;   private static final int DISPLAY_NAME_INDEX = 1;   private ContactsDeleteListItemViews holderViews;    private final class ContactsDeleteListItemViews {     TextView nameView;     CheckBox delCheckBox;   }    @Override   public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.contacts_delete_activity);     contactsDelList = (ListView) findViewById(R.id.contacts_delete_list);     contactsDelBtn = (Button) findViewById(R.id.contacts_delete_btn);     contactsCancelBtn = (Button) findViewById(R.id.contacts_cancel_btn);     selectAll = (CheckBox) (findViewById(R.id.contacts_delete_list_header)         .findViewById(R.id.select_all));     contactsDelList.setOnItemClickListener(this);     contactsDelBtn.setOnClickListener(this);     contactsCancelBtn.setOnClickListener(this);     selectAll.setOnClickListener(this);   }    @Override   protected void onResume() {     super.onResume();     refreshData();   }    // 查詢數據庫   private void refreshData() {     cursor = getContentResolver().query(Contacts.CONTENT_URI, PROJECTION,         null, null, null);     contactsDeleteAdapter = new ContactsDeleteAdapter(this, cursor);     contactsDelList.setAdapter(contactsDeleteAdapter);   }    class ContactsDeleteAdapter extends BaseAdapter {     Cursor cur;     Map<Integer, Boolean> selectedMap;     HashSet<String> delContactsIdSet;      public ContactsDeleteAdapter(Context context, Cursor c) {       cur = c;       // 保存每條記錄是否被選中的狀態       selectedMap = new HashMap<Integer, Boolean>();       // 保存被選中記錄作數據庫表中的Id       delContactsIdSet = new HashSet<String>();        for (int i = 0; i < cur.getCount(); i++) {         selectedMap.put(i, false);       }     }      @Override     public View getView(int position, View convertView, ViewGroup parent) {       if (convertView == null) {         convertView = LayoutInflater.from(MultiSelectActivity.this)             .inflate(R.layout.contacts_delete_list_item, null);         holderViews = new ContactsDeleteListItemViews();         holderViews.nameView = (TextView) convertView             .findViewById(R.id.name);         holderViews.delCheckBox = (CheckBox) convertView             .findViewById(R.id.delete_list_item);         convertView.setTag(holderViews);       }       cur.moveToPosition(position);       ContactsDeleteListItemViews views = (ContactsDeleteListItemViews) convertView           .getTag();       final String name = cur.getString(DISPLAY_NAME_INDEX);       views.nameView.setText(name);       views.delCheckBox.setChecked(selectedMap.get(position));       // 保存記錄Id       if (selectedMap.get(position)) {         delContactsIdSet.add(String.valueOf(cur             .getInt(CONTACTS_ID_INDEX)));       } else {         delContactsIdSet.remove(String.valueOf(cur             .getInt(CONTACTS_ID_INDEX)));       }       return convertView;     }      @Override     public int getCount() {       return cur.getCount();     }      @Override     public Object getItem(int position) {       if (cur.moveToPosition(position)) {         return cur;       } else {         return null;       }     }      @Override     public long getItemId(int position) {       return position;     }   }    @Override   public void onClick(View v) {     switch (v.getId()) {     case R.id.select_all:       // 全選CheckBox的click事件處理       if (selectAll.isChecked()) {         for (int i = 0; i < contactsDeleteAdapter.getCount(); i++) {           contactsDeleteAdapter.selectedMap.put(i, true);           //click事件：全選checkbox被勾選則把所有的聯系人ID添加到delContactsIdSet中           contactsDeleteAdapter.cur.moveToPosition(i);           contactsDeleteAdapter.delContactsIdSet.add(String               .valueOf(contactsDeleteAdapter.cur                   .getInt(CONTACTS_ID_INDEX)));         }         contactsDelBtn.setEnabled(true);       } else {         for (int i = 0; i < contactsDeleteAdapter.getCount(); i++) {           contactsDeleteAdapter.selectedMap.put(i, false);         }         //click事件：全選checkbox被取消勾選則把delContactsIdSet清空         contactsDeleteAdapter.delContactsIdSet.clear();         contactsDelBtn.setEnabled(false);       }       contactsDeleteAdapter.notifyDataSetChanged();       break;     case R.id.contacts_delete_btn:       new AlertDialog.Builder(this).setTitle(           R.string.clearConfirmation_title).setMessage(           R.string.clearConfirmation).setNegativeButton(           android.R.string.cancel, null).setPositiveButton(           android.R.string.ok, new DialogInterface.OnClickListener() {             @Override             public void onClick(DialogInterface dialog, int which) {               final ProgressDialog progressDialog = ProgressDialog                   .show(                       MultiSelectActivity.this,                       getString(R.string.clearProgress_title),                       "", true, false);               final AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>() {                 @Override                 protected Void doInBackground(Void... params) {                   // 刪除記錄事件處理（我這里就不寫詳細的代碼了）                   return null;                 }                  @Override                 protected void onPostExecute(Void result) {                   progressDialog.dismiss();                 }               };               progressDialog.show();               task.execute();             }           }).setCancelable(true).create().show();       break;     case R.id.contacts_cancel_btn:       // 取消事件處理       break;     }   }    @Override   public void onItemClick(AdapterView<?> arg0, View view, int position,       long id) {     Log.i(TAG, "onItemClick");     ContactsDeleteListItemViews views = (ContactsDeleteListItemViews) view         .getTag();     views.delCheckBox.toggle();     contactsDeleteAdapter.selectedMap.put(position, views.delCheckBox         .isChecked());     contactsDeleteAdapter.notifyDataSetChanged();     // 判斷是否有記錄沒被選中，以便修改全選CheckBox勾選狀態     if (contactsDeleteAdapter.selectedMap.containsValue(false)) {       selectAll.setChecked(false);     } else {       selectAll.setChecked(true);     }     // 判斷是否有記錄被選中，以便設置刪除按鈕是否可用     if (contactsDeleteAdapter.selectedMap.containsValue(true)) {       contactsDelBtn.setEnabled(true);     } else {       contactsDelBtn.setEnabled(false);     }   } } 

<?xml version="1.0" encoding="utf-8"?> <!--   zuolongsnail@163.com   This layout of delete contacts. --> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   android:layout_width="match_parent"   android:layout_height="match_parent"   android:orientation="vertical" >    <include     android:id="@+id/contacts_delete_list_header"     layout="@layout/contacts_delete_list_header" />    <ListView     android:id="@+id/contacts_delete_list"     android:layout_width="match_parent"     android:layout_height="0dip"     android:layout_weight="1" />    <LinearLayout     style="@android:style/ButtonBar"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:orientation="horizontal" >      <Button       android:id="@+id/contacts_delete_btn"       android:layout_width="0dip"       android:layout_height="wrap_content"       android:layout_weight="1"       android:enabled="false"       android:text="@string/delete" />      <Button       android:id="@+id/contacts_cancel_btn"       android:layout_width="0dip"       android:layout_height="wrap_content"       android:layout_weight="1"       android:text="@string/cancel" />   </LinearLayout>  </LinearLayout>