Question

我正在使用UI上的长按从我的本地数据库中删除一行，删除后，该行将从用户界面的列表中自动删除。

public class AllData extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {

DotCursorAdapter mAdapter;
private ListView lv;
Context context = this;
private  final int LOADER_ID = 860;
public static DatabaseHandler dbHelper;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);



        lv = (ListView) findViewById(R.id.lists);


        dbHelper = new DatabaseHandler(this);

        mAdapter = new DotCursorAdapter(this, null, 1);
        getSupportLoaderManager().initLoader(LOADER_ID, null, this);
        lv.setAdapter(mAdapter);

        lv.setTextFilterEnabled(true);


}

@Override
public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
    return new DumbLoader(this);
}
@Override
public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {


    mAdapter.swapCursor(cursor);


}
@Override
public void onLoaderReset(Loader<Cursor> cursorLoader) {
    mAdapter.swapCursor(null);
}

/**
 * DumbLoader sub class
 */
public static class DumbLoader extends CursorLoader {


    public DumbLoader(Context context) {
        super(context);
    }

    @Override
    public Cursor loadInBackground() {
        Cursor c = dbHelper.FetchAllData();
        return c;

    }
}
public final class DotCursorAdapter extends CursorAdapter {

    public DotCursorAdapter(Context context, Cursor cursor, int flags) {
        super(context, cursor, 0);
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        return LayoutInflater.from(context).inflate(R.layout.visitation_activity, parent, false);
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {

        /**
         * Data from the local database
         */
        final String id = cursor.getString(cursor.getColumnIndexOrThrow("_id"));
        final String date = cursor.getString(cursor.getColumnIndexOrThrow("created_at"));


        view.setTag(Long.valueOf(id));
        view.setOnLongClickListener(new View.OnLongClickListener() {

            @Override
            public boolean onLongClick(View view) {
                ((AllData) mContext).deleteData(((Long) view.getTag()).longValue());
                return true;
            }
        });


    }
}


/**
 * Delete data and update list view
 */
public void deleteData(long id) {
    final long alarmId = id;
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Please confirm")
            .setTitle("Delete set?")
            .setCancelable(true)
            .setNegativeButton("Cancel", null)
            .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dbHelper.deleteData(alarmId);
                    //Refresh the list of the alarms in the adaptor
                    dbHelper.FetchAllData();
                    //Notify the adapter the data has changed
                    mAdapter.notifyDataSetChanged();
                }

            }).show();
}}

使用上面的代码，我可以从本地数据库中删除数据，但它不会从用户界面中删除已删除的行，除非我刷新页面。

有没有办法在删除后自动从列表视图中删除已删除的行。提前谢谢。

Answer 1

使用此getSupportLoaderManager().restartLoader(0, null, AllData.this);代替mAdapter.notifyDataSetChanged();来刷新列表项

Answer 2

或者您可以使用intent并保持源活动和目标活动相同.....并在删除行后使用此行

  Intent i = new Intent(sourceActivity.this,targetActivity.this);
  startActivity(i);
   sourceActivity.finish();

删除android中的行后如何更新列表视图

2 个答案: