我尝试使用基于FragmentPagerAdapter的动态创建的标签来实现Cursor，该ListFragment从SQLite DB列中检索不同的值。
然后Cursor根据第二个ListFragment onCreateLoader加载数据，该第二个public class MainActivity extends AppCompatActivity {
// arraylist of tabs in which tab details are stored
private ArrayList<String> tabNames;
// to hold tabs data when first fetch from sqlite db
private Cursor tabCursor;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(com.simsolec.flavorsaver.R.layout.activity_main);
getTabs();
// Create an adapter that knows which fragment should be shown on each page
FlavorFragmentPagerAdapter adapter = new FlavorFragmentPagerAdapter(
getSupportFragmentManager(), MainActivity.this, tabNames);
// Find the view pager that will allow the user to swipe between fragments
ViewPager mViewPager = findViewById(com.simsolec.flavorsaver.R.id.viewpager);
// Set the adapter onto the view pager
mViewPager.setAdapter(adapter);
// Give the TabLayout the ViewPager
TabLayout tabLayout = findViewById(com.simsolec.flavorsaver.R.id.sliding_tabs);
tabLayout.setupWithViewPager(mViewPager);
}
private void getTabs( ){
try{
String[] Projection = { FlavorEntry.COLUMN_FLAVOR_RANGE };
tabCursor = getContentResolver().query(
FlavorEntry.CONTENT_URI_DISTINCT,
Projection,
null,
null,
FlavorEntry.COLUMN_FLAVOR_RANGE );
tabNames = new ArrayList();
tabNames.add("All");
if (tabCursor != null && tabCursor.getCount() > 0) {
if(tabCursor.moveToFirst()) {
do{
String tabName;
tabName = tabCursor.getString(0);
tabNames.add(tabName);
}while (tabCursor.moveToNext());
}
tabCursor.close();
}
}catch (NullPointerException | SQLException e) {
}
finally {
tabCursor.close();
}
}
}根据选项卡名称选择带有过滤器的数据。
最后，我添加了一个Tab以包含＆＃34; All＆＃34;数据，而不是子集。
一切运作良好，除了将正确的数据输入第一个＆＃34;所有＆＃34;片。 public class FlavorFragmentPagerAdapter extends FragmentPagerAdapter {
private Context context;
private ArrayList<String> mTabNames;
public FlavorFragmentPagerAdapter(FragmentManager fm, Context context, ArrayList<String> tabNames) {
super(fm);
this.context = context;
mTabNames = tabNames;
}
@Override
public int getCount() {
//return PAGE_COUNT;
return mTabNames.size();
}
@Override
public Fragment getItem(int position) {
// return FlavorListFragment.newInstance(position + 1);
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
String tabName = mTabNames.get(position);
return FlavorListFragment.newInstance(tabName);
}
@Override
public CharSequence getPageTitle(int position) {
//Generate title based on item position
//return tabTitles[position];
String tabName = mTabNames.get(position);
return tabName;
}
}永远不会选择＆＃34;全部＆＃34;并以某种方式根据第二个Tab的名称在第一个和第二个Tab中提取数据。
我的代码（过滤相关性;希望不要太多）
MainActivity
public class FlavorListFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor>{
// The fragment argument representing the tab name & number for this fragment.
private static final String ARG_TAB_NAME ="tabName";
// Store the tabName for later use
private static String mTabName;
public static FlavorListFragment newInstance(String tabName) {
FlavorListFragment fragment = new FlavorListFragment();
mTabName = tabName;
Bundle args = new Bundle();
args.putString(ARG_TAB_NAME, tabName);
fragment.setArguments(args);
return fragment;
}
/** Identifier for the flavor data loader */
private static final int FLAVOR_LOADER = 0;
/** Adapter for the ListView */
FlavorCursorAdapter mCursorAdapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(com.simsolec.flavorsaver.R.layout.fragment_flavor_list,
container, false);
// Find the ListView which will be populated with the flavor data
ListView flavorListView = rootView.findViewById(com.simsolec.flavorsaver.R.id.flavor_list);
// Setup an Adapter to create a list item for each row of flavor data in the Cursor.
// There is no flavor data yet (until the loader finishes) so pass in null for the Cursor.
mCursorAdapter = new FlavorCursorAdapter(getActivity(), null);
flavorListView.setAdapter(mCursorAdapter);
// Kick off the loader
getLoaderManager().initLoader(FLAVOR_LOADER, null, this);
// Setup the item click listener
flavorListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
// Create new intent to go to {@link FlavorActivity}
Intent intent = new Intent(getContext(), FlavorActivity.class);
// Form the content URI that represents the specific flavor that was clicked on,
// by appending the "id" (passed as input to this method) onto the
// {@link FlavorEntry#CONTENT_URI}.
// For example, the URI would be "content://com.simsolec.flavorsaver/flavors/2"
// if the flavor with ID 2 was clicked on.
Uri currentFlavorUri = ContentUris.withAppendedId(FlavorEntry.CONTENT_URI, id);
// Set the URI on the data field of the intent
intent.setData(currentFlavorUri);
// Launch the {@link FlavorActivity} to display the data for the current flavor.
startActivity(intent);
}
});
return rootView;
}
@Override
public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
// Define a projection that specifies the columns from the table we care about.
String[] projection = {
FlavorEntry._ID,
FlavorEntry.COLUMN_FLAVOR_NAME,
FlavorEntry.COLUMN_DESCRIPTION_SHORT,
FlavorEntry.COLUMN_CUP_IMAGE,
FlavorEntry.COLUMN_RATING };
// This loader will execute the ContentProvider's query method on a background thread
String[] selectionArgs;
if (mTabName=="All") {
selectionArgs = new String[] {"*"};
} else {
selectionArgs = new String[] {mTabName};
}
String selection = FlavorEntry.COLUMN_FLAVOR_RANGE + " in (";
for (int s = 0; s < selectionArgs.length; s++) {
selection += "?, ";
}
selection = selection.substring(0, selection.length() - 2) + ")";
return new CursorLoader(getActivity(), // Parent activity context
FlavorEntry.CONTENT_URI, // Provider content URI to query
projection, // Columns to include in the resulting Cursor
selection, // No selection clause
selectionArgs, // No selection arguments
FlavorEntry.COLUMN_FLAVOR_NAME + " ASC"); // Default sort order
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
// Update {@link FlavorCursorAdapter} with this new cursor containing updated flavor data
mCursorAdapter.swapCursor(data);
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
// Callback called when the data needs to be deleted
mCursorAdapter.swapCursor(null);
}
}
FragmentPagerAdapter
var isDisabled = Xrm.Page.getControl(arg).getDisabled()
ListFragment
Xrm.Page.ui.controls
有人能指出我正确的方向吗？
谢谢你， -Joost
答案 0 :(得分：1)
从Bundle中设置mTabName的值不是从newInstance()方法设置，因为mTabName定义为静态，因此从mTabName删除静态关键字
public static FlavorListFragment newInstance(String tabName) {
FlavorListFragment fragment = new FlavorListFragment();
// mTabName = tabName;
Bundle args = new Bundle();
args.putString(ARG_TAB_NAME, tabName);
fragment.setArguments(args);
return fragment;
}
FlavorListFragment
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(com.simsolec.flavorsaver.R.layout.fragment_flavor_list,
container, false);
Bundle b= getArguments();
//mTabName=b.getString(mTabName);
mTabName=b.getString(ARG_TAB_NAME);
}