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基于ListView和CheckBox实现多选和全选记录的功能

2011-02-27 12:07 302 查看
 应用开发中经常会有从数据库中读取数据显示,然后选中多条、全部记录并且删除的需求。在做定制系统联系人的时候也遇到这样的需求,下面写个简单的通过ListView和CheckBox实现多选、全选的例子。下面是具体的代码,有问题请留言。代码下载地址:



  MultiSelectActivity
/**  * @author  * 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();  }  // 查询数据库  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;  // 保存每条记录是否被选中的状态  selectedMap = new HashMap<Integer, Boolean>();  // 保存被选中记录作数据库表中的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));  // 保存记录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:  // 全选CheckBox的click事件处理  if (selectAll.isChecked()) {  for (int i = 0; i < contactsDeleteAdapter.getCount(); i++) {  contactsDeleteAdapter.selectedMap.put(i, true);  //click事件:全选checkbox被勾选则把所有的联系人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:全选checkbox被取消勾选则把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) {  // 删除记录事件处理(我这里就不写详细的代码了)  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:  // 取消事件处理  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();  // 判断是否有记录没被选中,以便修改全选CheckBox勾选状态  if (contactsDeleteAdapter.selectedMap.containsValue(false)) {  selectAll.setChecked(false);  } else {  selectAll.setChecked(true);  }  // 判断是否有记录被选中,以便设置删除按钮是否可用  if (contactsDeleteAdapter.selectedMap.containsValue(true)) {  contactsDelBtn.setEnabled(true);  } else {  contactsDelBtn.setEnabled(false);  }  }  }

  布局文件:contacts_delete_activity.xml
<?xml version="1.0" encoding="utf-8"?>  <!--  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>

本文出自 “Android小子的” 博客,请务必保留此出处http://androidrigl.blog.51cto.com/7531835/1249470
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