1 page.title= 2 parent.title=Activity 3 parent.link=activities.html 4 @jd:body 5 <div id="qv-wrapper"> 6 <div id="qv"> 7 <h2></h2> 8 <ol> 9 <li><a href="#summary"> API </a></li> 10 <li><a href="#app"></a> 11 <ol> 12 <li><a href="#requirements"></a></li> 13 <li><a href="#starting"></a></li> 14 <li><a href="#restarting"></a></li> 15 <li><a href="#callback"> LoaderManager </a></li> 16 </ol> 17 </li> 18 <li><a href="#example"></a> 19 <ol> 20 <li><a href="#more_examples"></a></li> 21 </ol> 22 </li> 23 </ol> 24 25 <h2></h2> 26 <ol> 27 <li>{@link android.app.LoaderManager}</li> 28 <li>{@link android.content.Loader}</li> 29 30 </ol> 31 32 <h2></h2> 33 <ol> 34 <li> <a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/LoaderCursor.html">LoaderCursor 35 </a></li> 36 <li> <a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.html">LoaderThrottle 37 </a></li> 38 </ol> 39 </div> 40 </div> 41 42 <p> Android 3.0 Activity 43 </p> 44 <ul> 45 <li> {@link android.app.Activity} {@link 46 android.app.Fragment} </li> 47 <li></li> 48 <li> 49 </li> 50 <li> 51 52 </li> 53 </ul> 54 55 <h2 id="summary"> API </h2> 56 57 <p> 58 </p> 59 60 <table> 61 <tr> 62 <th>/</th> 63 <th></th> 64 </tr> 65 <tr> 66 <td>{@link android.app.LoaderManager}</td> 67 <td> {@link android.app.Activity} 68 {@link android.app.Fragment} {@link 69 android.content.Loader} {@link android.app.Activity} {@link android.app.Fragment} 70 {@link android.content.CursorLoader} 71 72 73 74 <br /> 75 <br /> 76 Activity {@link android.app.LoaderManager} {@link android.app.LoaderManager} 77 </td> 78 </tr> 79 <tr> 80 <td>{@link android.app.LoaderManager.LoaderCallbacks}</td> 81 <td> {@link 82 android.app.LoaderManager} {@link 83 android.app.LoaderManager.LoaderCallbacks#onCreateLoader onCreateLoader()} 84 </td> 85 </tr> 86 <tr> 87 <td>{@link android.content.Loader}</td> 88 <td> 89 {@link 90 android.content.CursorLoader} 91 92 </td> 93 </tr> 94 <tr> 95 <td>{@link android.content.AsyncTaskLoader}</td> 96 <td> {@link android.os.AsyncTask} </td> 97 </tr> 98 <tr> 99 <td>{@link android.content.CursorLoader}</td> 100 <td> 101 {@link android.content.ContentResolver} {@link 102 android.database.Cursor} {@link android.content.AsyncTaskLoader} {@link 103 android.content.Loader} {@link android.content.AsyncTaskLoader} UI 104 105 106 {@link 107 android.content.ContentProvider} Activity API 108 </td> 109 </tr> 110 </table> 111 112 <p> 113 {@link 114 android.app.LoaderManager} 115 {@link android.content.Loader} {@link 116 android.content.CursorLoader} 117 118 </p> 119 120 <h2 id ="app"></h2> 121 <p> Android 122 </p> 123 <ul> 124 <li>{@link android.app.Activity} {@link android.app.Fragment}</li> 125 <li>{@link android.app.LoaderManager} </li> 126 <li> {@link 127 android.content.ContentProvider} {@link android.content.CursorLoader} 128 {@link android.content.Loader} {@link android.content.AsyncTaskLoader} 129 </li> 130 <li>{@link android.app.LoaderManager.LoaderCallbacks} 131 132 </li> 133 <li> {@link 134 android.widget.SimpleCursorAdapter}</li> 135 <li> {@link android.content.CursorLoader} {@link android.content.ContentProvider} 136 </li> 137 </ul> 138 <h3 id="starting"></h3> 139 140 <p>{@link android.app.LoaderManager} {@link android.app.Activity} {@link android.app.Fragment} {@link 141 android.content.Loader} 142 Activity {@link 143 android.app.LoaderManager}</p> 144 145 <p> Activity {@link 146 android.app.Activity#onCreate onCreate()} {@link android.app.Fragment#onActivityCreated onActivityCreated()} {@link android.content.Loader} 147 148 149 </p> 150 151 <pre>// Prepare the loader. Either re-connect with an existing one, 152 // or start a new one. 153 getLoaderManager().initLoader(0, null, this);</pre> 154 155 <p>{@link android.app.LoaderManager#initLoader initLoader()} 156 </p> 157 <ul> 158 <li> ID ID 0</li> 159 <li> (<code>null</code>) 160 </li> 161 162 <li>{@link android.app.LoaderManager.LoaderCallbacks} 163 {@link android.app.LoaderManager} {@link 164 android.app.LoaderManager.LoaderCallbacks} ({@code this}) 165 166 </li> 167 </ul> 168 <p>{@link android.app.LoaderManager#initLoader initLoader()} 169 </p> 170 <ul> 171 <li> ID 172 </li> 173 <li> ID <em></em> 174 {@link android.app.LoaderManager#initLoader initLoader()} 175 {@link android.app.LoaderManager.LoaderCallbacks} {@link android.app.LoaderManager.LoaderCallbacks#onCreateLoader onCreateLoader()} 176 177 <a href="#onCreateLoader">onCreateLoader</a></li> 178 </ul> 179 <p> {@link android.app.LoaderManager.LoaderCallbacks} 180 181 {@link 182 android.app.LoaderManager.LoaderCallbacks#onLoadFinished onLoadFinished()} ( {@link android.app.LoaderManager#initLoader initLoader()} ) 183 184 185 186 <a href="#onLoadFinished">onLoadFinished 187 </a></p> 188 189 <p>{@link android.app.LoaderManager#initLoader initLoader()} {@link android.content.Loader} 190 191 {@link android.app.LoaderManager} 192 {@link android.app.LoaderManager} 193 194 ( <a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.html"> LoaderThrottle</a> ) 195 196 {@link 197 android.app.LoaderManager.LoaderCallbacks} 198 199 <a href="#callback"> LoaderManager </a></p> 200 201 <h3 id="restarting"></h3> 202 203 <p> {@link android.app.LoaderManager#initLoader initLoader()} () ID () 204 205 206 </p> 207 208 <p> {@link 209 android.app.LoaderManager#restartLoader restartLoader()} {@link android.widget.SearchView.OnQueryTextListener} 210 211 212 </p> 213 214 <pre> 215 public boolean onQueryTextChanged(String newText) { 216 // Called when the action bar search text has changed. Update 217 // the search filter, and restart the loader to do a new query 218 // with this filter. 219 mCurFilter = !TextUtils.isEmpty(newText) ? newText : null; 220 getLoaderManager().restartLoader(0, null, this); 221 return true; 222 }</pre> 223 224 <h3 id="callback"> LoaderManager </h3> 225 226 <p>{@link android.app.LoaderManager.LoaderCallbacks} {@link android.app.LoaderManager} 227 </p> 228 <p> ( {@link android.content.CursorLoader}) 229 Activity {@link android.app.Activity#onStop 230 onStop()} {@link android.app.Activity#onStart onStart()} 231 232 233 {@link android.app.LoaderManager.LoaderCallbacks} 234 235 </p> 236 237 <p>{@link android.app.LoaderManager.LoaderCallbacks} 238 </p> 239 <ul> 240 <li>{@link android.app.LoaderManager.LoaderCallbacks#onCreateLoader onCreateLoader()} ID {@link android.content.Loader} 241 242 </li></ul> 243 <ul> 244 <li> {@link android.app.LoaderManager.LoaderCallbacks#onLoadFinished onLoadFinished()} 245 246 </li></ul> 247 <ul> 248 <li>{@link android.app.LoaderManager.LoaderCallbacks#onLoaderReset onLoaderReset()} 249 250 251 </li> 252 </ul> 253 <p></p> 254 255 <h4 id ="onCreateLoader">onCreateLoader</h4> 256 257 <p> ( {@link 258 android.app.LoaderManager#initLoader initLoader()}) ID 259 {@link 260 android.app.LoaderManager.LoaderCallbacks} {@link 261 android.app.LoaderManager.LoaderCallbacks#onCreateLoader onCreateLoader()} 262 {@link 263 android.content.CursorLoader} {@link 264 android.content.Loader} </p> 265 266 <p>{@link 267 android.app.LoaderManager.LoaderCallbacks#onCreateLoader onCreateLoader()} {@link android.content.CursorLoader} 268 269 {@link android.content.CursorLoader} {@link 270 android.content.ContentProvider} 271 </p> 272 <ul> 273 <li>uri<em></em> - URI </li> 274 <li>projection<em></em> - 275 <code>null</code> </li> 276 <li>selection<em></em> - SQL WHERE (WHERE ) 277 278 <code>null</code> URI </li> 279 <li>selectionArgs<em></em> - ?s selectionArgs<em></em> 280 281 </li> 282 <li>sortOrder<em></em> - SQL ORDER BY (ORDER BY ) 283 <code>null</code> 284 </li> 285 </ul> 286 <p></p> 287 <pre> 288 // If non-null, this is the current filter the user has provided. 289 String mCurFilter; 290 ... 291 public Loader<Cursor> onCreateLoader(int id, Bundle args) { 292 // This is called when a new Loader needs to be created. This 293 // sample only has one Loader, so we don't care about the ID. 294 // First, pick the base URI to use depending on whether we are 295 // currently filtering. 296 Uri baseUri; 297 if (mCurFilter != null) { 298 baseUri = Uri.withAppendedPath(Contacts.CONTENT_FILTER_URI, 299 Uri.encode(mCurFilter)); 300 } else { 301 baseUri = Contacts.CONTENT_URI; 302 } 303 304 // Now create and return a CursorLoader that will take care of 305 // creating a Cursor for the data being displayed. 306 String select = "((" + Contacts.DISPLAY_NAME + " NOTNULL) AND (" 307 + Contacts.HAS_PHONE_NUMBER + "=1) AND (" 308 + Contacts.DISPLAY_NAME + " != '' ))"; 309 return new CursorLoader(getActivity(), baseUri, 310 CONTACTS_SUMMARY_PROJECTION, select, null, 311 Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC"); 312 }</pre> 313 <h4 id="onLoadFinished">onLoadFinished</h4> 314 315 <p> 316 317 () 318 319 </p> 320 321 322 <p> 323 {@link 324 android.content.CursorLoader} {@link 325 android.database.Cursor#close close()} 326 {@link android.widget.CursorAdapter} {@link 327 android.widget.SimpleCursorAdapter#swapCursor swapCursor()} 328 {@link android.database.Cursor}</p> 329 330 <pre> 331 // This is the Adapter being used to display the list's data.<br 332 />SimpleCursorAdapter mAdapter; 333 ... 334 335 public void onLoadFinished(Loader<Cursor> loader, Cursor data) { 336 // Swap the new cursor in. (The framework will take care of closing the 337 // old cursor once we return.) 338 mAdapter.swapCursor(data); 339 }</pre> 340 341 <h4 id="onLoaderReset">onLoaderReset</h4> 342 343 <p> 344 345 </p> 346 <p> <code>null</code> 347 {@link android.widget.SimpleCursorAdapter#swapCursor swapCursor()} 348 </p> 349 350 <pre> 351 // This is the Adapter being used to display the list's data. 352 SimpleCursorAdapter mAdapter; 353 ... 354 355 public void onLoaderReset(Loader<Cursor> loader) { 356 // This is called when the last Cursor provided to onLoadFinished() 357 // above is about to be closed. We need to make sure we are no 358 // longer using it. 359 mAdapter.swapCursor(null); 360 }</pre> 361 362 363 <h2 id="example"></h2> 364 365 <p> {@link 366 android.app.Fragment} 367 {@link android.widget.ListView} {@link 368 android.content.CursorLoader} </p> 369 370 <p> {@link android.Manifest.permission#READ_CONTACTS READ_CONTACTS} 371 372 </p> 373 374 <pre> 375 public static class CursorLoaderListFragment extends ListFragment 376 implements OnQueryTextListener, LoaderManager.LoaderCallbacks<Cursor> { 377 378 // This is the Adapter being used to display the list's data. 379 SimpleCursorAdapter mAdapter; 380 381 // If non-null, this is the current filter the user has provided. 382 String mCurFilter; 383 384 @Override public void onActivityCreated(Bundle savedInstanceState) { 385 super.onActivityCreated(savedInstanceState); 386 387 // Give some text to display if there is no data. In a real 388 // application this would come from a resource. 389 setEmptyText("No phone numbers"); 390 391 // We have a menu item to show in action bar. 392 setHasOptionsMenu(true); 393 394 // Create an empty adapter we will use to display the loaded data. 395 mAdapter = new SimpleCursorAdapter(getActivity(), 396 android.R.layout.simple_list_item_2, null, 397 new String[] { Contacts.DISPLAY_NAME, Contacts.CONTACT_STATUS }, 398 new int[] { android.R.id.text1, android.R.id.text2 }, 0); 399 setListAdapter(mAdapter); 400 401 // Prepare the loader. Either re-connect with an existing one, 402 // or start a new one. 403 getLoaderManager().initLoader(0, null, this); 404 } 405 406 @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 407 // Place an action bar item for searching. 408 MenuItem item = menu.add("Search"); 409 item.setIcon(android.R.drawable.ic_menu_search); 410 item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM); 411 SearchView sv = new SearchView(getActivity()); 412 sv.setOnQueryTextListener(this); 413 item.setActionView(sv); 414 } 415 416 public boolean onQueryTextChange(String newText) { 417 // Called when the action bar search text has changed. Update 418 // the search filter, and restart the loader to do a new query 419 // with this filter. 420 mCurFilter = !TextUtils.isEmpty(newText) ? newText : null; 421 getLoaderManager().restartLoader(0, null, this); 422 return true; 423 } 424 425 @Override public boolean onQueryTextSubmit(String query) { 426 // Don't care about this. 427 return true; 428 } 429 430 @Override public void onListItemClick(ListView l, View v, int position, long id) { 431 // Insert desired behavior here. 432 Log.i("FragmentComplexList", "Item clicked: " + id); 433 } 434 435 // These are the Contacts rows that we will retrieve. 436 static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] { 437 Contacts._ID, 438 Contacts.DISPLAY_NAME, 439 Contacts.CONTACT_STATUS, 440 Contacts.CONTACT_PRESENCE, 441 Contacts.PHOTO_ID, 442 Contacts.LOOKUP_KEY, 443 }; 444 public Loader<Cursor> onCreateLoader(int id, Bundle args) { 445 // This is called when a new Loader needs to be created. This 446 // sample only has one Loader, so we don't care about the ID. 447 // First, pick the base URI to use depending on whether we are 448 // currently filtering. 449 Uri baseUri; 450 if (mCurFilter != null) { 451 baseUri = Uri.withAppendedPath(Contacts.CONTENT_FILTER_URI, 452 Uri.encode(mCurFilter)); 453 } else { 454 baseUri = Contacts.CONTENT_URI; 455 } 456 457 // Now create and return a CursorLoader that will take care of 458 // creating a Cursor for the data being displayed. 459 String select = "((" + Contacts.DISPLAY_NAME + " NOTNULL) AND (" 460 + Contacts.HAS_PHONE_NUMBER + "=1) AND (" 461 + Contacts.DISPLAY_NAME + " != '' ))"; 462 return new CursorLoader(getActivity(), baseUri, 463 CONTACTS_SUMMARY_PROJECTION, select, null, 464 Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC"); 465 } 466 467 public void onLoadFinished(Loader<Cursor> loader, Cursor data) { 468 // Swap the new cursor in. (The framework will take care of closing the 469 // old cursor once we return.) 470 mAdapter.swapCursor(data); 471 } 472 473 public void onLoaderReset(Loader<Cursor> loader) { 474 // This is called when the last Cursor provided to onLoadFinished() 475 // above is about to be closed. We need to make sure we are no 476 // longer using it. 477 mAdapter.swapCursor(null); 478 } 479 }</pre> 480 <h3 id="more_examples"></h3> 481 482 <p><strong>ApiDemos</strong> 483 </p> 484 <ul> 485 <li><a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/LoaderCursor.html">LoaderCursor</a> - 486 487 </li> 488 <li><a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/LoaderThrottle.html"> LoaderThrottle</a> - 489 </li> 490 </ul> 491 492 <p> SDK <a href="http://developer.android.com/resources/samples/get.html"></a> 493 </p> 494 495
