9.7. Activities Change the coding of your activities to the following. First TodosOverviewActivity.java. package de.vogella.android.todos; import android.app.ListActivity; import android.app.LoaderManager; import android.content.CursorLoader; import android.content.Intent; import android.content.Loader; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.view.ContextMenu; import android.view.ContextMenu.ContextMenuInfo; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.widget.AdapterView.AdapterContextMenuInfo; import android.widget.ListView; import android.widget.SimpleCursorAdapter; import de.vogella.android.todos.contentprovider.MyTodoContentProvider; import de.vogella.android.todos.database.TodoTable; /* * TodosOverviewActivity displays the existing todo items * in a list * * You can create new ones via the ActionBar entry "Insert" * You can delete existing ones via a long press on the item */ public class TodosOverviewActivity extends ListActivity implements LoaderManager.LoaderCallbacks { private static final int ACTIVITY_CREATE = 0; private static final int ACTIVITY_EDIT = 1; private static final int DELETE_ID = Menu.FIRST + 1; // private Cursor cursor; private SimpleCursorAdapter adapter; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.todo_list); this.getListView().setDividerHeight(2); fillData(); registerForContextMenu(getListView()); } // Create the menu based on the XML defintion @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.listmenu, menu); return true; } // Reaction to the menu selection @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.insert: createTodo(); return true; } return super.onOptionsItemSelected(item); } @Override public boolean onContextItemSelected(MenuItem item) { switch (item.getItemId()) { case DELETE_ID: AdapterContextMenuInfo info = (AdapterContextMenuInfo) item .getMenuInfo(); Uri uri = Uri.parse(MyTodoContentProvider.CONTENT_URI + "/" + info.id); getContentResolver().delete(uri, null, null); fillData(); return true; } return super.onContextItemSelected(item); } private void createTodo() { Intent i = new Intent(this, TodoDetailActivity.class); startActivity(i); } // Opens the second activity if an entry is clicked @Override protected void onListItemClick(ListView l, View v, int position, long id) { super.onListItemClick(l, v, position, id); Intent i = new Intent(this, TodoDetailActivity.class); Uri todoUri = Uri.parse(MyTodoContentProvider.CONTENT_URI + "/" + id); i.putExtra(MyTodoContentProvider.CONTENT_ITEM_TYPE, todoUri); startActivity(i); } private void fillData() { // Fields from the database (projection) // Must include the _id column for the adapter to work String[] from = new String[] { TodoTable.COLUMN_SUMMARY }; // Fields on the UI to which we map int[] to = new int[] { R.id.label }; getLoaderManager().initLoader(0, null, this); adapter = new SimpleCursorAdapter(this, R.layout.todo_row, null, from, to, 0); setListAdapter(adapter); } @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); menu.add(0, DELETE_ID, 0, R.string.menu_delete); } // Creates a new loader after the initLoader () call @Override public Loader onCreateLoader(int id, Bundle args) { String[] projection = { TodoTable.COLUMN_ID, TodoTable.COLUMN_SUMMARY }; CursorLoader cursorLoader = new CursorLoader(this, MyTodoContentProvider.CONTENT_URI, projection, null, null, null); return cursorLoader; } @Override public void onLoadFinished(Loader loader, Cursor data) { adapter.swapCursor(data); } @Override public void onLoaderReset(Loader loader) { // data is not available anymore, delete reference adapter.swapCursor(null); } }
Posted on: Fri, 27 Sep 2013 05:43:28 +0000
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